Installing a cluster on bare metal

Prerequisites
Machine requirements for a cluster with user-provisioned infrastructure
Creating the user-provisioned infrastructure
- Networking requirements for user-provisioned infrastructure
- User-provisioned DNS requirements
Generating an SSH private key and adding it to the agent
Obtaining the installation program
Installing the OpenShift CLI by downloading the binary
Manually creating the installation configuration file
- Sample install-config.yaml file for bare metal
- Configuring the cluster-wide proxy during installation
Configuring a three-node cluster
Creating the Kubernetes manifest and Ignition config files
Creating Fedora CoreOS (FCOS) machines
Creating the cluster
Logging in to the cluster by using the CLI
Approving the certificate signing requests for your machines
Initial Operator configuration
- Image registry removed during installation
- Image registry storage configuration
Completing installation on user-provisioned infrastructure
Next steps

In OKD version 4, you can install a cluster on bare metal infrastructure that you provision.

While you might be able to follow this procedure to deploy a cluster on virtualized or cloud environments, you must be aware of additional considerations for non-bare metal platforms. Review the information in the guidelines for deploying OKD on non-tested platforms before you attempt to install an OKD cluster in such an environment.

Prerequisites

Review details about the OKD installation and update processes.
If you use a firewall, you must configure it to allow the sites that your cluster requires access to.

Be sure to also review this site list if you are configuring a proxy.

Machine requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

Required machines

The smallest OKD clusters require the following hosts:

One temporary bootstrap machine
Three control plane, or master, machines
At least two compute machines, which are also known as worker machines. If you are running a three-node cluster, running zero compute machines is supported. Running one compute machine is not supported.

The cluster requires the bootstrap machine to deploy the OKD cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap, control plane, and compute machines must use the Fedora CoreOS (FCOS) as the operating system.

See Red Hat Enterprise Linux technology capabilities and limits.

Network connectivity requirements

All the Fedora CoreOS (FCOS) machines require network in initramfs during boot to fetch Ignition config files from the Machine Config Server. During the initial boot, the machines require either a DHCP server or that static IP addresses be set in order to establish a network connection to download their Ignition config files.

Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

Machine	Operating System	vCPU¹	Virtual RAM	Storage
Bootstrap	FCOS	4	16 GB	120 GB
Control plane	FCOS	4	16 GB	120 GB
Compute	FCOS	2	8 GB	120 GB
¹ 1 physical core provides 2 vCPUs when hyper-threading is enabled. 1 physical core provides 1 vCPU when hyper-threading is not enabled.

Machine

Operating System

vCPU¹

Virtual RAM

Storage

Bootstrap

FCOS

16 GB

120 GB

Control plane

FCOS

16 GB

120 GB

Compute

FCOS

8 GB

120 GB

¹ 1 physical core provides 2 vCPUs when hyper-threading is enabled. 1 physical core provides 1 vCPU when hyper-threading is not enabled.

Certificate signing requests management

Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.

Creating the user-provisioned infrastructure

Before you deploy an OKD cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Review the OKD 4.x Tested Integrations page before you create the supporting infrastructure for your cluster.

Procedure

Configure DHCP or set static IP addresses on each node.
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

Networking requirements for user-provisioned infrastructure

All the Fedora CoreOS (FCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

During the initial boot, the machines require either a DHCP server or that static IP addresses be set on each host in the cluster to establish a network connection, which allows them to download their Ignition config files.

It is recommended to use the DHCP server to manage the machines for the cluster long-term. Ensure that the DHCP server is configured to provide persistent IP addresses and host names to the cluster machines.

The Kubernetes API server must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 1. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101` and the Cluster Version Operator on port `9099`.
	`10250`-`10259`	The default ports that Kubernetes reserves
	`10256`	openshift-sdn
UDP	`4789`	VXLAN and Geneve
	`6081`	VXLAN and Geneve
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101`.
TCP/UDP	`30000`-`32767`	Kubernetes node port

Table 2. All machines to control plane
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server, peer, and metrics ports
TCP	`6443`	Kubernetes API

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

OKD requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Load balancers

Before you install OKD, you must provision two load balancers that meet the following requirements:

API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
A stateless load balancing algorithm. The options vary based on the load balancer implementation.

Session persistence is not required for the API load balancer to function properly.

Configure the following ports on both the front and back of the load balancers:

Table 3. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`6443`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the `/readyz` endpoint for the API server health check probe.	X	X	Kubernetes API server
`22623`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.	X		Machine config server

The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the /readyz endpoint to the removal of the API server instance from the pool. Within the time frame after /readyz returns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values.

Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.
A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.

Configure the following ports on both the front and back of the load balancers:

Table 4. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`443`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTPS traffic
`80`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTP traffic

If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

A working configuration for the Ingress router is required for an OKD cluster. You must configure the Ingress router after the control plane initializes.

User-provisioned DNS requirements

DNS is used for name resolution and reverse name resolution. DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Fedora CoreOS (FCOS) uses the reverse records to set the host name for all the nodes. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OKD needs to operate.

The following DNS records are required for an OKD cluster that uses user-provisioned infrastructure. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Component Record Description

Kubernetes API

api.<cluster_name>.<base_domain>.

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

api-int.<cluster_name>.<base_domain>.

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster.

The API server must be able to resolve the worker nodes by the host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.

Routes

*.apps.<cluster_name>.<base_domain>.

Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.

Bootstrap

bootstrap.<cluster_name>.<base_domain>.

Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.

Master hosts

<master><n>.<cluster_name>.<base_domain>.

Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the master nodes. These records must be resolvable by the nodes within the cluster.

Worker hosts

<worker><n>.<cluster_name>.<base_domain>.

Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

The following example of a BIND zone file shows sample A records for name resolution. The purpose of the example is to show the records that are needed. The example is not meant to provide advice for choosing one name resolution service over another.

Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.ocp4.example.com.
5	IN	PTR	api-int.ocp4.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

Generating an SSH private key and adding it to the agent

If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent and the installation program. You can use this key to access the bootstrap machine in a public cluster to troubleshoot installation issues.

In a production environment, you require disaster recovery and debugging.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs.

On clusters running Fedora CoreOS (FCOS), the SSH keys specified in the Ignition config files are written to the /home/core/.ssh/authorized_keys.d/core file. However, the Machine Config Operator manages SSH keys in the /home/core/.ssh/authorized_keys file and configures sshd to ignore the /home/core/.ssh/authorized_keys.d/core file. As a result, newly provisioned OKD nodes are not accessible using SSH until the Machine Config Operator reconciles the machine configs with the authorized_keys file. After you can access the nodes using SSH, you can delete the /home/core/.ssh/authorized_keys.d/core file.

Procedure

If you do not have an SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:
```
$ ssh-keygen -t ed25519 -N '' \
    -f <path>/<file_name> (1)
```
1 Specify the path and file name, such as ~/.ssh/id_rsa, of the new SSH key.

Running this command generates an SSH key that does not require a password in the location that you specified.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"
```
Example output
```
Agent pid 31874
```
Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> (1)
```
Example output
```
Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
```
1 Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

When you install OKD, provide the SSH public key to the installation program. If you install a cluster on infrastructure that you provision, you must provide this key to your cluster’s machines.

Obtaining the installation program

Before you install OKD, download the installation file on a local computer.

Prerequisites

You have a computer that runs Linux or macOS, with 500 MB of local disk space

Procedure

Download installer from https://github.com/openshift/okd/releases

The installation program creates several files on the computer that you use to install your cluster. You must keep the installation program and the files that the installation program creates after you finish installing the cluster. Both files are required to delete the cluster.

Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OKD uninstallation procedures for your specific cloud provider.

Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:
```
$ tar xvf openshift-install-linux.tar.gz
```
From the Pull Secret page on the Red Hat OpenShift Cluster Manager site, download your installation pull secret as a .txt file. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OKD components.

If you do not use the pull secret from the Red Hat OpenShift Cluster Manager site:
- Red Hat Operators are not available.
- The Telemetry and Insights operators do not send data to Red Hat.
- Content from the Red Hat Container Catalog registry, such as image streams and Operators, are not available.

Installing the OpenShift CLI by downloading the binary

You can install the OpenShift CLI (oc) in order to interact with OKD from a command-line interface. You can install oc on Linux, Windows, or macOS.

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OKD 4. Download and install the new version of oc.

Installing the OpenShift CLI on Linux

You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.

Procedure

Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.
Download oc.tar.gz.
Unpack the archive:
```
$ tar xvzf <file>
```
Place the oc binary in a directory that is on your PATH.

To check your PATH, execute the following command:
```
$ echo $PATH
```

After you install the CLI, it is available using the oc command:

$ oc <command>

Installing the OpenShift CLI on Windows

You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.

Procedure

Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.
Download oc.zip.
Unzip the archive with a ZIP program.
Move the oc binary to a directory that is on your PATH.

To check your PATH, open the command prompt and execute the following command:
```
C:\> path
```

After you install the CLI, it is available using the oc command:

C:\> oc <command>

Installing the OpenShift CLI on macOS

You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.

Procedure

Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.
Download oc.tar.gz.
Unpack and unzip the archive.
Move the oc binary to a directory on your PATH.

To check your PATH, open a terminal and execute the following command:
```
$ echo $PATH
```

After you install the CLI, it is available using the oc command:

$ oc <command>

Manually creating the installation configuration file

For installations of OKD that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

Obtain the OKD installation program and the access token for your cluster.

Procedure

Create an installation directory to store your required installation assets in:

$ mkdir <installation_directory>

You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OKD version.

Customize the following install-config.yaml file template and save it in the <installation_directory>.

You must name this configuration file install-config.yaml.
Back up the install-config.yaml file so that you can use it to install multiple clusters.

The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

Sample `install-config.yaml` file for bare metal

You can customize the install-config.yaml file to specify more details about your OKD cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com (1)
compute:
- hyperthreading: Enabled  (2) (3)
  name: worker
  replicas: 0 (4)
controlPlane:
  hyperthreading: Enabled  (2) (3)
  name: master (3)
  replicas: 3 (5)
metadata:
  name: test (6)
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 (7)
    hostPrefix: 23 (8)
  networkType: OVNKubernetes
  serviceNetwork: (9)
  - 172.30.0.0/16
platform:
  none: {} (10)
fips: false (11)
pullSecret: '{"auths": ...}' (12)
sshKey: 'ssh-ed25519 AAAA...' (13)

1 The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.

2 The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Although both sections currently define a single machine pool, it is possible that future versions of OKD will support defining multiple compute pools during installation. Only one control plane pool is used.

Whether to enable or disable simultaneous multithreading, or hyperthreading. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable simultaneous multithreading in some cluster machines, you must disable it in all cluster machines.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

4 You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OKD.

5 The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.

6 The cluster name that you specified in your DNS records.

7 A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.

8 The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.

9 The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.

10 You must set the platform to none. You cannot provide additional platform configuration variables for your platform.

11 Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Fedora CoreOS (FCOS) machines that OKD runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with FCOS instead.

12 The pull secret that you obtained from the Pull Secret page on the Red Hat OpenShift Cluster Manager site. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OKD components.

The public portion of the default SSH key for the core user in Fedora CoreOS (FCOS).

For production OKD clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

Configuring the cluster-wide proxy during installation

Production environments can deny direct access to the Internet and instead have an HTTP or HTTPS proxy available. You can configure a new OKD cluster to use a proxy by configuring the proxy settings in the install-config.yaml file.

For bare metal installations, if you do not assign node IP addresses from the range that is specified in the networking.machineNetwork[].cidr field in the install-config.yaml file, you must include them in the proxy.noProxy field.

Prerequisites

You have an existing install-config.yaml file.

You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.

The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.

For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

Edit your install-config.yaml file and add the proxy settings. For example:

apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> (1)
  httpsProxy: http://<username>:<pswd>@<ip>:<port> (2)
  noProxy: example.com (3)
additionalTrustBundle: | (4)
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...

1	A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be `http`. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an `httpProxy` value.
2	A proxy URL to use for creating HTTPS connections outside the cluster. If this field is not specified, then `httpProxy` is used for both HTTP and HTTPS connections. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an `httpsProxy` value.
3	A comma-separated list of destination domain names, domains, IP addresses, or other network CIDRs to exclude proxying. Preface a domain with `.` to include all subdomains of that domain. Use `*` to bypass proxy for all destinations.
4	If provided, the installation program generates a config map that is named `user-ca-bundle` in the `openshift-config` namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a `trusted-ca-bundle` config map that merges these contents with the Fedora CoreOS (FCOS) trust bundle, and this config map is referenced in the `Proxy` object’s `trustedCA` field. The `additionalTrustBundle` field is required unless the proxy’s identity certificate is signed by an authority from the FCOS trust bundle. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must provide the MITM CA certificate.

The installation program does not support the proxy readinessEndpoints field.

Save the file and reference it when installing OKD.

The installation program creates a cluster-wide proxy that is named cluster that uses the proxy settings in the provided install-config.yaml file. If no proxy settings are provided, a cluster Proxy object is still created, but it will have a nil spec.

Only the Proxy object named cluster is supported, and no additional proxies can be created.

Configuring a three-node cluster

You can optionally install and run three-node clusters in OKD with no workers. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for development, production, and testing.

Procedure

Edit the install-config.yaml file to set the number of compute replicas, which are also known as worker replicas, to 0, as shown in the following compute stanza:
```
compute:
- name: worker
  platform: {}
  replicas: 0
```

Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to make its machines.

The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to create the cluster.

The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.

Prerequisites

You obtained the OKD installation program.
You created the install-config.yaml installation configuration file.

Procedure

Change to the directory that contains the installation program and generate the Kubernetes manifests for the cluster:

$ ./openshift-install create manifests --dir=<installation_directory> (1)

Example output

INFO Credentials loaded from the "myprofile" profile in file "/home/myuser/.aws/credentials"
INFO Consuming Install Config from target directory
INFO Manifests created in: install_dir/manifests and install_dir/openshift

1	For `<installation_directory>`, specify the installation directory that contains the `install-config.yaml` file you created.

If you are running a three-node cluster, skip the following step to allow the masters to be schedulable.

Check that the mastersSchedulable parameter in the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file is set to false. This setting prevents pods from being scheduled on the control plane machines:
1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
2. Locate the mastersSchedulable parameter and ensure that it is set to false.
3. Save and exit the file.

To create the Ignition configuration files, run the following command from the directory that contains the installation program:

$ ./openshift-install create ignition-configs --dir=<installation_directory> (1)

1	For `<installation_directory>`, specify the same installation directory.

The following files are generated in the directory:

.
├── auth
│   ├── kubeadmin-password
│   └── kubeconfig
├── bootstrap.ign
├── master.ign
├── metadata.json
└── worker.ign

Creating Fedora CoreOS (FCOS) machines

Before you install a cluster on bare metal infrastructure that you provision, you must create FCOS machines for it to use. To create the machines, follow either the steps to use an ISO image or network PXE booting.

There are several methods of configuring FCOS during ISO and PXE installations. These include:

Kernel arguments: For a PXE install, you can APPEND arguments to the kernel of the live installer. For an ISO install, you can interrupt the live installation boot process to add kernel arguments. In both cases, you can use special coreos.inst.* arguments to direct the live installer, as well as standard installation boot arguments for turning standard kernel services on or off.
Ignition configs: You must generate an OKD Ignition config file (*.ign) for the type of node you are installing (worker, control plane, or bootstrap). You pass the location of the Ignition config to the installed system so that it takes effect on first boot. In special cases, you can create a separate, limited Ignition config to pass to the live system. That Ignition config could do a certain set of tasks, such as reporting success to a provisioning system after completing installation. This special Ignition config is consumed by the installer and should not be used to include the standard worker and master Ignition configs.
coreos-installer: You can boot the live ISO installer to a shell prompt, which allows you to prepare the permanent system in a variety of ways before first boot. In particular, you can run the coreos-installer command to identify various artifacts to include, work with disk partitions, and set up networking. In some cases, you can configure features on the live system and copy them to the installed system.

Whether to use an ISO or PXE install depends on your situation. A PXE install requires an available DHCP service and more preparation, but can make the installation process more automated. An ISO install is a more manual process and can be inconvenient if you are setting up more than a few machines.

As of OKD 4.6, the FCOS ISO and other installation artifacts provide support for installation on disks with 4K sectors.

Creating Fedora CoreOS (FCOS) machines using an ISO image

Before you install a cluster on infrastructure that you provision, you must create FCOS machines for it to use. You can use an ISO image to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Have access to an HTTP server that can be accessed from your computer, and from the machines that you create.

Procedure

Upload the control plane, compute, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Obtain the FCOS images from the FCOS Downloads page
Use the ISO to start the FCOS installation. Use one of the following installation options:
- Burn the ISO image to a disk and boot it directly.
- Use ISO redirection via a LOM interface.
Boot the ISO image. You can interrupt the installation boot process to add kernel arguments. However, for this ISO procedure you should use the coreos-installer command instead of adding kernel arguments. If you run the live installer without options or interruption, the installer boots up to a shell prompt on the live system, ready for you to install FCOS to disk.
Review the Advanced FCOS installation reference section for different ways of configuring features, such as networking and disk partitions, before running the coreos-installer.
Run the coreos-installer command. At a minimum, you must identify the Ignition config file location for your node type, and the location of the disk you are installing to. Here is an example:
```
$ coreos-installer install \
     --ignition-url=https://host/worker.ign /dev/sda
```
After FCOS installs, the system reboots. During the system reboot, it applies the Ignition config file that you specified.

Continue to create the other machines for your cluster.

You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

Creating Fedora CoreOS (FCOS) machines by PXE or iPXE booting

Before you install a cluster that uses manually-provisioned FCOS nodes, such as bare metal, you must create FCOS machines for it to use. You can use PXE or iPXE booting to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Configure suitable PXE or iPXE infrastructure.
Have access to an HTTP server that you can access from your computer.

Procedure

Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.

You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.

Obtain the FCOS kernel, initramfs and rootfs files from the FCOS Downloads page
Upload the rootfs, kernel, and initramfs files to your HTTP server.

If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Configure the network boot infrastructure so that the machines boot from their local disks after FCOS is installed on them.

Configure PXE or iPXE installation for the FCOS images.

Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:

For PXE:

DEFAULT pxeboot
TIMEOUT 20
PROMPT 0
LABEL pxeboot
    KERNEL http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> (1)
    APPEND initrd=http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign (2) (3)

1	Specify the location of the live `kernel` file that you uploaded to your HTTP server. The URL must be HTTP, TFTP, or FTP; HTTPS and NFS are not supported.
2	If you use multiple NICs, specify a single interface in the `ip` option. For example, to use DHCP on a NIC that is named `eno1`, set `ip=eno1:dhcp`.
3	Specify locations of the FCOS files that you uploaded to your HTTP server. The `initrd` parameter value is the location of the `initramfs` file, the `coreos.live.rootfs_url` parameter value is the location of the `rootfs` file, and the `coreos.inst.ignition_url` parameter value is the location of the bootstrap Ignition config file. You can also add more kernel arguments to the `APPEND` line to configure networking or other boot options.

For iPXE:

kernel  http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign (1) (2)
initrd http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img
boot

1 Specify locations of the FCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd parameter value is the location of the initramfs file. The coreos.live.rootfs_url parameter value is the location of the rootfs file, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.

2 If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.

Continue to create the machines for your cluster.

Advanced Fedora CoreOS (FCOS) installation configuration

A key benefit for manually provisioning the Fedora CoreOS (FCOS) nodes for OKD is to be able to do configuration that is not available through default OKD installation methods. This section describes some of the configurations that you can do using techniques that include:

Passing kernel arguments to the live installer
Running coreos-installer manually from the live system
Embedding Ignition configs in an ISO

The advanced configuration topics for manual Fedora CoreOS (FCOS) installations detailed in this section relate to disk partitioning, networking, and using Ignition configs in different ways.

Using advanced networking options for PXE and ISO installations

Networking for OKD nodes uses DHCP by default to gather all necessary configuration settings. To set up static IP addresses or configure special settings, such as bonding, you can do one of the following:

Pass special kernel parameters when you boot the live installer.
Use a machine config to copy networking files to the installed system.
Configure networking from a live installer shell prompt, then copy those settings to the installed system so that they take effect when the installed system first boots.

To configure a PXE or iPXE installation, use one of the following options:

See the "Advanced RHCOS installation reference" tables.
Use a machine config to copy networking files to the installed system.

To configure an ISO installation, use the following procedure.

Procedure

Boot the ISO installer.
From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcli or nmtui.
Run the coreos-installer command to install the system, adding the --copy-network option to copy networking configuration. For example:
```
$ coreos-installer install --copy-network \
     --ignition-url=http://host/worker.ign /dev/sda
```
Reboot into the installed system.

Disk partitioning

In most cases, data partitions are originally created by installing FCOS, rather than by installing another operating system. In such cases, the OKD installer should be allowed to configure your disk partitions.

However, there are two cases where you might want to intervene to override the default partitioning when installing an OKD node:

Create separate partitions: For greenfield installations on an empty disk, you might want to add separate storage to a partition. This is officially supported for making /var or a subdirectory of /var, such as /var/lib/etcd, a separate partition, but not both.

Kubernetes supports only two filesystem partitions. If you add more than one partition to the original configuration, Kubernetes cannot monitor all of them.
Retain existing partitions: For a brownfield installation where you are reinstalling OKD on an existing node and want to retain data partitions installed from your previous operating system, there are both boot arguments and options to coreos-installer that allow you to retain existing data partitions.

Creating a separate `/var` partition

In general, disk partitioning for OKD should be left to the installer. However, there are cases where you might want to create separate partitions in a part of the filesystem that you expect to grow.

OKD supports the addition of a single partition to attach storage to either the /var partition or a subdirectory of /var. For example:

/var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system.
/var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage.
/var: Holds data that you might want to keep separate for purposes such as auditing.

Storing the contents of a /var directory separately makes it easier to grow storage for those areas as needed and reinstall OKD at a later date and keep that data intact. With this method, you will not have to pull all your containers again, nor will you have to copy massive log files when you update systems.

Because /var must be in place before a fresh installation of Fedora CoreOS (FCOS), the following procedure sets up the separate /var partition by creating a machine config that is inserted during the openshift-install preparation phases of an OKD installation.

Procedure

Create a directory to hold the OKD installation files:
```
$ mkdir $HOME/clusterconfig
```

Run openshift-install to create a set of files in the manifest and openshift subdirectories. Answer the system questions as you are prompted:

$ openshift-install create manifests --dir $HOME/clusterconfig
? SSH Public Key ...
$ ls $HOME/clusterconfig/openshift/
99_kubeadmin-password-secret.yaml
99_openshift-cluster-api_master-machines-0.yaml
99_openshift-cluster-api_master-machines-1.yaml
99_openshift-cluster-api_master-machines-2.yaml
...

Create a MachineConfig object and add it to a file in the openshift directory. For example, name the file 98-var-partition.yaml, change the disk device name to the name of the storage device on the worker systems, and set the storage size as appropriate. This attaches storage to a separate /var directory.

apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: worker
  name: 98-var-partition
spec:
  config:
    ignition:
      version: 3.1.0
    storage:
      disks:
      - device: /dev/<device_name> (1)
        partitions:
        - sizeMiB: <partition_size>
          startMiB: <partition_start_offset> (2)
          label: var
      filesystems:
        - path: /var
          device: /dev/disk/by-partlabel/var
          format: xfs
    systemd:
      units:
        - name: var.mount
          enabled: true
          contents: |
            [Unit]
            Before=local-fs.target
            [Mount]
            Where=/var
            What=/dev/disk/by-partlabel/var
            [Install]
            WantedBy=local-fs.target

The storage device name of the disk that you want to partition.

When adding a data partition to the boot disk, a minimum value of 25000 mebibytes is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of FCOS might overwrite the beginning of the data partition.

Run openshift-install again to create Ignition configs from a set of files in the manifest and openshift subdirectories:

$ openshift-install create ignition-configs --dir $HOME/clusterconfig
$ ls $HOME/clusterconfig/
auth  bootstrap.ign  master.ign  metadata.json  worker.ign

Now you can use the Ignition config files as input to the ISO or PXE manual installation procedures to install Fedora CoreOS (FCOS) systems.

Retaining existing partitions

For an ISO installation, you can add options to the coreos-installer command line that causes the installer to maintain one or more existing partitions. For a PXE installation, you can APPEND coreos.inst.* options to preserve partitions.

Saved partitions might be partitions from an existing OKD system that has data partitions that you want to keep. Here are a few tips:

If you save existing partitions, and those partitions do not leave enough space for FCOS, installation will fail without damaging the saved partitions.
Identify the disk partitions you want to keep either by partition label or by number.

For an ISO installation

This example preserves any partition in which the partition label begins with data (data*):

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partlabel 'data*' /dev/sda

The following example illustrates running the coreos-installer in a way that preserves the sixth (6) partition on the disk:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partindex 6 /dev/sda

This example preserves partitions 5 and higher:

# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign
        --save-partindex 5- /dev/sda

In the previous examples where partition saving is used, coreos-installer recreates the partition immediately.

For a PXE installation

This APPEND option preserves any partition in which the partition label begins with 'data' ('data*'):

coreos.inst.save_partlabel=data*

This APPEND option preserves partitions 5 and higher:

coreos.inst.save_partindex=5-

This APPEND option preserves partition 6:

coreos.inst.save_partindex=6

Identifying Ignition configs

When doing an FCOS manual installation, there are two types of Ignition configs that you can provide, with different reasons for providing each one:

Permanent install Ignition config: Every manual FCOS installation needs to pass one of the Ignition config files generated by openshift-installer, such as bootstrap.ign, master.ign and worker.ign, to carry out the installation.

It is not recommended to modify these files.

For PXE installations, you pass the Ignition configs on the APPEND line using the coreos.inst.ignition_url= option. For ISO installations, after the ISO boots to the shell prompt, you identify the Ignition config on the coreos-installer command line with the --ignition-url= option. In both cases, only HTTP and HTTPS protocols are supported.
Live install Ignition config: This type must be created manually and should be avoided if possible, as it is not supported by Red Hat. With this method, the Ignition config passes to the live install medium, runs immediately upon booting, and performs setup tasks before and/or after the FCOS system installs to disk. This method should only be used for performing tasks that must be performed once and not applied again later, such as with advanced partitioning that cannot be done using a machine config.

For PXE or ISO boots, you can create the Ignition config and APPEND the ignition.config.url= option to identify the location of the Ignition config. You also need to append ignition.firstboot ignition.platform.id=metal or the ignition.config.url option will be ignored.

Embedding an Ignition config in the FCOS ISO

You can embed a live install Ignition config directly in an FCOS ISO image. When the ISO image is booted, the embedded config will be applied automatically.

This type of configuration must be created manually and should be avoided if possible, as it is not supported by Red Hat.

Procedure

Download the coreos-installer binary from the following image mirror page: https://mirror.openshift.com/pub/openshift-v4/clients/coreos-installer/latest/.
Retrieve the FCOS ISO image and the Ignition config file, and copy them into an accessible directory, such as /mnt:
```
# cp rhcos-<version>-live.x86_64.iso live.ign /mnt/
# chmod 644 /mnt/rhcos-<version>-live.x86_64.iso
```
Run the following command to embed the Ignition config into the ISO:
```
# ./coreos-installer iso ignition embed -i /mnt/live.ign \
     /mnt/rhcos-<version>-live.x86_64.iso
```
You can now use that ISO to install FCOS using the specified live install Ignition config.

Using coreos-installer iso ignition embed to embed a file generated by openshift-installer, such as bootstrap.ign, master.ign and worker.ign, is unsupported and not recommended.

To show the contents of the embedded Ignition config and direct it into a file, run:

# ./coreos-installer iso ignition show /mnt/rhcos-<version>-live.x86_64.iso > mylive.ign

# diff -s live.ign mylive.ign

Example output

Files live.ign and mylive.ign are identical

To remove the Ignition config and return the ISO to its pristine state so you can reuse it, run:
```
# ./coreos-installer iso ignition remove /mnt/rhcos-<version>-live.x86_64.iso
```
You can now embed another Ignition config into the ISO or use the ISO in its pristine state.

Advanced FCOS installation reference

This section illustrates the networking configuration and other advanced options that allow you to modify the Fedora CoreOS (FCOS) manual installation process. The following tables describe the kernel arguments and command-line options you can use with the FCOS live installer and the coreos-installer command.

Routing and bonding options at FCOS boot prompt

If you install FCOS from an ISO image, you can add kernel arguments manually when you boot that image to configure the node’s networking. If no networking arguments are used, the installation defaults to using DHCP.

When adding networking arguments, you must also add the rd.neednet=1 kernel argument.

The following table describes how to use ip=, nameserver=, and bond= kernel arguments for live ISO installs.

Table 6. Routing and bonding options for ISO
Description	Examples
To configure an IP address, either use DHCP (`ip=dhcp`) or set an individual static IP address (`ip=<host_ip>`). If setting a static IP, you must then identify the DNS server IP address (`nameserver=<dns_ip>`) on each node. This example sets: The node’s IP address to `10.10.10.2` The gateway address to `10.10.10.254` The netmask to `255.255.255.0` The hostname to `core0.example.com` The DNS server address to `4.4.4.41`	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none nameserver=4.4.4.41
Specify multiple network interfaces by specifying multiple `ip=` entries.	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can combine DHCP and static IP configurations on systems with multiple network interfaces.	ip=enp1s0:dhcp ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can provide multiple DNS servers by adding a `nameserver=` entry for each server.	nameserver=1.1.1.1 nameserver=8.8.8.8
Optional: Bonding multiple network interfaces to a single interface is supported using the `bond=` option. In these two examples: The syntax for configuring a bonded interface is: `bond=name[:network_interfaces][:options]` name is the bonding device name (`bond0`), network_interfaces represents a comma-separated list of physical (ethernet) interfaces (`em1,em2`), and options is a comma-separated list of bonding options. Enter `modinfo bonding` to see available options. When you create a bonded interface using `bond=`, you must specify how the IP address is assigned and other information for the bonded interface.	To configure the bonded interface to use DHCP, set the bond’s IP address to `dhcp`. For example: bond=bond0:em1,em2:mode=active-backup ip=bond0:dhcp To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: bond=bond0:em1,em2:mode=active-backup ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none

`coreos.inst` boot options for ISO or PXE install

While you can pass most standard boot arguments to the live installer, there are several arguments that are specific to the FCOS live installer.

For ISO, these options can be added by interrupting the boot at the bootloader menu.
For PXE or iPXE, these options must be added to the APPEND line before starting the PXE kernel.

The following table shows the FCOS live installer boot options for ISO and PXE installs.

Table 7. `coreos.inst` boot options
Argument	Description
`coreos.inst.install_dev`	Required. The block device on the system to install to. It is recommended to use the full path, such as `/dev/sda`, although `sda` is allowed.
`coreos.inst.ignition_url`	Optional: The URL of the Ignition config to embed into the installed system. If no URL is specified, no Ignition config is embedded. Only HTTP and HTTPS protocols are supported.
`coreos.inst.save_partlabel`	Optional: Comma-separated labels of partitions to preserve during the install. Glob-style wildcards are permitted. The specified partitions do not need to exist.
`coreos.inst.save_partindex`	Optional: Comma-separated indexes of partitions to preserve during the install. Ranges `m-n` are permitted, and either `m` or `n` can be omitted. The specified partitions do not need to exist.
`coreos.inst.insecure`	Optional: Permits the OS image that is specified by `coreos.inst.image_url` to be unsigned.
`coreos.inst.image_url`	Optional: Download and install the specified FCOS image. This argument should not be used in production environments and is intended for debugging purposes only. While this argument can be used to install a version of FCOS that does not match the live media, it is recommended that you instead use the media that matches the version you want to install. If you are using `coreos.inst.image_url`, you must also use `coreos.inst.insecure`. This is because the bare-metal media are not GPG-signed for OKD. Only HTTP and HTTPS protocols are supported.
`coreos.inst.skip_reboot`	Optional: The system will not reboot after installing. Once the install finishes, you will receive a prompt that allows you to inspect what is happening during installation. This argument should not be used in production environments and is intended for debugging purposes only.
`coreos.inst.platform_id`	Optional: The Ignition platform ID of the platform the FCOS image is being installed on. Default is `metal`. This option determines whether or not to request an Ignition config from the cloud provider, such as VMware. For example: `coreos.inst.platform_id=vmware`.
`ignition.config.url`	Optional: The URL of the Ignition config for the live boot. For example, this can be used to customize how `coreos-installer` is invoked, or to run code before or after the installation. This is different from `coreos.inst.ignition_url`, which is the Ignition config for the installed system.

`coreos-installer` options for ISO install

You can also install FCOS by invoking the coreos-installer command directly from the command line. The kernel arguments in the previous table provide a shortcut for automatically invoking coreos-installer at boot time, but you can pass similar arguments directly to coreos-installer when running it from a shell prompt.

The following table shows the options and subcommands you can pass to the coreos-installer command during a live install.

Table 8. `coreos-installer` command-line options, arguments, and subcommands
Command-line options
Option	Description
`-u`, `--image-url <url>`	Specify the image URL manually.
`-i,` `--ignition-file <path>`	Embed an Ignition config from a file.
`I`, `--ignition-url <URL>`	Embed an Ignition config from a URL.
`--ignition-hash <digest>`	Digest `type-value` of the Ignition config.
`-p`, `--platform <name>`	Override the Ignition platform ID for the installed system.
`--append-karg <arg>…`	Append a default kernel argument to the installed system.
`--delete-karg <arg>…`	Delete a default kernel argument from the installed system.
`-n`, `--copy-network`	Copy the network configuration from the install environment.
`--network-dir <path>`	For use with `-n`. Default is `/etc/NetworkManager/system-connections/`.
`--save-partlabel <lx>..`	Save partitions with this label glob.
`--save-partindex <id>…`	Save partitions with this number or range.
`--insecure`	Skip signature verification.
`--insecure-ignition`	Allow Ignition URL without HTTPS or hash.
`--architecture <name>`	Target CPU architecture. Default is `x86_64`.
`--preserve-on-error`	Do not clear partition table on error.
`-h`, `--help`	Print help information.
`-f`, `--image-file <path>`	Specify a local image file manually. Used for debugging.

Command-line argument
Argument	Description
`<device>`	The destination device.

coreos-installer embedded Ignition commands
Command	Description
`$ coreos-installer iso ignition embed <options> --ignition-file <file_path> <ISO_image>`	Embed an Ignition config in an ISO image.
`coreos-installer iso ignition show <options> <ISO_image>`	Show the embedded Ignition config from an ISO image.
`coreos-installer iso ignition remove <options> <ISO_image>`	Remove the embedded Ignition config from an ISO image.

coreos-installer ISO Ignition options
Option	Description
`-f`, `--force`	Overwrite an existing Ignition config.
`-i`, `--ignition-file <path>`	The Ignition config to be used. Default is `stdin`.
`-o`, `--output <path>`	Write the ISO to a new output file.
`-h`, `--help`	Print help information.

coreos-installer PXE Ignition commands
Command	Description
Note that not all of these options are accepted by all subcommands.
`coreos-installer pxe ignition wrap <options>`	Wrap an Ignition config in an image.
`coreos-installer pxe ignition unwrap <options> <image_name>`	Show the wrapped Ignition config in an image.

coreos-installer PXE Ignition options
Option	Description
Note that not all of these options are accepted by all subcommands.
`-i`, `--ignition-file <path>`	The Ignition config to be used. Default is `stdin`.
`-o,` `--output <path>`	Write the ISO to a new output file.
`-h`, `--help`	Print help information.

Updating the bootloader using bootupd

To update the bootloader by using bootupd, you must either install bootupd on FCOS machines manually or provide a machine config with the enabled systemd unit. Unlike grubby or other bootloader tools, bootupd does not manage kernel space configuration such as passing kernel arguments.

After you have installed bootupd, you can manage it remotely from the OKD cluster.

It is recommended that you use bootupd only on bare metal or virtualized hypervisor installations, such as for protection against the BootHole vulnerability.

Manual install method

You can manually install bootupd by using the bootctl command-line tool.

Inspect the system status:

# bootupctl status

Example output

Component EFI
  Installed: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64
  Update: At latest version

FCOS images created without bootupd installed on them require an explicit adoption phase.

If the system status is Adoptable, perform the adoption:
```
# bootupctl adopt-and-update
```
Example output
```
Updated: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64
```
If an update is available, apply the update so that the changes take effect on the next reboot:
```
# bootupctl update
```
Example output
```
Updated: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64
```

Machine config method

Another way to enable bootupd is by providing a machine config.

Provide a machine config file with the enabled systemd unit, as shown in the following example:

Example output

  variant: rhcos
  version: 1.1.0
  systemd:
    units:
      - name: custom-bootupd-auto.service
        enabled: true
        contents: |
          [Unit]
          Description=Bootupd automatic update

          [Service]
          ExecStart=/usr/bin/bootupctl update
          RemainAfterExit=yes

          [Install]
          WantedBy=multi-user.target

Creating the cluster

To create the OKD cluster, you wait for the bootstrap process to complete on the machines that you provisioned by using the Ignition config files that you generated with the installation program.

Prerequisites

Create the required infrastructure for the cluster.
You obtained the installation program and generated the Ignition config files for your cluster.
You used the Ignition config files to create FCOS machines for your cluster.
Your machines have direct Internet access or have an HTTP or HTTPS proxy available.

Procedure

Monitor the bootstrap process:

$ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ (1)
    --log-level=info (2)

1	For `<installation_directory>`, specify the path to the directory that you stored the installation files in.
2	To view different installation details, specify `warn`, `debug`, or `error` instead of `info`.

Example output

INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.20.0 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources

The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.

After bootstrap process is complete, remove the bootstrap machine from the load balancer.

You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the machine itself.

Logging in to the cluster by using the CLI

You can log in to your cluster as a default system user by exporting the cluster kubeconfig file. The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server. The file is specific to a cluster and is created during OKD installation.

Prerequisites

You deployed an OKD cluster.
You installed the oc CLI.

Procedure

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig (1)
```
1 For <installation_directory>, specify the path to the directory that you stored the installation files in.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

Approving the certificate signing requests for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.20.0
master-1  Ready     master  63m  v1.20.0
master-2  Ready     master  64m  v1.20.0
worker-0  NotReady  worker  76s  v1.20.0
worker-1  NotReady  worker  70s  v1.20.0

The output lists all of the machines that you created.

The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved.

Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
...

In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:

Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. After you approve the initial CSRs, the subsequent node client CSRs are automatically approved by the cluster kube-controller-manager.

For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the oc exec, oc rsh, and oc logs commands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the node-bootstrapper service account in the system:node or system:admin groups, and confirm the identity of the node.

To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> (1)
```
1 <csr_name> is the name of a CSR from the list of current CSRs.

To approve all pending CSRs, run the following command:

$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve

Some Operators might not become available until some CSRs are approved.

Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
...

If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:
- To approve them individually, run the following command for each valid CSR:
  $ oc adm certificate approve <csr_name> (1)
  1 <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
  $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve

After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

For more information on CSRs, see Certificate Signing Requests.

Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

Your control plane has initialized.

Procedure

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.7.0   True        False         False      3h56m
baremetal                                  4.7.0   True        False         False      29h
cloud-credential                           4.7.0   True        False         False      29h
cluster-autoscaler                         4.7.0   True        False         False      29h
config-operator                            4.7.0   True        False         False      6h39m
console                                    4.7.0   True        False         False      3h59m
csi-snapshot-controller                    4.7.0   True        False         False      4h12m
dns                                        4.7.0   True        False         False      4h15m
etcd                                       4.7.0   True        False         False      29h
image-registry                             4.7.0   True        False         False      3h59m
ingress                                    4.7.0   True        False         False      4h30m
insights                                   4.7.0   True        False         False      29h
kube-apiserver                             4.7.0   True        False         False      29h
kube-controller-manager                    4.7.0   True        False         False      29h
kube-scheduler                             4.7.0   True        False         False      29h
kube-storage-version-migrator              4.7.0   True        False         False      4h2m
machine-api                                4.7.0   True        False         False      29h
machine-approver                           4.7.0   True        False         False      6h34m
machine-config                             4.7.0   True        False         False      3h56m
marketplace                                4.7.0   True        False         False      4h2m
monitoring                                 4.7.0   True        False         False      6h31m
network                                    4.7.0   True        False         False      29h
node-tuning                                4.7.0   True        False         False      4h30m
openshift-apiserver                        4.7.0   True        False         False      3h56m
openshift-controller-manager               4.7.0   True        False         False      4h36m
openshift-samples                          4.7.0   True        False         False      4h30m
operator-lifecycle-manager                 4.7.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.7.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.7.0   True        False         False      3h59m
service-ca                                 4.7.0   True        False         False      29h
storage                                    4.7.0   True        False         False      4h30m

Configure the Operators that are not available.

Image registry removed during installation

On platforms that do not provide shareable object storage, the OpenShift Image Registry Operator bootstraps itself as Removed. This allows openshift-installer to complete installations on these platform types.

After installation, you must edit the Image Registry Operator configuration to switch the managementState from Removed to Managed.

The Prometheus console provides an ImageRegistryRemoved alert, for example:

"Image Registry has been removed. ImageStreamTags, BuildConfigs and DeploymentConfigs which reference ImageStreamTags may not work as expected. Please configure storage and update the config to Managed state by editing configs.imageregistry.operator.openshift.io."

Image registry storage configuration

The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.

Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

Configuring registry storage for bare metal and other manual installations

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites

Cluster administrator permissions.
A cluster that uses manually-provisioned Fedora CoreOS (FCOS) nodes, such as bare metal.

Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.

OKD supports ReadWriteOnce access for image registry storage when you have only one replica. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.

Must have 100Gi capacity.

Procedure

To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.

When using shared storage, review your security settings to prevent outside access.
Verify that you do not have a registry pod:
```
$ oc get pod -n openshift-image-registry
```
If the storage type is emptyDIR, the replica number cannot be greater than 1.
Check the registry configuration:
```
$ oc edit configs.imageregistry.operator.openshift.io
```
Example output
```
storage:
  pvc:
    claim:
```
Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.
Check the clusteroperator status:
```
$ oc get clusteroperator image-registry
```
Ensure that your registry is set to managed to enable building and pushing of images.
- Run:
  $ oc edit configs.imageregistry/cluster
  Then, change the line
  managementState: Removed
  to
  managementState: Managed

Configuring storage for the image registry in non-production clusters

You must configure storage for the Image Registry Operator. For non-production clusters, you can set the image registry to an empty directory. If you do so, all images are lost if you restart the registry.

Procedure

To set the image registry storage to an empty directory:
```
$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'
```
Configure this option for only non-production clusters.

If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:
```
Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found
```
Wait a few minutes and run the command again.

Configuring block registry storage

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Block storage volumes are supported but not recommended for use with the image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica.

Procedure

To set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy and runs with only one (1) replica:
```
$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
```
Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.
Edit the registry configuration so that it references the correct PVC.

Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

Your control plane has initialized.
You have completed the initial Operator configuration.

Procedure

Confirm that all the cluster components are online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.7.0   True        False         False      3h56m
baremetal                                  4.7.0   True        False         False      29h
cloud-credential                           4.7.0   True        False         False      29h
cluster-autoscaler                         4.7.0   True        False         False      29h
config-operator                            4.7.0   True        False         False      6h39m
console                                    4.7.0   True        False         False      3h59m
csi-snapshot-controller                    4.7.0   True        False         False      4h12m
dns                                        4.7.0   True        False         False      4h15m
etcd                                       4.7.0   True        False         False      29h
image-registry                             4.7.0   True        False         False      3h59m
ingress                                    4.7.0   True        False         False      4h30m
insights                                   4.7.0   True        False         False      29h
kube-apiserver                             4.7.0   True        False         False      29h
kube-controller-manager                    4.7.0   True        False         False      29h
kube-scheduler                             4.7.0   True        False         False      29h
kube-storage-version-migrator              4.7.0   True        False         False      4h2m
machine-api                                4.7.0   True        False         False      29h
machine-approver                           4.7.0   True        False         False      6h34m
machine-config                             4.7.0   True        False         False      3h56m
marketplace                                4.7.0   True        False         False      4h2m
monitoring                                 4.7.0   True        False         False      6h31m
network                                    4.7.0   True        False         False      29h
node-tuning                                4.7.0   True        False         False      4h30m
openshift-apiserver                        4.7.0   True        False         False      3h56m
openshift-controller-manager               4.7.0   True        False         False      4h36m
openshift-samples                          4.7.0   True        False         False      4h30m
operator-lifecycle-manager                 4.7.0   True        False         False      29h
operator-lifecycle-manager-catalog         4.7.0   True        False         False      29h
operator-lifecycle-manager-packageserver   4.7.0   True        False         False      3h59m
service-ca                                 4.7.0   True        False         False      29h
storage                                    4.7.0   True        False         False      4h30m

When all of the cluster Operators are AVAILABLE, you can complete the installation.

Monitor for cluster completion:

$ ./openshift-install --dir=<installation_directory> wait-for install-complete (1)

1	For `<installation_directory>`, specify the path to the directory that you stored the installation files in.

Example output

INFO Waiting up to 30m0s for the cluster to initialize...

The command succeeds when the Cluster Version Operator finishes deploying the OKD cluster from Kubernetes API server.

Confirm that the Kubernetes API server is communicating with the pods.

To view a list of all pods, use the following command:

$ oc get pods --all-namespaces

Example output

NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
...

View the logs for a pod that is listed in the output of the previous command by using the following command:
```
$ oc logs <pod_name> -n <namespace> (1)
```
1 Specify the pod name and namespace, as shown in the output of the previous command.

If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

Next steps

Customize your cluster.
If necessary, you can opt out of remote health reporting.
Set up your registry and configure registry storage.

Prerequisites

Machine requirements for a cluster with user-provisioned infrastructure

Required machines

Network connectivity requirements

Minimum resource requirements

Certificate signing requests management

Creating the user-provisioned infrastructure

Networking requirements for user-provisioned infrastructure

Network topology requirements

Load balancers

User-provisioned DNS requirements

Generating an SSH private key and adding it to the agent

Obtaining the installation program

Installing the OpenShift CLI by downloading the binary

Installing the OpenShift CLI on Linux

Installing the OpenShift CLI on Windows

Installing the OpenShift CLI on macOS

Manually creating the installation configuration file

Sample install-config.yaml file for bare metal

Configuring the cluster-wide proxy during installation

Configuring a three-node cluster

Creating the Kubernetes manifest and Ignition config files

Creating Fedora CoreOS (FCOS) machines

Creating Fedora CoreOS (FCOS) machines using an ISO image

Creating Fedora CoreOS (FCOS) machines by PXE or iPXE booting

Advanced Fedora CoreOS (FCOS) installation configuration

Using advanced networking options for PXE and ISO installations

Disk partitioning

Creating a separate /var partition

Retaining existing partitions

Identifying Ignition configs

Embedding an Ignition config in the FCOS ISO

Advanced FCOS installation reference

Routing and bonding options at FCOS boot prompt

coreos.inst boot options for ISO or PXE install

coreos-installer options for ISO install

Updating the bootloader using bootupd

Creating the cluster

Logging in to the cluster by using the CLI

Approving the certificate signing requests for your machines

Initial Operator configuration

Image registry removed during installation

Image registry storage configuration

Configuring registry storage for bare metal and other manual installations

Configuring storage for the image registry in non-production clusters

Configuring block registry storage

Completing installation on user-provisioned infrastructure

Next steps

Sample `install-config.yaml` file for bare metal

Creating a separate `/var` partition

`coreos.inst` boot options for ISO or PXE install

`coreos-installer` options for ISO install