3.6. Allowing non-cluster administrators to install Operators

Procedure

1. Create a new namespace:

   $ cat <<EOF | oc create -f -
   apiVersion: v1
   kind: Namespace
   metadata:
     name: scoped
   EOF

2. Allocate permissions that you want the Operator(s) to be confined to. This involves creating a new service account, relevant role(s), and role binding(s).

   $ cat <<EOF | oc create -f -
   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: scoped
     namespace: scoped
   EOF

   The following example grants the service account permissions to do anything in the designated namespace for simplicity. In a production environment, you should create a more fine-grained set of permissions:

   $ cat <<EOF | oc create -f -
   apiVersion: rbac.authorization.k8s.io/v1
   kind: Role
   metadata:
     name: scoped
     namespace: scoped
   rules:
   - apiGroups: ["*"]
     resources: ["*"]
     verbs: ["*"]
   ---
   apiVersion: rbac.authorization.k8s.io/v1
   kind: RoleBinding
   metadata:
     name: scoped-bindings
     namespace: scoped
   roleRef:
     apiGroup: rbac.authorization.k8s.io
     kind: Role
     name: scoped
   subjects:
   - kind: ServiceAccount
     name: scoped
     namespace: scoped
   EOF

3. Create an OperatorGroup object in the designated namespace. This Operator group targets the designated namespace to ensure that its tenancy is confined to it.

   In addition, Operator groups allow a user to specify a service account. Specify the service account created in the previous step:

   $ cat <<EOF | oc create -f -
   apiVersion: operators.coreos.com/v1
   kind: OperatorGroup
   metadata:
     name: scoped
     namespace: scoped
   spec:
     serviceAccountName: scoped
     targetNamespaces:
     - scoped
   EOF

   Any Operator installed in the designated namespace is tied to this Operator group and therefore to the service account specified.

4. Create a Subscription object in the designated namespace to install an Operator:

   $ cat <<EOF | oc create -f -
   apiVersion: operators.coreos.com/v1alpha1
   kind: Subscription
   metadata:
     name: etcd
     namespace: scoped
   spec:
     channel: singlenamespace-alpha
     name: etcd
     source: <catalog_source_name> 1
     sourceNamespace: <catalog_source_namespace> 2
   EOF

   1

   Specify a catalog source that already exists in the designated namespace or one that is in the global catalog namespace.

   2

   Specify a namespace where the catalog source was created.

   Any Operator tied to this Operator group is confined to the permissions granted to the specified service account. If the Operator requests permissions that are outside the scope of the service account, the installation fails with relevant errors.

Procedure

1. Review the Subscription object. Its status has an object reference installPlanRef that points to the InstallPlan object that attempted to create the necessary [Cluster]Role[Binding] object(s) for the Operator:

   apiVersion: operators.coreos.com/v1
   kind: Subscription
   metadata:
     name: etcd
     namespace: scoped
   status:
     installPlanRef:
       apiVersion: operators.coreos.com/v1
       kind: InstallPlan
       name: install-4plp8
       namespace: scoped
       resourceVersion: "117359"
       uid: 2c1df80e-afea-11e9-bce3-5254009c9c23

2. Check the status of the InstallPlan object for any errors:

   apiVersion: operators.coreos.com/v1
   kind: InstallPlan
   status:
     conditions:
     - lastTransitionTime: "2019-07-26T21:13:10Z"
       lastUpdateTime: "2019-07-26T21:13:10Z"
       message: 'error creating clusterrole etcdoperator.v0.9.4-clusterwide-dsfx4: clusterroles.rbac.authorization.k8s.io
         is forbidden: User "system:serviceaccount:scoped:scoped" cannot create resource
         "clusterroles" in API group "rbac.authorization.k8s.io" at the cluster scope'
       reason: InstallComponentFailed
       status: "False"
       type: Installed
     phase: Failed

   The error message tells you:

   • The type of resource it failed to create, including the API group of the resource. In this case, it was clusterroles in the rbac.authorization.k8s.io group.
   • The name of the resource.
   • The type of error: is forbidden tells you that the user does not have enough permission to do the operation.
   • The name of the user who attempted to create or update the resource. In this case, it refers to the service account specified in the Operator group.

   • The scope of the operation: cluster scope or not.

     The user can add the missing permission to the service account and then iterate.

     注意

     Operator Lifecycle Manager (OLM) does not currently provide the complete list of errors on the first try.