Skip backfill workers for shards that are disabled in selective sync

ee/app/workers/geo/repository_sync_worker.rb

@@ -12,7 +12,7 @@ module Geo
       return unless Gitlab::Geo.geo_database_configured?
       return unless Gitlab::Geo.secondary?
 
-      shards = healthy_shards
+      shards = selective_sync_filter(healthy_shards)
 
       Gitlab::Geo::ShardHealthCache.update(shards)
 
@@ -32,5 +32,11 @@ module Geo
         .compact
         .uniq
     end
+
+    def selective_sync_filter(shards)
+      return shards unless ::Gitlab::Geo.current_node&.selective_sync_by_shards?
+
+      shards & ::Gitlab::Geo.current_node.selective_sync_shards
+    end
   end
 end

spec/ee/spec/workers/geo/repository_sync_worker_spec.rb

@@ -9,6 +9,8 @@ describe Geo::RepositorySyncWorker, :geo, :clean_gitlab_redis_cache do
   let!(:project_in_synced_group) { create(:project, group: synced_group) }
   let!(:unsynced_project) { create(:project) }
 
+  let(:healthy_shard) { project_in_synced_group.repository.storage }
+
   subject { described_class.new }
 
   before do
@@ -32,6 +34,21 @@ describe Geo::RepositorySyncWorker, :geo, :clean_gitlab_redis_cache do
         Sidekiq::Testing.inline! { subject.perform }
       end
 
+      it 'skips backfill for projects on shards excluded by selective sync' do
+        secondary.update!(selective_sync_type: 'shards', selective_sync_shards: [healthy_shard])
+
+        # Report both shards as healthy
+        expect(Gitlab::HealthChecks::FsShardsCheck).to receive(:readiness)
+          .and_return([result(true, healthy_shard), result(true, 'broken')])
+        expect(Gitlab::HealthChecks::GitalyCheck).to receive(:readiness)
+          .and_return([result(true, healthy_shard), result(true, 'broken')])
+
+        expect(Geo::RepositoryShardSyncWorker).to receive(:perform_async).with('default')
+        expect(Geo::RepositoryShardSyncWorker).not_to receive(:perform_async).with('broken')
+
+        Sidekiq::Testing.inline! { subject.perform }
+      end
+
       it 'skips backfill for projects on missing shards' do
         missing_not_synced = create(:project, group: synced_group)
         missing_not_synced.update_column(:repository_storage, 'unknown')
@@ -52,17 +69,14 @@ describe Geo::RepositorySyncWorker, :geo, :clean_gitlab_redis_cache do
       it 'skips backfill for projects with downed Gitaly server' do
         create(:project, group: synced_group, repository_storage: 'broken')
         unhealthy_dirty = create(:project, group: synced_group, repository_storage: 'broken')
-        healthy_shard = project_in_synced_group.repository.storage
 
         create(:geo_project_registry, :synced, :repository_dirty, project: unhealthy_dirty)
 
         # Report only one healthy shard
-        allow(Gitlab::HealthChecks::FsShardsCheck).to receive(:readiness).and_return(
-          [Gitlab::HealthChecks::Result.new(true, nil, { shard: healthy_shard }),
-           Gitlab::HealthChecks::Result.new(true, nil, { shard: 'broken' })])
-        allow(Gitlab::HealthChecks::GitalyCheck).to receive(:readiness).and_return(
-          [Gitlab::HealthChecks::Result.new(true, nil, { shard: healthy_shard }),
-           Gitlab::HealthChecks::Result.new(false, nil, { shard: 'broken' })])
+        expect(Gitlab::HealthChecks::FsShardsCheck).to receive(:readiness)
+          .and_return([result(true, healthy_shard), result(true, 'broken')])
+        expect(Gitlab::HealthChecks::GitalyCheck).to receive(:readiness)
+          .and_return([result(true, healthy_shard), result(false, 'broken')])
 
         expect(Geo::RepositoryShardSyncWorker).to receive(:perform_async).with(healthy_shard)
         expect(Geo::RepositoryShardSyncWorker).not_to receive(:perform_async).with('broken')
@@ -71,4 +85,8 @@ describe Geo::RepositorySyncWorker, :geo, :clean_gitlab_redis_cache do
       end
     end
   end
+
+  def result(success, shard)
+    Gitlab::HealthChecks::Result.new(success, nil, { shard: shard })
+  end
 end