GraphQL API should return runner total counter stats for instance/group/project

Description

Currently, we display one basic metric about the state of runners in our Runner Admin UI:

This concept could be extended to return this information about the count of different amounts of runners.

Example Metrics

• Active runners
• Inactive runners

Scopes

• Instance
• Group
• Project

Solution description

Specs for this are still TBD

The implementation will require:

• As far as the GraphQL part is concerned, this should be just a question of changing the connection_type for Ci::RunnerType to be Types::CountableConnectionType. This will add a count property to the connection.

  Patch

  diff --git a/app/graphql/types/ci/runner_type.rb b/app/graphql/types/ci/runner_type.rb
  index e62a2b8672f..254d8b7bb29 100644
  --- a/app/graphql/types/ci/runner_type.rb
  +++ b/app/graphql/types/ci/runner_type.rb
  @@ -4,6 +4,7 @@ module Types
     module Ci
       class RunnerType < BaseObject
         edge_type_class(RunnerWebUrlEdge)
  +      connection_type_class(Types::CountableConnectionType)
         graphql_name 'CiRunner'
         authorize :read_runner
         present_using ::Ci::RunnerPresenter

• Index the active column so that the runners(active:true) query performs well. This will likely have an impact on the index_ci_runners_on_contacted_at_and_id_where_inactive partial index.