Add multiple improvements to Geo development docs

.gitlab/issue_templates/Geo Replicate a new Git repository type.md

@@ -56,9 +56,7 @@ Geo secondary sites have a [Geo tracking database](https://gitlab.com/gitlab-org
   ```ruby
   # frozen_string_literal: true
 
-  class CreateCoolWidgetRegistry < ActiveRecord::Migration[6.0]
-    include Gitlab::Database::MigrationHelpers
-
+  class CreateCoolWidgetRegistry < Gitlab::Database::Migration[1.0]
     disable_ddl_transaction!
 
     def up
@@ -126,9 +124,7 @@ The Geo primary site needs to checksum every replicable so secondaries can verif
   ```ruby
   # frozen_string_literal: true
 
-  class CreateCoolWidgetStates < ActiveRecord::Migration[6.0]
-    include Gitlab::Database::MigrationHelpers
-
+  class CreateCoolWidgetStates < Gitlab::Database::Migration[1.0]
     VERIFICATION_STATE_INDEX_NAME = "index_cool_widget_states_on_verification_state"
     PENDING_VERIFICATION_INDEX_NAME = "index_cool_widget_states_pending_verification"
     FAILED_VERIFICATION_INDEX_NAME = "index_cool_widget_states_failed_verification"
@@ -137,7 +133,6 @@ The Geo primary site needs to checksum every replicable so secondaries can verif
     disable_ddl_transaction!
 
     def up
-      unless table_exists?(:cool_widget_states)
       with_lock_retries do
         create_table :cool_widget_states, id: false do |t|
           t.references :cool_widget, primary_key: true, null: false, foreign_key: { on_delete: :cascade }
@@ -155,7 +150,6 @@ The Geo primary site needs to checksum every replicable so secondaries can verif
           t.index :verification_state, where: "(verification_state = 0 OR verification_state = 3)", name: NEEDS_VERIFICATION_INDEX_NAME
         end
       end
-      end
 
       add_text_limit :cool_widget_states, :verification_failure, 255
     end
@@ -209,6 +203,8 @@ That's all of the required database changes.
 
     has_one :cool_widget_state, autosave: false, inverse_of: :cool_widget, class_name: 'Geo::CoolWidgetState'
 
+    after_save :save_verification_details
+
     delegate :verification_retry_at, :verification_retry_at=,
              :verified_at, :verified_at=,
              :verification_checksum, :verification_checksum=,
@@ -223,6 +219,8 @@ That's all of the required database changes.
     scope :checksummed, -> { joins(:cool_widget_state).where.not(cool_widget_states: { verification_checksum: nil } ) }
     scope :not_checksummed, -> { joins(:cool_widget_state).where(cool_widget_states: { verification_checksum: nil } ) }
 
+    scope :available_verifiables, -> { joins(:cool_widget_state) }
+
     # Override the `all` default if not all records can be replicated. For an
     # example of an existing Model that needs to do this, see
     # `EE::MergeRequestDiff`.

.gitlab/issue_templates/Geo Replicate a new blob type.md

@@ -58,13 +58,10 @@ Geo secondary sites have a [Geo tracking database](https://gitlab.com/gitlab-org
   ```ruby
   # frozen_string_literal: true
 
-  class CreateCoolWidgetRegistry < ActiveRecord::Migration[6.0]
-    include Gitlab::Database::MigrationHelpers
-
+  class CreateCoolWidgetRegistry < Gitlab::Database::Migration[1.0]
     disable_ddl_transaction!
 
     def up
-      unless table_exists?(:cool_widget_registry)
       ActiveRecord::Base.transaction do
         create_table :cool_widget_registry, id: :bigserial, force: :cascade do |t|
           t.bigint :cool_widget_id, null: false
@@ -96,7 +93,6 @@ Geo secondary sites have a [Geo tracking database](https://gitlab.com/gitlab-org
         end
       end
     end
-    end
 
     def down
       drop_table :cool_widget_registry
@@ -130,9 +126,7 @@ The Geo primary site needs to checksum every replicable so secondaries can verif
   ```ruby
   # frozen_string_literal: true
 
-  class CreateCoolWidgetStates < ActiveRecord::Migration[6.0]
-    include Gitlab::Database::MigrationHelpers
-
+  class CreateCoolWidgetStates < Gitlab::Database::Migration[1.0]
     VERIFICATION_STATE_INDEX_NAME = "index_cool_widget_states_on_verification_state"
     PENDING_VERIFICATION_INDEX_NAME = "index_cool_widget_states_pending_verification"
     FAILED_VERIFICATION_INDEX_NAME = "index_cool_widget_states_failed_verification"
@@ -141,7 +135,6 @@ The Geo primary site needs to checksum every replicable so secondaries can verif
     disable_ddl_transaction!
 
     def up
-      unless table_exists?(:cool_widget_states)
       with_lock_retries do
         create_table :cool_widget_states, id: false do |t|
           t.references :cool_widget, primary_key: true, null: false, foreign_key: { on_delete: :cascade }
@@ -159,7 +152,6 @@ The Geo primary site needs to checksum every replicable so secondaries can verif
           t.index :verification_state, where: "(verification_state = 0 OR verification_state = 3)", name: NEEDS_VERIFICATION_INDEX_NAME
         end
       end
-      end
 
       add_text_limit :cool_widget_states, :verification_failure, 255
     end
@@ -213,6 +205,8 @@ That's all of the required database changes.
 
     has_one :cool_widget_state, autosave: false, inverse_of: :cool_widget, class_name: 'Geo::CoolWidgetState'
 
+    after_save :save_verification_details
+
     delegate :verification_retry_at, :verification_retry_at=,
              :verified_at, :verified_at=,
              :verification_checksum, :verification_checksum=,
@@ -227,6 +221,8 @@ That's all of the required database changes.
     scope :checksummed, -> { joins(:cool_widget_state).where.not(cool_widget_states: { verification_checksum: nil } ) }
     scope :not_checksummed, -> { joins(:cool_widget_state).where(cool_widget_states: { verification_checksum: nil } ) }
 
+    scope :available_verifiables, -> { joins(:cool_widget_state) }
+
     # Override the `all` default if not all records can be replicated. For an
     # example of an existing Model that needs to do this, see
     # `EE::MergeRequestDiff`.