Chapter 7. Placing nodes in maintenance mode with Node Maintenance Operator

Procedure

1. In the Red Hat OpenShift web console, navigate to Operators OperatorHub.
2. Select the Node Maintenance Operator, then click Install.
3. Keep the default selection of Installation mode and namespace to ensure that the Operator will be installed to the openshift-workload-availability namespace.
4. Click Install.

1. Navigate to the Operators Installed Operators page.
2. Check that the Operator is installed in the openshift-workload-availability namespace and that its status is Succeeded.

1. Navigate to the Operators Installed Operators page and inspect the Status column for any errors or failures.
2. Navigate to the Operators Installed Operators Node Maintenance Operator Details page, and inspect the Conditions section for errors before pod creation.
3. Navigate to the Workloads Pods page, search for the Node Maintenance Operator pod in the installed namespace, and check the logs in the Logs tab.

Procedure

1. Create a Namespace CR for the Node Maintenance Operator:

   1. Define the Namespace CR and save the YAML file, for example, workload-availability-namespace.yaml:

      apiVersion: v1
      kind: Namespace
      metadata:
        name: openshift-workload-availability

   2. To create the Namespace CR, run the following command:

      $ oc create -f workload-availability-namespace.yaml

2. Create an OperatorGroup CR:

   1. Define the OperatorGroup CR and save the YAML file, for example, workload-availability-operator-group.yaml:

      apiVersion: operators.coreos.com/v1
      kind: OperatorGroup
      metadata:
        name: workload-availability-operator-group
        namespace: openshift-workload-availability

   2. To create the OperatorGroup CR, run the following command:

      $ oc create -f workload-availability-operator-group.yaml

3. Create a Subscription CR:

   1. Define the Subscription CR and save the YAML file, for example, node-maintenance-subscription.yaml:

      apiVersion: operators.coreos.com/v1alpha1
      kind: Subscription
      metadata:
        name: node-maintenance-operator
        namespace: openshift-workload-availability 

      1

      
      spec:
        channel: stable
        installPlanApproval: Automatic
        name: node-maintenance-operator
        source: redhat-operators
        sourceNamespace: openshift-marketplace
        package: node-maintenance-operator

      1

      Specify the Namespace where you want to install the Node Maintenance Operator.

      Important

      To install the Node Maintenance Operator in the openshift-workload-availability namespace, specify openshift-workload-availability in the Subscription CR.

   2. To create the Subscription CR, run the following command:

      $ oc create -f node-maintenance-subscription.yaml

Verification

1. Verify that the installation succeeded by inspecting the CSV resource:

   $ oc get csv -n openshift-workload-availability

   Example output

   NAME                               DISPLAY                     VERSION   REPLACES  PHASE
   node-maintenance-operator.v5.3.0   Node Maintenance Operator   5.3.0   node-maintenance-operator.v5.2.1            Succeeded

2. Verify that the Node Maintenance Operator is running:

   $ oc get deployment -n openshift-workload-availability

   Example output

   NAME                                           READY   UP-TO-DATE   AVAILABLE   AGE
   node-maintenance-operator-controller-manager   1/1     1            1           10d

Procedure

1. From the Administrator perspective in the web console, navigate to Operators Installed Operators.
2. Select the Node Maintenance Operator from the list of Operators.
3. In the Node Maintenance tab, click Create NodeMaintenance.
4. In the Create NodeMaintenance page, select the Form view or the YAML view to configure the NodeMaintenance CR.
5. To apply the NodeMaintenance CR that you have configured, click Create.

Procedure

1. Create the following NodeMaintenance CR, and save the file as nodemaintenance-cr.yaml:

   apiVersion: nodemaintenance.medik8s.io/v1beta1
   kind: NodeMaintenance
   metadata:
     name: nodemaintenance-cr  

   1

   
   spec:
     nodeName: node-1.example.com 

   2

   
     reason: "NIC replacement" 

   3

   1

   The name of the node maintenance CR.

   2

   The name of the node to be put into maintenance mode.

   3

   A plain text description of the reason for maintenance.

2. Apply the node maintenance CR by running the following command:

   $ oc apply -f nodemaintenance-cr.yaml

Verification

1. Check the progress of the maintenance task by running the following command:

   $ oc describe node <node-name>

   where <node-name> is the name of your node; for example, node-1.example.com

2. Check the example output:

   Events:
     Type     Reason                     Age                   From     Message
     ----     ------                     ----                  ----     -------
     Normal   NodeNotSchedulable         61m                   kubelet  Node node-1.example.com status is now: NodeNotSchedulable

Procedure

1. From the Administrator perspective in the web console, navigate to Operators Installed Operators.
2. Select the Node Maintenance Operator from the list of Operators.
3. In the Node Maintenance tab, select the NodeMaintenance CR that you want to delete.
4. Click the Options menu at the end of the node and select Delete NodeMaintenance.

Verification

1. In the Red Hat OpenShift console, click Compute Nodes.
2. Inspect the Status column of the node for which you deleted the NodeMaintenance CR and verify that its status is Ready.

Verification

1. Check the progress of the maintenance task by running the following command:

   $ oc describe node <node-name>

   where <node-name> is the name of your node; for example, node-1.example.com

2. Check the example output:

   Events:
     Type     Reason                  Age                   From     Message
     ----     ------                  ----                  ----     -------
     Normal   NodeSchedulable         2m                    kubelet  Node node-1.example.com status is now: NodeSchedulable

Procedure

1. From the Administrator perspective of the web console, click Compute Nodes.

2. You can set the node to maintenance from this screen, which makes it easier to perform actions on multiple nodes, or from the Node Details screen, where you can view comprehensive details of the selected node:

   • Click the Options menu at the end of the node and select Start Maintenance.
   • Click the node name to open the Node Details screen and click Actions Start Maintenance.
3. Click Start Maintenance in the confirmation window.

Procedure

1. From the Administrator perspective of the web console, click Compute Nodes.

2. You can resume the node from this screen, which makes it easier to perform actions on multiple nodes, or from the Node Details screen, where you can view comprehensive details of the selected node:

   • Click the Options menu at the end of the node and select Stop Maintenance.
   • Click the node name to open the Node Details screen and click Actions Stop Maintenance.
3. Click Stop Maintenance in the confirmation window.