Red Hat OpenShift Container Platform

Approve the certificate signing requests for your machines

To allow newly added machines to join your Red Hat OpenShift Container Platform cluster, confirm that the cluster approves pending certificate signing requests (CSRs), or approve them yourself. Approve client requests first, then 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  v1.35.4
master-1  Ready     master  63m  v1.35.4
master-2  Ready     master  64m  v1.35.4
```
The output lists all of the machines that you created.

The preceding output might not include the compute 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:

You must approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates rotate, and more than two certificates are present for each node. You must approve all of these certificates. After you approve the client CSR, the kubelet creates a secondary CSR for the serving certificate, which requires manual approval. The machine-approver then automatically approves later serving certificate renewal requests if the kubelet requests a new certificate with the same parameters.

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 you do not approve a request, 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 node-bootstrapper service account in the system:node or system:admin groups submitted the CSR, 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>
```
where:

<csr_name>

Specifies 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. Each node submits two CSRs, so you might need to run the command to approve CSRs multiple times.

After you approve your client requests, 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>
  where:
  
  <csr_name>
  
  Specifies 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 you approve all client and server CSRs, 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  v1.35.4
master-1  Ready     master  73m  v1.35.4
master-2  Ready     master  74m  v1.35.4
worker-0  Ready     worker  11m  v1.35.4
worker-1  Ready     worker  11m  v1.35.4

You might need to wait a few minutes after approval of the server CSRs for the machines to reach the Ready status.