Migrate project level clusters with no Kubernetes namespace to unmanaged

These clusters were created before we introduced the
option to manage your own cluster, and not having a
Kubernetes namespace present means that we have tried
and failed to create one - and therefore we cannot manage
your cluster for you.

The 5 minute window should prevent a race condition
where a cluster has only just been created and we
haven't had a chance to create any resources for it
yet.

1 files changed, 48 insertions, 0 deletions

diff --git a/db/post_migrate/20190606163724_migrate_legacy_managed_clusters_to_unmanaged.rb b/db/post_migrate/20190606163724_migrate_legacy_managed_clusters_to_unmanaged.rb
new file mode 100644
index 00000000000..759ab939f7d
--- /dev/null
+++ b/db/post_migrate/20190606163724_migrate_legacy_managed_clusters_to_unmanaged.rb
@@ -0,0 +1,48 @@
+# 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 MigrateLegacyManagedClustersToUnmanaged < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  class Cluster < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'clusters'
+
+    has_many :kubernetes_namespaces, class_name: 'MigrateLegacyManagedClustersToUnmanaged::KubernetesNamespace'
+
+    scope :managed, -> { where(managed: true) }
+
+    enum cluster_type: {
+      instance_type: 1,
+      group_type: 2,
+      project_type: 3
+    }
+  end
+
+  class KubernetesNamespace < ActiveRecord::Base
+    self.table_name = 'clusters_kubernetes_namespaces'
+
+    belongs_to :cluster, class_name: 'MigrateLegacyManagedClustersToUnmanaged::Cluster'
+  end
+
+  def up
+    Cluster.managed
+      .project_type
+      .left_joins(:kubernetes_namespaces)
+      .where(clusters_kubernetes_namespaces: { cluster_id: nil })
+      .where('clusters.created_at < ?', 5.minutes.ago)
+      .each_batch do |batch|
+        batch.update_all(managed: false)
+      end
+  end
+
+  def down
+  end
+end