Add a model for `fork_networks`

The fork network will keep track of the root project as long as it's
present.

2 files changed, 36 insertions, 0 deletions

diff --git a/db/migrate/20170928124105_create_fork_networks.rb b/db/migrate/20170928124105_create_fork_networks.rb
new file mode 100644
index 00000000000..ca906b953a3
--- /dev/null
+++ b/db/migrate/20170928124105_create_fork_networks.rb
@@ -0,0 +1,28 @@
+class CreateForkNetworks < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def up
+    create_table :fork_networks do |t|
+      t.references :root_project,
+                   references: :projects,
+                   index: { unique: true }
+
+      t.string :deleted_root_project_name
+    end
+
+    add_concurrent_foreign_key :fork_networks, :projects,
+                               column: :root_project_id,
+                               on_delete: :nullify
+  end
+
+  def down
+    if foreign_keys_for(:fork_networks, :root_project_id).any?
+      remove_foreign_key :fork_networks, column: :root_project_id
+    end
+    drop_table :fork_networks
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 25aa15b837f..d7e1a2c94fa 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -591,6 +591,13 @@ ActiveRecord::Schema.define(version: 20171006091000) do
 
   add_index "features", ["key"], name: "index_features_on_key", unique: true, using: :btree
 
+  create_table "fork_networks", force: :cascade do |t|
+    t.integer "root_project_id"
+    t.string "deleted_root_project_name"
+  end
+
+  add_index "fork_networks", ["root_project_id"], name: "index_fork_networks_on_root_project_id", unique: true, using: :btree
+
   create_table "forked_project_links", force: :cascade do |t|
     t.integer "forked_to_project_id", null: false
     t.integer "forked_from_project_id", null: false
@@ -1793,6 +1800,7 @@ ActiveRecord::Schema.define(version: 20171006091000) do
   add_foreign_key "environments", "projects", name: "fk_d1c8c1da6a", on_delete: :cascade
   add_foreign_key "events", "projects", on_delete: :cascade
   add_foreign_key "events", "users", column: "author_id", name: "fk_edfd187b6f", on_delete: :cascade
+  add_foreign_key "fork_networks", "projects", column: "root_project_id", name: "fk_e7b436b2b5", on_delete: :nullify
   add_foreign_key "forked_project_links", "projects", column: "forked_to_project_id", name: "fk_434510edb0", on_delete: :cascade
   add_foreign_key "gcp_clusters", "projects", on_delete: :cascade
   add_foreign_key "gcp_clusters", "services", on_delete: :nullify