$ oc login -u kubeadmin -p <password> https://FQDN:6443
The default API server certificate is issued by an internal OKD cluster CA. Clients outside of the cluster will not be able to verify the API server’s certificate by default. This certificate can be replaced by one that is issued by a CA that clients trust.
The default API server certificate is issued by an internal OKD cluster CA. You can add one or more alternative certificates that the API server will return based on the fully qualified domain name (FQDN) requested by the client, for example when a reverse proxy or load balancer is used.
You must have a certificate for the FQDN and its corresponding private key. Each should be in a separate PEM format file.
The private key must be unencrypted. If your key is encrypted, decrypt it before importing it into OKD.
The certificate must include the subjectAltName
extension showing the FQDN.
The certificate file can contain one or more certificates in a chain. The certificate for the API server FQDN must be the first certificate in the file. It can then be followed with any intermediate certificates, and the file should end with the root CA certificate.
Do not provide a named certificate for the internal load balancer (host
name |
Login to the new API as the kubeadmin
user.
$ oc login -u kubeadmin -p <password> https://FQDN:6443
Get the kubeconfig
file.
$ oc config view --flatten > kubeconfig-newapi
Create a secret that contains the certificate chain and private key in the
openshift-config
namespace.
$ oc create secret tls <secret> \(1)
--cert=</path/to/cert.crt> \(2)
--key=</path/to/cert.key> \(3)
-n openshift-config
1 | <secret> is the name of the secret that will contain the certificate chain and private key. |
2 | </path/to/cert.crt> is the path to the certificate chain on your local file system. |
3 | </path/to/cert.key> is the path to the private key associated with this certificate. |
Update the API server to reference the created secret.
$ oc patch apiserver cluster \
--type=merge -p \
'{"spec":{"servingCerts": {"namedCertificates":
[{"names": ["<FQDN>"], (1)
"servingCertificate": {"name": "<secret>"}}]}}}' (2)
1 | Replace <FQDN> with the FQDN that the API server should provide the certificate for. |
2 | Replace <secret> with the name used for the secret in the previous step. |
Examine the apiserver/cluster
object and confirm the secret is now
referenced.
$ oc get apiserver cluster -o yaml
...
spec:
servingCerts:
namedCertificates:
- names:
- <FQDN>
servingCertificate:
name: <secret>
...
Check the kube-apiserver
operator, and verify that a new revision of the Kubernetes API server rolls out.
It may take a minute for the operator to detect the configuration change and trigger a new deployment.
While the new revision is rolling out, PROGRESSING
will report True
.
$ oc get clusteroperators kube-apiserver
Do not continue to the next step until PROGRESSING
is listed as False
, as shown in the following output:
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE
kube-apiserver 4.17.0 True False False 145m
If PROGRESSING
is showing True
, wait a few minutes and try again.
A new revision of the Kubernetes API server only rolls out if the API server named certificate is added for the first time. When the API server named certificate is renewed, a new revision of the Kubernetes API server does not roll out because the |