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.

2 files changed, 16 insertions, 2 deletions

diff --git a/spec/factories/clusters/clusters.rb b/spec/factories/clusters/clusters.rb
index b0d14b672f4..d294e6d055e 100644
--- a/spec/factories/clusters/clusters.rb
+++ b/spec/factories/clusters/clusters.rb
@@ -6,6 +6,7 @@ FactoryBot.define do
     name 'test-cluster'
     cluster_type :project_type
     managed true
+    namespace_per_environment true
 
     factory :cluster_for_group, traits: [:provided_by_gcp, :group]
 
@@ -29,6 +30,10 @@ FactoryBot.define do
       end
     end
 
+    trait :namespace_per_environment_disabled do
+      namespace_per_environment false
+    end
+
     trait :provided_by_user do
       provider_type :user
       platform_type :kubernetes
diff --git a/spec/factories/clusters/kubernetes_namespaces.rb b/spec/factories/clusters/kubernetes_namespaces.rb
index 042be7b4c4a..8d6ad1b9f79 100644
--- a/spec/factories/clusters/kubernetes_namespaces.rb
+++ b/spec/factories/clusters/kubernetes_namespaces.rb
@@ -5,12 +5,21 @@ FactoryBot.define do
     association :cluster, :project, :provided_by_gcp
 
     after(:build) do |kubernetes_namespace|
-      if kubernetes_namespace.cluster.project_type?
-        cluster_project = kubernetes_namespace.cluster.cluster_project
+      cluster = kubernetes_namespace.cluster
+
+      if cluster.project_type?
+        cluster_project = cluster.cluster_project
 
         kubernetes_namespace.project = cluster_project.project
         kubernetes_namespace.cluster_project = cluster_project
       end
+
+      kubernetes_namespace.namespace ||=
+        Gitlab::Kubernetes::DefaultNamespace.new(
+          cluster,
+          project: kubernetes_namespace.project
+        ).from_environment_slug(kubernetes_namespace.environment&.slug)
+      kubernetes_namespace.service_account_name ||= "#{kubernetes_namespace.namespace}-service-account"
     end
 
     trait :with_token do