Migrate issues authored by deleted user to the Ghost user

3 files changed, 52 insertions, 1 deletions

diff --git a/db/migrate/20170825104051_migrate_issues_to_ghost_user.rb b/db/migrate/20170825104051_migrate_issues_to_ghost_user.rb
new file mode 100644
index 00000000000..294141e4fdb
--- /dev/null
+++ b/db/migrate/20170825104051_migrate_issues_to_ghost_user.rb
@@ -0,0 +1,36 @@
+class MigrateIssuesToGhostUser < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  class User < ActiveRecord::Base
+    self.table_name = 'users'
+  end
+
+  class Issue < ActiveRecord::Base
+    self.table_name = 'issues'
+
+    include ::EachBatch
+  end
+
+  def reset_column_in_migration_models
+    ActiveRecord::Base.clear_cache!
+
+    ::User.reset_column_information
+  end
+
+  def up
+    reset_column_in_migration_models
+
+    # we use the model method because rewriting it is too complicated and would require copying multiple methods
+    ghost_id = ::User.ghost.id
+
+    Issue.where('NOT EXISTS (?)', User.unscoped.select(1).where('issues.author_id = users.id')).each_batch do |relation|
+      relation.update_all(author_id: ghost_id)
+    end
+  end
+
+  def down
+  end
+end
diff --git a/db/migrate/20170901071411_add_foreign_key_to_issue_author.rb b/db/migrate/20170901071411_add_foreign_key_to_issue_author.rb
new file mode 100644
index 00000000000..ab6e9fb565a
--- /dev/null
+++ b/db/migrate/20170901071411_add_foreign_key_to_issue_author.rb
@@ -0,0 +1,14 @@
+class AddForeignKeyToIssueAuthor < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_foreign_key(:issues, :users, column: :author_id, on_delete: :nullify)
+  end
+
+  def down
+    remove_foreign_key(:issues, column: :author_id)
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index a5f867df9ae..9b45861cde7 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170824162758) do
+ActiveRecord::Schema.define(version: 20170901071411) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -1707,6 +1707,7 @@ ActiveRecord::Schema.define(version: 20170824162758) do
   add_foreign_key "issue_assignees", "users", name: "fk_5e0c8d9154", on_delete: :cascade
   add_foreign_key "issue_metrics", "issues", on_delete: :cascade
   add_foreign_key "issues", "projects", name: "fk_899c8f3231", on_delete: :cascade
+  add_foreign_key "issues", "users", column: "author_id", name: "fk_05f1e72feb", on_delete: :cascade
   add_foreign_key "label_priorities", "labels", on_delete: :cascade
   add_foreign_key "label_priorities", "projects", on_delete: :cascade
   add_foreign_key "labels", "namespaces", column: "group_id", on_delete: :cascade