<p>I have an application that I can deploy to kubernetes (Google Kubernetes Engine) to which I'm trying to add Google's CDN. For this I'm adding a BackendConfig. But when my gitlab pipeline tries to apply it it returns the following error.</p>

<blockquote>
  <p>$ kubectl apply -f backend-config.yaml
  Error from server (Forbidden): error when retrieving current configuration of:
  Resource: "cloud.google.com/v1beta1, Resource=backendconfigs", GroupVersionKind: "cloud.google.com/v1beta1, Kind=BackendConfig"</p>
</blockquote>

<p>I have a strongly suspect that the account the pipeline is running under does not have enough privileges to access backend configs. Being new to k8s and gke I'm not sure how to fix this. Especially as I cannot find what permission is needed for this.</p>

<h2>Edit</h2>

<p>I added a <code>kubectl get backendconfigs</code> to my pipeline and that fails with the same error. Running it from my gcloud sdk environment the same command works.</p>

<p>Note the cluster is managed by Gitlab and using RBAC. My understanding is that gitlab creates service accounts per namespace in k8s with the <code>edit</code> role. </p>

<h2>Edit 2</h2>

<p>Added <code>ClusterRole</code> and <code>ClusterRoleBinding</code> based on Arghya's answer.</p>

<p>Output of $ kubectl get crd</p>

<pre><code>NAME                                           CREATED AT
backendconfigs.cloud.google.com                2020-01-09T15:37:27Z
capacityrequests.internal.autoscaling.k8s.io   2020-04-28T11:15:26Z
certificaterequests.cert-manager.io            2020-01-15T06:53:47Z
certificates.cert-manager.io                   2020-01-15T06:53:48Z
challenges.acme.cert-manager.io                2020-01-15T06:53:48Z
challenges.certmanager.k8s.io                  2020-01-09T15:47:01Z
clusterissuers.cert-manager.io                 2020-01-15T06:53:48Z
clusterissuers.certmanager.k8s.io              2020-01-09T15:47:01Z
issuers.cert-manager.io                        2020-01-15T06:53:48Z
issuers.certmanager.k8s.io                     2020-01-09T15:47:01Z
managedcertificates.networking.gke.io          2020-01-09T15:37:53Z
orders.acme.cert-manager.io                    2020-01-15T06:53:48Z
orders.certmanager.k8s.io                      2020-01-09T15:47:01Z
scalingpolicies.scalingpolicy.kope.io          2020-01-09T15:37:53Z
updateinfos.nodemanagement.gke.io              2020-01-09T15:37:53Z
</code></pre>

<p>Output of <code>kubectl describe crd backendconfigs.cloud.google.com</code></p>

<pre><code>Name:         backendconfigs.cloud.google.com
Namespace:    
Labels:       &lt;none&gt;
Annotations:  &lt;none&gt;
API Version:  apiextensions.k8s.io/v1beta1
Kind:         CustomResourceDefinition
Metadata:
  Creation Timestamp:  2020-01-09T15:37:27Z
  Generation:          1
  Resource Version:    198
  Self Link:           /apis/apiextensions.k8s.io/v1beta1/customresourcedefinitions/backendconfigs.cloud.google.com
  UID:                 f0bc780a-32f5-11ea-b7bd-42010aa40111
Spec:
  Conversion:
    Strategy:  None
  Group:       cloud.google.com
  Names:
    Kind:       BackendConfig
    List Kind:  BackendConfigList
    Plural:     backendconfigs
    Singular:   backendconfig
  Scope:        Namespaced
  Validation:
    Open APIV 3 Schema:
      Properties:
        API Version:
          Description:  APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#resources
          Type:         string
        Kind:
          Description:  Kind is a string value representing the REST resource this object represents. Servers may infer this from the endpoint the client submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds
          Type:         string
        Metadata:
          Type:  object
        Spec:
          Description:  BackendConfigSpec is the spec for a BackendConfig resource
          Properties:
            Cdn:
              Description:  CDNConfig contains configuration for CDN-enabled backends.
              Properties:
                Cache Policy:
                  Description:  CacheKeyPolicy contains configuration for how requests to a CDN-enabled backend are cached.
                  Properties:
                    Include Host:
                      Description:  If true, requests to different hosts will be cached separately.
                      Type:         boolean
                    Include Protocol:
                      Description:  If true, http and https requests will be cached separately.
                      Type:         boolean
                    Include Query String:
                      Description:  If true, query string parameters are included in the cache key according to QueryStringBlacklist and QueryStringWhitelist. If neither is set, the entire query string is included and if false the entire query string is excluded.
                      Type:         boolean
                    Query String Blacklist:
                      Description:  Names of query strint parameters to exclude from cache keys. All other parameters are included. Either specify QueryStringBlacklist or QueryStringWhitelist, but not both.
                      Items:
                        Type:  string
                      Type:    array
                    Query String Whitelist:
                      Description:  Names of query string parameters to include in cache keys. All other parameters are excluded. Either specify QueryStringBlacklist or QueryStringWhitelist, but not both.
                      Items:
                        Type:  string
                      Type:    array
                  Type:        object
                Enabled:
                  Type:  boolean
              Required:
                enabled
              Type:  object
            Connection Draining:
              Description:  ConnectionDrainingConfig contains configuration for connection draining. For now the draining timeout. May manage more settings in the future.
              Properties:
                Draining Timeout Sec:
                  Description:  Draining timeout in seconds.
                  Format:       int64
                  Type:         integer
              Type:             object
            Iap:
              Description:  IAPConfig contains configuration for IAP-enabled backends.
              Properties:
                Enabled:
                  Type:  boolean
                Oauthclient Credentials:
                  Description:  OAuthClientCredentials contains credentials for a single IAP-enabled backend.
                  Properties:
                    Client ID:
                      Description:  Direct reference to OAuth client id.
                      Type:         string
                    Client Secret:
                      Description:  Direct reference to OAuth client secret.
                      Type:         string
                    Secret Name:
                      Description:  The name of a k8s secret which stores the OAuth client id &amp; secret.
                      Type:         string
                  Required:
                    secretName
                  Type:  object
              Required:
                enabled
                oauthclientCredentials
              Type:  object
            Security Policy:
              Type:  object
            Session Affinity:
              Description:  SessionAffinityConfig contains configuration for stickyness parameters.
              Properties:
                Affinity Cookie Ttl Sec:
                  Format:  int64
                  Type:    integer
                Affinity Type:
                  Type:  string
              Type:      object
            Timeout Sec:
              Format:  int64
              Type:    integer
          Type:        object
        Status:
          Type:  object
  Version:       v1beta1
  Versions:
    Name:     v1beta1
    Served:   true
    Storage:  true
Status:
  Accepted Names:
    Kind:       BackendConfig
    List Kind:  BackendConfigList
    Plural:     backendconfigs
    Singular:   backendconfig
  Conditions:
    Last Transition Time:  2020-01-09T15:37:27Z
    Message:               no conflicts found
    Reason:                NoConflicts
    Status:                True
    Type:                  NamesAccepted
    Last Transition Time:  &lt;nil&gt;
    Message:               the initial names have been accepted
    Reason:                InitialNamesAccepted
    Status:                True
    Type:                  Established
  Stored Versions:
    v1beta1
Events:  &lt;none&gt;
</code></pre>

Eelke
<p>Create a ClusterRole and ClusterRoleBinding for service account <code>example-sa</code> in namespace <code>example-namespace</code></p>

<pre><code>apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: backendconfig-role
rules:
- apiGroups: ["cloud.google.com"]
  resources: ["backendconfigs"]
  verbs: ["get", "watch", "list", "create", "delete"]

---

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: backendconfig-rolebinding
subjects:
- kind: ServiceAccount
  name: example-sa 
  namespace: example-namespace
roleRef:
  kind: ClusterRole
  name: backendconfig-role
  apiGroup: rbac.authorization.k8s.io
</code></pre>

<p>To check the permission is applied</p>

<pre><code>kubectl auth can-i get backendconfigs --as=system:serviceaccount:example-namespace:example-sa -n example-namespace
</code></pre>
