To control access to an OKD cluster, a cluster administrator can configure user authentication and ensure only approved users access the cluster.
To interact with an OKD cluster, users must first authenticate to the OKD API in some way. You can authenticate by providing an OAuth access token or an X.509 client certificate in your requests to the OKD API.
If you do not present a valid access token or certificate, your request is unauthenticated and you receive an HTTP 401 error.
An administrator can configure authentication through the following tasks:
Configuring an identity provider: You can define any supported identity provider in OKD and add it to your cluster.
Configuring the internal OAuth server: The OKD control plane includes a built-in OAuth server that determines the user’s identity from the configured identity provider and creates an access token. You can configure the token duration and inactivity timeout.
When users send a request for an OAuth token, they must specify either a default or custom OAuth client that receives and uses the token.
Impersonating a system admin user: You can grant cluster administrator permissions to a user by impersonating a system admin user.
Authorization involves determining whether the identified user has permissions to perform the requested action.
You can also control access to an OKD cluster through projects and namespaces.
Along with controlling user access to a cluster, you can also control the actions a pod can perform and the resources it can access using security context constraints (SCCs).
You can manage authorization for OKD through the following tasks:
Creating a local role and assigning it to a user or group.
Creating a cluster-admin user: By default, your cluster has only one cluster administrator called
kubeadmin. You can create another cluster administrator. Before creating a cluster administrator, ensure that you have configured an identity provider.
After creating the cluster admin user, delete the existing kubeadmin user to improve cluster security.
Creating service accounts: Service accounts provide a flexible way to control API access without sharing a regular user’s credentials. A user can create and use a service account in applications and also as an OAuth client.
Scoping tokens: A scoped token is a token that identifies as a specific user who can perform only specific operations. You can create scoped tokens to delegate some of your permissions to another user or a service account.
Syncing LDAP groups: You can manage user groups in one place by syncing the groups stored in an LDAP server with the OKD user groups.