Moves domain setting to Cluster setting

Changes domain field to be on the Cluster page show, removing it from
Auto DevOps setting. Also injects the new environment variable
KUBE_INGRESS_BASE_DOMAIN into kubernetes#predefined_variables.

Migration to move the information from ProjectAutoDevops#domain
to Clusters::Cluster#domain. As well as necessary modifications to qa
selectors

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/52363

7 files changed, 46 insertions, 22 deletions

diff --git a/app/controllers/clusters/clusters_controller.rb b/app/controllers/clusters/clusters_controller.rb
index b9717b97640..483842fe456 100644
--- a/app/controllers/clusters/clusters_controller.rb
+++ b/app/controllers/clusters/clusters_controller.rb
@@ -127,6 +127,7 @@ class Clusters::ClustersController < Clusters::BaseController
       params.require(:cluster).permit(
         :enabled,
         :environment_scope,
+        :domain,
         platform_kubernetes_attributes: [
           :namespace
         ]
@@ -136,6 +137,7 @@ class Clusters::ClustersController < Clusters::BaseController
         :enabled,
         :name,
         :environment_scope,
+        :domain,
         platform_kubernetes_attributes: [
           :api_url,
           :token,
diff --git a/app/helpers/auto_devops_helper.rb b/app/helpers/auto_devops_helper.rb
index 516c8a353ea..8628c90dc51 100644
--- a/app/helpers/auto_devops_helper.rb
+++ b/app/helpers/auto_devops_helper.rb
@@ -26,17 +26,6 @@ module AutoDevopsHelper
     end
   end
 
-  # rubocop: disable CodeReuse/ActiveRecord
-  def cluster_ingress_ip(project)
-    project
-      .cluster_ingresses
-      .where("external_ip is not null")
-      .limit(1)
-      .pluck(:external_ip)
-      .first
-  end
-  # rubocop: enable CodeReuse/ActiveRecord
-
   private
 
   def missing_auto_devops_domain?(project)
diff --git a/app/models/clusters/cluster.rb b/app/models/clusters/cluster.rb
index a2c48973fa5..2b677961df5 100644
--- a/app/models/clusters/cluster.rb
+++ b/app/models/clusters/cluster.rb
@@ -49,7 +49,7 @@ module Clusters
 
     validates :name, cluster_name: true
     validates :cluster_type, presence: true
-    validates :domain, allow_nil: true, hostname: { allow_numeric_hostname: true, require_valid_tld: true }
+    validates :domain, allow_blank: true, hostname: { allow_numeric_hostname: true, require_valid_tld: true }
 
     validate :restrict_modification, on: :update
     validate :no_groups, unless: :group_type?
@@ -65,6 +65,7 @@ module Clusters
     delegate :available?, to: :application_ingress, prefix: true, allow_nil: true
     delegate :available?, to: :application_prometheus, prefix: true, allow_nil: true
     delegate :available?, to: :application_knative, prefix: true, allow_nil: true
+    delegate :external_ip, to: :application_ingress, prefix: true, allow_nil: true
 
     enum cluster_type: {
       instance_type: 1,
@@ -193,8 +194,24 @@ module Clusters
       project_type?
     end
 
+    def has_domain?
+      domain.present? || instance_domain.present?
+    end
+
+    def predefined_variables
+      Gitlab::Ci::Variables::Collection.new.tap do |variables|
+        break variables unless has_domain?
+
+        variables.append(key: 'KUBE_INGRESS_BASE_DOMAIN', value: domain.presence || instance_domain)
+      end
+    end
+
     private
 
+    def instance_domain
+      Gitlab::CurrentSettings.auto_devops_domain
+    end
+
     def restrict_modification
       if provider&.on_creation?
         errors.add(:base, "cannot modify during creation")
diff --git a/app/models/clusters/platforms/kubernetes.rb b/app/models/clusters/platforms/kubernetes.rb
index 8f3424db295..c8969351ed9 100644
--- a/app/models/clusters/platforms/kubernetes.rb
+++ b/app/models/clusters/platforms/kubernetes.rb
@@ -98,6 +98,8 @@ module Clusters
               .append(key: 'KUBE_NAMESPACE', value: actual_namespace)
               .append(key: 'KUBECONFIG', value: kubeconfig, public: false, file: true)
           end
+
+          variables.concat(cluster.predefined_variables)
         end
       end
 
diff --git a/app/models/project_auto_devops.rb b/app/models/project_auto_devops.rb
index 2253ad7b543..d254ec158ca 100644
--- a/app/models/project_auto_devops.rb
+++ b/app/models/project_auto_devops.rb
@@ -24,6 +24,9 @@ class ProjectAutoDevops < ActiveRecord::Base
     domain.present? || instance_domain.present?
   end
 
+  # From 11.8, AUTO_DEVOPS_DOMAIN has been replaced by KUBE_INGRESS_BASE_DOMAIN.
+  # See Clusters::Cluster#predefined_variables and https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/24580
+  # for more info. Support for AUTO_DEVOPS_DOMAIN support will be dropped on 12.0.
   def predefined_variables
     Gitlab::Ci::Variables::Collection.new.tap do |variables|
       if has_domain?
diff --git a/app/views/clusters/clusters/_form.html.haml b/app/views/clusters/clusters/_form.html.haml
index 4c47e11927e..068f14364ec 100644
--- a/app/views/clusters/clusters/_form.html.haml
+++ b/app/views/clusters/clusters/_form.html.haml
@@ -20,12 +20,28 @@
       .form-text.text-muted= s_("ClusterIntegration|Choose which of your environments will use this cluster.")
     - else
       = text_field_tag :environment_scope, '*', class: 'col-md-6 form-control disabled', placeholder: s_('ClusterIntegration|Environment scope'), disabled: true
-      - environment_scope_url = 'https://docs.gitlab.com/ee/user/project/clusters/#setting-the-environment-scope-premium'
+      - environment_scope_url = 'https://docs.gitlab.com/ee/user/project/clusters/#base-domain'
       - environment_scope_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: environment_scope_url }
       .form-text.text-muted
         %code *
         = s_("ClusterIntegration| is the default environment scope for this cluster. This means that all jobs, regardless of their environment, will use this cluster. %{environment_scope_start}More information%{environment_scope_end}").html_safe % { environment_scope_start: environment_scope_start, environment_scope_end: '</a>'.html_safe }
 
+  .form-group
+    %h5= s_('ClusterIntegration|Base domain')
+    = field.text_field :domain, class: 'col-md-6 form-control js-select-on-focus'
+    .form-text.text-muted
+      - if @cluster.application_ingress_external_ip.present?
+        - auto_devops_url = 'https://docs.gitlab.com/ee/topics/autodevops/'
+        - auto_devops_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: auto_devops_url }
+        = s_('ClusterIntegration|Specifying a domain will allow you to use Auto Review Apps and Auto Deploy stages for %{auto_devops_start}Auto DevOps%{auto_devops_end}. The domain should have a wildcard DNS configured to the Ingress IP Address below.').html_safe % { auto_devops_start: auto_devops_start, auto_devops_end: '</a>'.html_safe }
+        = s_('ClusterIntegration|Alternatively')
+        %code #{@cluster.application_ingress_external_ip}.nip.io
+        - custom_domain_url = 'https://docs.gitlab.com/ee/user/project/clusters/#pointing-your-dns-at-the-cluster-ip'
+        - custom_domain_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: custom_domain_url }
+        = s_('ClusterIntegration| can be used instead of a custom domain. %{custom_domain_start}More information%{custom_domain_end}').html_safe % { custom_domain_start: custom_domain_start, custom_domain_end: '</a>'.html_safe }
+      - else
+        = s_('ClusterIntegration|Before setting a domain, you must first install Ingress on your cluster below.')
+
   - if can?(current_user, :update_cluster, @cluster)
     .form-group
       = field.submit _('Save changes'), class: 'btn btn-success'
diff --git a/app/views/projects/settings/ci_cd/_autodevops_form.html.haml b/app/views/projects/settings/ci_cd/_autodevops_form.html.haml
index 5ec5a06396e..c2bbcf8fcaf 100644
--- a/app/views/projects/settings/ci_cd/_autodevops_form.html.haml
+++ b/app/views/projects/settings/ci_cd/_autodevops_form.html.haml
@@ -21,15 +21,10 @@
                     = s_('CICD|The Auto DevOps pipeline will run if no alternative CI configuration file is found.')
                     = link_to _('More information'), help_page_path('topics/autodevops/index.md'), target: '_blank'
               .card-footer.js-extra-settings{ class: @project.auto_devops_enabled? || 'hidden' }
-                = form.label :domain do
-                  %strong= _('Domain')
-                = form.text_field :domain, class: 'form-control', placeholder: 'domain.com'
-                .form-text.text-muted
-                  = s_('CICD|You need to specify a domain if you want to use Auto Review Apps and Auto Deploy stages.')
-                  - if cluster_ingress_ip = cluster_ingress_ip(@project)
-                    = s_('%{nip_domain} can be used as an alternative to a custom domain.').html_safe % { nip_domain: "<code>#{cluster_ingress_ip}.nip.io</code>".html_safe }
-                  = link_to icon('question-circle'), help_page_path('topics/autodevops/index.md', anchor: 'auto-devops-base-domain'), target: '_blank'
-
+                %p.settings-message.text-center
+                  - kubernetes_cluster_link = 'https://docs.gitlab.com/ee/user/project/clusters/'
+                  - kubernetes_cluster_start = '<a href="%{url}" target="_blank" rel="noopener noreferrer">'.html_safe % { url: kubernetes_cluster_link }
+                  = s_('CICD|You must add a %{kubernetes_cluster_start}Kubernetes cluster integration%{kubernetes_cluster_end} to this project with a domain in order for your deployment strategy to work correctly.').html_safe % { kubernetes_cluster_start: kubernetes_cluster_start, kubernetes_cluster_end: '</a>'.html_safe }
                 %label.prepend-top-10
                   %strong= s_('CICD|Deployment strategy')
                 %p.settings-message.text-center