Include cluster domain into Project Cluster API

Domain was introduced on 11.8 and was not included on the
Project Cluster API. With this change user will be able to include
domain when adding and updating a cluster. Domain will also be included
on the GET calls.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/59441

changelogs/unreleased/59441-add-base-domain-to-cluster-api.yml

+---
+title: Add cluster domain to Project Cluster API
+merge_request: 26735
+author:
+type: other

doc/api/project_clusters.md

@@ -33,6 +33,7 @@ Example response:
   {
     "id":18,
     "name":"cluster-1",
+    "domain":"example.com",
     "created_at":"2019-01-02T20:18:12.563Z",
     "provider_type":"user",
     "platform_type":"kubernetes",
@@ -90,6 +91,7 @@ Example response:
 {
   "id":18,
   "name":"cluster-1",
+  "domain":"example.com",
   "created_at":"2019-01-02T20:18:12.563Z",
   "provider_type":"user",
   "platform_type":"kubernetes",
@@ -157,6 +159,7 @@ Parameters:
 | --------- | ---- | -------- | ----------- |
 | `id` | integer | yes | The ID of the project owned by the authenticated user |
 | `name` | String | yes | The name of the cluster |
+| `domain` | String | no | The [base domain](../user/project/clusters/index.md#base_domain) of the cluster |
 | `enabled` | Boolean | no | Determines if cluster is active or not, defaults to true |
 | `platform_kubernetes_attributes[api_url]` | String | yes | The URL to access the Kubernetes API |
 | `platform_kubernetes_attributes[token]` | String | yes | The token to authenticate against Kubernetes |
@@ -247,6 +250,7 @@ Parameters:
 | `id` | integer | yes | The ID of the project owned by the authenticated user |
 | `cluster_id` | integer | yes | The ID of the cluster |
 | `name` | String | no | The name of the cluster |
+| `domain` | String | no | The [base domain](../user/project/clusters/index.md#base_domain) of the cluster |
 | `platform_kubernetes_attributes[api_url]` | String | no | The URL to access the Kubernetes API |
 | `platform_kubernetes_attributes[token]` | String | no | The token to authenticate against Kubernetes |
 | `platform_kubernetes_attributes[ca_cert]` | String | no | TLS certificate (needed if API is using a self-signed TLS certificate |
@@ -262,7 +266,7 @@ Example request:
 ```bash
 curl --header 'Private-Token: <your_access_token>' https://gitlab.example.com/api/v4/projects/26/clusters/24 \
 -H "Content-Type:application/json" \
--X PUT --data '{"name":"new-cluster-name","api_url":"https://new-api-url.com"}'
+-X PUT --data '{"name":"new-cluster-name","domain":"new-domain.com","api_url":"https://new-api-url.com"}'
 ```
 
 Example response:
@@ -271,6 +275,7 @@ Example response:
 {
   "id":24,
   "name":"new-cluster-name",
+  "domain":"new-domain.com",
   "created_at":"2019-01-03T21:53:40.610Z",
   "provider_type":"user",
   "platform_type":"kubernetes",

lib/api/entities.rb

@@ -1588,7 +1588,7 @@ module API
     end
 
     class Cluster < Grape::Entity
-      expose :id, :name, :created_at
+      expose :id, :name, :created_at, :domain
       expose :provider_type, :platform_type, :environment_scope, :cluster_type
       expose :user, using: Entities::UserBasic
       expose :platform_kubernetes, using: Entities::Platform::Kubernetes

lib/api/project_clusters.rb

@@ -53,6 +53,7 @@ module API
       params do
         requires :name, type: String, desc: 'Cluster name'
         optional :enabled, type: Boolean, default: true, desc: 'Determines if cluster is active or not, defaults to true'
+        optional :domain, type: String, desc: 'Cluster base domain'
         requires :platform_kubernetes_attributes, type: Hash, desc: %q(Platform Kubernetes data) do
           requires :api_url, type: String, allow_blank: false, desc: 'URL to access the Kubernetes API'
           requires :token, type: String, desc: 'Token to authenticate against Kubernetes'
@@ -83,6 +84,7 @@ module API
       params do
         requires :cluster_id, type: Integer, desc: 'The cluster ID'
         optional :name, type: String, desc: 'Cluster name'
+        optional :domain, type: String, desc: 'Cluster base domain'
         optional :platform_kubernetes_attributes, type: Hash, desc: %q(Platform Kubernetes data) do
           optional :api_url, type: String, desc: 'URL to access the Kubernetes API'
           optional :token, type: String, desc: 'Token to authenticate against Kubernetes'

spec/requests/api/project_clusters_spec.rb

@@ -60,7 +60,7 @@ describe API::ProjectClusters do
     end
 
     let(:cluster) do
-      create(:cluster, :project, :provided_by_gcp,
+      create(:cluster, :project, :provided_by_gcp, :with_domain,
              platform_kubernetes: platform_kubernetes,
              user: current_user,
              projects: [project])
@@ -88,6 +88,7 @@ describe API::ProjectClusters do
         expect(json_response['platform_type']).to eq('kubernetes')
         expect(json_response['environment_scope']).to eq('*')
         expect(json_response['cluster_type']).to eq('project_type')
+        expect(json_response['domain']).to eq('example.com')
       end
 
       it 'returns project information' do
@@ -187,6 +188,7 @@ describe API::ProjectClusters do
     let(:cluster_params) do
       {
         name: 'test-cluster',
+        domain: 'domain.example.com',
         platform_kubernetes_attributes: platform_kubernetes_attributes
       }
     end
@@ -217,6 +219,7 @@ describe API::ProjectClusters do
           expect(cluster_result).to be_kubernetes
           expect(cluster_result.project).to eq(project)
           expect(cluster_result.name).to eq('test-cluster')
+          expect(cluster_result.domain).to eq('domain.example.com')
           expect(platform_kubernetes.rbac?).to be_truthy
           expect(platform_kubernetes.api_url).to eq(api_url)
           expect(platform_kubernetes.namespace).to eq(namespace)
@@ -294,6 +297,7 @@ describe API::ProjectClusters do
 
     let(:update_params) do
       {
+        domain: 'new-domain.com',
         platform_kubernetes_attributes: platform_kubernetes_attributes
       }
     end
@@ -330,6 +334,7 @@ describe API::ProjectClusters do
         end
 
         it 'should update cluster attributes' do
+          expect(cluster.domain).to eq('new-domain.com')
           expect(cluster.platform_kubernetes.namespace).to eq('new-namespace')
         end
       end
@@ -342,6 +347,7 @@ describe API::ProjectClusters do
         end
 
         it 'should not update cluster attributes' do
+          expect(cluster.domain).not_to eq('new_domain.com')
           expect(cluster.platform_kubernetes.namespace).not_to eq('invalid_namespace')
           expect(cluster.kubernetes_namespace.namespace).not_to eq('invalid_namespace')
         end