Chapter 3. Special Resource Operator

Procedure

1. Install the SRO in the openshift-operators namespace:

   1. Create the following Subscription CR and save the YAML in the sro-sub.yaml file:

      Example Subscription CR

      apiVersion: operators.coreos.com/v1alpha1
      kind: Subscription
      metadata:
        name: openshift-special-resource-operator
        namespace: openshift-operators
      spec:
        channel: "stable"
        installPlanApproval: Automatic
        name: openshift-special-resource-operator
        source: redhat-operators
        sourceNamespace: openshift-marketplace

   2. Create the subscription object by running the following command:

      $ oc create -f sro-sub.yaml

   3. Switch to the openshift-operators project:

      $ oc project openshift-operators

Procedure

1. Log in to the OpenShift Container Platform web console.

2. Install the Special Resource Operator:

   1. In the OpenShift Container Platform web console, click Operators OperatorHub.
   2. Choose Special Resource Operator from the list of available Operators, and then click Install.
   3. On the Install Operator page, select a specific namespace on the cluster, select the namespace created in the previous section, and then click Install.

1. Navigate to the Operators Installed Operators page.

2. Ensure that Special Resource Operator is listed in the openshift-operators project with a Status of InstallSucceeded.

   Note

   During installation, an Operator might display a Failed status. If the installation later succeeds with an InstallSucceeded message, you can ignore the Failed message.

3. If the Operator does not appear as installed, to troubleshoot further:

   1. Navigate to the Operators Installed Operators page and inspect the Operator Subscriptions and Install Plans tabs for any failure or errors under Status.
   2. Navigate to the Workloads Pods page and check the logs for pods in the openshift-operators project.
   Note

   The Node Feature Discovery (NFD) Operator is a dependency of the Special Resource Operator (SRO). If the NFD Operator is not installed before installing the SRO, the Operator Lifecycle Manager will automatically install the NFD Operator. However, the required Node Feature Discovery operand will not be deployed automatically. The Node Feature Discovery Operator documentation provides details about how to deploy NFD by using the NFD Operator.

Procedure

1. To create a simple-kmod SpecialResource object, define an image stream and build config to build the image, and a service account, role, role binding, and daemon set to run the container. The service account, role, and role binding are required to run the daemon set with the privileged security context so that the kernel module can be loaded.

   1. Create a templates directory, and change into it:

      $ mkdir -p chart/simple-kmod-0.0.1/templates

      $ cd chart/simple-kmod-0.0.1/templates

   2. Save this YAML template for the image stream and build config in the templates directory as 0000-buildconfig.yaml:

      apiVersion: image.openshift.io/v1
      kind: ImageStream
      metadata:
        labels:
          app: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}} 

      1

      
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}} 

      2

      
      spec: {}
      ---
      apiVersion: build.openshift.io/v1
      kind: BuildConfig
      metadata:
        labels:
          app: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverBuild}}  

      3

      
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverBuild}} 

      4

      
        annotations:
          specialresource.openshift.io/wait: "true"
          specialresource.openshift.io/driver-container-vendor: simple-kmod
          specialresource.openshift.io/kernel-affine: "true"
      spec:
        nodeSelector:
          node-role.kubernetes.io/worker: ""
        runPolicy: "Serial"
        triggers:
          - type: "ConfigChange"
          - type: "ImageChange"
        source:
          git:
            ref: {{.Values.specialresource.spec.driverContainer.source.git.ref}}
            uri: {{.Values.specialresource.spec.driverContainer.source.git.uri}}
          type: Git
        strategy:
          dockerStrategy:
            dockerfilePath: Dockerfile.SRO
            buildArgs:
              - name: "IMAGE"
                value: {{ .Values.driverToolkitImage  }}
              {{- range $arg := .Values.buildArgs }}
              - name: {{ $arg.name }}
                value: {{ $arg.value }}
              {{- end }}
              - name: KVER
                value: {{ .Values.kernelFullVersion }}
        output:
          to:
            kind: ImageStreamTag
            name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}:v{{.Values.kernelFullVersion}} 

      5

      1 2 3 4 5

      The templates such as {{.Values.specialresource.metadata.name}} are filled in by the SRO, based on fields in the SpecialResource CR and variables known to the Operator such as {{.Values.KernelFullVersion}}.

   3. Save the following YAML template for the RBAC resources and daemon set in the templates directory as 1000-driver-container.yaml:

      apiVersion: v1
      kind: ServiceAccount
      metadata:
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
      ---
      apiVersion: rbac.authorization.k8s.io/v1
      kind: Role
      metadata:
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
      rules:
      - apiGroups:
        - security.openshift.io
        resources:
        - securitycontextconstraints
        verbs:
        - use
        resourceNames:
        - privileged
      ---
      apiVersion: rbac.authorization.k8s.io/v1
      kind: RoleBinding
      metadata:
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
      roleRef:
        apiGroup: rbac.authorization.k8s.io
        kind: Role
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
      subjects:
      - kind: ServiceAccount
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
        namespace: {{.Values.specialresource.spec.namespace}}
      ---
      apiVersion: apps/v1
      kind: DaemonSet
      metadata:
        labels:
          app: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
        name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
        annotations:
          specialresource.openshift.io/wait: "true"
          specialresource.openshift.io/state: "driver-container"
          specialresource.openshift.io/driver-container-vendor: simple-kmod
          specialresource.openshift.io/kernel-affine: "true"
          specialresource.openshift.io/from-configmap: "true"
      spec:
        updateStrategy:
          type: OnDelete
        selector:
          matchLabels:
            app: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
        template:
          metadata:
            labels:
              app: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
          spec:
            priorityClassName: system-node-critical
            serviceAccount: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
            serviceAccountName: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
            containers:
            - image: image-registry.openshift-image-registry.svc:5000/{{.Values.specialresource.spec.namespace}}/{{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}:v{{.Values.kernelFullVersion}}
              name: {{.Values.specialresource.metadata.name}}-{{.Values.groupName.driverContainer}}
              imagePullPolicy: Always
              command: ["/sbin/init"]
              lifecycle:
                preStop:
                  exec:
                    command: ["/bin/sh", "-c", "systemctl stop kmods-via-containers@{{.Values.specialresource.metadata.name}}"]
              securityContext:
                privileged: true
            nodeSelector:
              node-role.kubernetes.io/worker: ""
              feature.node.kubernetes.io/kernel-version.full: "{{.Values.KernelFullVersion}}"

   4. Change into the chart/simple-kmod-0.0.1 directory:

      $ cd ..

   5. Save the following YAML for the chart as Chart.yaml in the chart/simple-kmod-0.0.1 directory:

      apiVersion: v2
      name: simple-kmod
      description: Simple kmod will deploy a simple kmod driver-container
      icon: https://avatars.githubusercontent.com/u/55542927
      type: application
      version: 0.0.1
      appVersion: 1.0.0

2. From the chart directory, create the chart using the helm package command:

   $ helm package simple-kmod-0.0.1/

   Example output

   Successfully packaged chart and saved it to: /data/<username>/git/<github_username>/special-resource-operator/yaml-for-docs/chart/simple-kmod-0.0.1/simple-kmod-0.0.1.tgz

3. Create a config map to store the chart files:

   1. Create a directory for the config map files:

      $ mkdir cm

   2. Copy the Helm chart into the cm directory:

      $ cp simple-kmod-0.0.1.tgz cm/simple-kmod-0.0.1.tgz

   3. Create an index file specifying the Helm repo that contains the Helm chart:

      $ helm repo index cm --url=cm://simple-kmod/simple-kmod-chart

   4. Create a namespace for the objects defined in the Helm chart:

      $ oc create namespace simple-kmod

   5. Create the config map object:

      $ oc create cm simple-kmod-chart --from-file=cm/index.yaml --from-file=cm/simple-kmod-0.0.1.tgz -n simple-kmod

4. Use the following SpecialResource manifest to deploy the simple-kmod object using the Helm chart that you created in the config map. Save this YAML as simple-kmod-configmap.yaml:

   apiVersion: sro.openshift.io/v1beta1
   kind: SpecialResource
   metadata:
     name: simple-kmod
   spec:
     #debug: true 

   1

   
     namespace: simple-kmod
     chart:
       name: simple-kmod
       version: 0.0.1
       repository:
         name: example
         url: cm://simple-kmod/simple-kmod-chart 

   2

   
     set:
       kind: Values
       apiVersion: sro.openshift.io/v1beta1
       kmodNames: ["simple-kmod", "simple-procfs-kmod"]
       buildArgs:
       - name: "KMODVER"
         value: "SRO"
     driverContainer:
       source:
         git:
           ref: "master"
           uri: "https://github.com/openshift-psap/kvc-simple-kmod.git"

   1

   Optional: Uncomment the #debug: true line to have the YAML files in the chart printed in full in the Operator logs and to verify that the logs are created and templated properly.

   2

   The spec.chart.repository.url field tells the SRO to look for the chart in a config map.

5. From a command line, create the SpecialResource file:

   $ oc create -f simple-kmod-configmap.yaml

1. Use oc get pods command to display the status of the build pods:

   $ oc get pods -n simple-kmod

   Example output

   NAME                                                  READY   STATUS      RESTARTS   AGE
   simple-kmod-driver-build-12813789169ac0ee-1-build     0/1     Completed   0          7m12s
   simple-kmod-driver-container-12813789169ac0ee-mjsnh   1/1     Running     0          8m2s
   simple-kmod-driver-container-12813789169ac0ee-qtkff   1/1     Running     0          8m2s

2. Use the oc logs command, along with the build pod name obtained from the oc get pods command above, to display the logs of the simple-kmod driver container image build:

   $ oc logs pod/simple-kmod-driver-build-12813789169ac0ee-1-build -n simple-kmod

3. To verify that the simple-kmod kernel modules are loaded, execute the lsmod command in one of the driver container pods that was returned from the oc get pods command above:

   $ oc exec -n simple-kmod -it pod/simple-kmod-driver-container-12813789169ac0ee-mjsnh -- lsmod | grep simple

   Example output

   simple_procfs_kmod     16384  0
   simple_kmod            16384  0