Use separate Kubernetes namespaces per environment

Kubernetes deployments on new clusters will now have
a separate namespace per project environment, instead
of sharing a single namespace for the project.

Behaviour of existing clusters is unchanged.

All new functionality is controlled by the
:kubernetes_namespace_per_environment feature flag,
which is safe to enable/disable at any time.

4 files changed, 53 insertions, 0 deletions

diff --git a/db/migrate/20190712040400_add_environment_id_to_clusters_kubernetes_namespaces.rb b/db/migrate/20190712040400_add_environment_id_to_clusters_kubernetes_namespaces.rb
new file mode 100644
index 00000000000..5ab5a9ba2f8
--- /dev/null
+++ b/db/migrate/20190712040400_add_environment_id_to_clusters_kubernetes_namespaces.rb
@@ -0,0 +1,10 @@
+# frozen_string_literal: true
+
+class AddEnvironmentIdToClustersKubernetesNamespaces < ActiveRecord::Migration[5.1]
+  DOWNTIME = false
+
+  def change
+    add_reference :clusters_kubernetes_namespaces, :environment,
+      index: true, type: :bigint, foreign_key: { on_delete: :nullify }
+  end
+end
diff --git a/db/migrate/20190712040412_index_clusters_kubernetes_namespaces_on_environment_id.rb b/db/migrate/20190712040412_index_clusters_kubernetes_namespaces_on_environment_id.rb
new file mode 100644
index 00000000000..23082492091
--- /dev/null
+++ b/db/migrate/20190712040412_index_clusters_kubernetes_namespaces_on_environment_id.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+class IndexClustersKubernetesNamespacesOnEnvironmentId < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  INDEX_NAME = 'index_kubernetes_namespaces_on_cluster_project_environment_id'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :clusters_kubernetes_namespaces, [:cluster_id, :project_id, :environment_id], unique: true, name: INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_index :clusters_kubernetes_namespaces, name: INDEX_NAME
+  end
+end
diff --git a/db/migrate/20190712064021_add_namespace_per_environment_flag_to_clusters.rb b/db/migrate/20190712064021_add_namespace_per_environment_flag_to_clusters.rb
new file mode 100644
index 00000000000..4c8a0ab3def
--- /dev/null
+++ b/db/migrate/20190712064021_add_namespace_per_environment_flag_to_clusters.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddNamespacePerEnvironmentFlagToClusters < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    add_column_with_default :clusters, :namespace_per_environment, :boolean, default: false
+  end
+
+  def down
+    remove_column :clusters, :namespace_per_environment
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 8d5da4a07dd..828e36aa96c 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -880,6 +880,7 @@ ActiveRecord::Schema.define(version: 2019_08_02_235445) do
     t.integer "cluster_type", limit: 2, default: 3, null: false
     t.string "domain"
     t.boolean "managed", default: true, null: false
+    t.boolean "namespace_per_environment", default: false, null: false
     t.index ["enabled"], name: "index_clusters_on_enabled"
     t.index ["user_id"], name: "index_clusters_on_user_id"
   end
@@ -984,9 +985,12 @@ ActiveRecord::Schema.define(version: 2019_08_02_235445) do
     t.string "encrypted_service_account_token_iv"
     t.string "namespace", null: false
     t.string "service_account_name"
+    t.bigint "environment_id"
     t.index ["cluster_id", "namespace"], name: "kubernetes_namespaces_cluster_and_namespace", unique: true
+    t.index ["cluster_id", "project_id", "environment_id"], name: "index_kubernetes_namespaces_on_cluster_project_environment_id", unique: true
     t.index ["cluster_id"], name: "index_clusters_kubernetes_namespaces_on_cluster_id"
     t.index ["cluster_project_id"], name: "index_clusters_kubernetes_namespaces_on_cluster_project_id"
+    t.index ["environment_id"], name: "index_clusters_kubernetes_namespaces_on_environment_id"
     t.index ["project_id"], name: "index_clusters_kubernetes_namespaces_on_project_id"
   end
 
@@ -3711,6 +3715,7 @@ ActiveRecord::Schema.define(version: 2019_08_02_235445) do
   add_foreign_key "clusters_applications_runners", "clusters", on_delete: :cascade
   add_foreign_key "clusters_kubernetes_namespaces", "cluster_projects", on_delete: :nullify
   add_foreign_key "clusters_kubernetes_namespaces", "clusters", on_delete: :cascade
+  add_foreign_key "clusters_kubernetes_namespaces", "environments", on_delete: :nullify
   add_foreign_key "clusters_kubernetes_namespaces", "projects", on_delete: :nullify
   add_foreign_key "container_repositories", "projects"
   add_foreign_key "dependency_proxy_blobs", "namespaces", column: "group_id", name: "fk_db58bbc5d7", on_delete: :cascade