Use fog_spec_helper for blobstore specs needing clean state

Move Fog mock reset from global spec_helper to opt-in fog_spec_helper.
This prevents fog reset from running for all specs, which caused
conflicts with migration specs that stub Config.get differently.

The fog_spec_helper now:
- Uses metadata-based hook (:fog_isolation) that only runs for tagged specs
- Resets Fog mocks and recreates buckets before each tagged test
- Avoids interfering with specs that mock Config differently

24 blobstore-related specs are tagged with :fog_isolation metadata.

Author: johha

spec/fog_spec_helper.rb

@@ -0,0 +1,21 @@
+# Use this helper for specs that need Fog/blobstore functionality with
+# a clean state between tests (upload, download, delete operations).
+#
+# This helper resets Fog mocks and recreates buckets before each test.
+#
+# For specs that don't need blobstore isolation, use spec_helper instead.
+
+require 'spec_helper'
+
+RSpec.configure do |config|
+  config.before(:each, :fog_isolation) do
+    Fog::Mock.reset
+
+    if Fog.mock?
+      CloudController::DependencyLocator.instance.droplet_blobstore.ensure_bucket_exists
+      CloudController::DependencyLocator.instance.package_blobstore.ensure_bucket_exists
+      CloudController::DependencyLocator.instance.global_app_bits_cache.ensure_bucket_exists
+      CloudController::DependencyLocator.instance.buildpack_blobstore.ensure_bucket_exists
+    end
+  end
+end

spec/unit/controllers/runtime/buildpack_bits_controller_spec.rb

@@ -1,9 +1,9 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 ## NOTICE: Prefer request specs over controller specs as per ADR #0003 ##
 
 module VCAP::CloudController
-  RSpec.describe VCAP::CloudController::BuildpackBitsController do
+  RSpec.describe VCAP::CloudController::BuildpackBitsController, :fog_isolation do
     let(:user) { make_user }
     let(:filename) { 'file.zip' }
     let(:sha_valid_zip) { Digester.new(algorithm: OpenSSL::Digest::SHA256).digest_file(valid_zip) }

spec/unit/controllers/runtime/buildpacks_controller_spec.rb

@@ -1,9 +1,9 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 ## NOTICE: Prefer request specs over controller specs as per ADR #0003 ##
 
 module VCAP::CloudController
-  RSpec.describe VCAP::CloudController::BuildpacksController do
+  RSpec.describe VCAP::CloudController::BuildpacksController, :fog_isolation do
     def ordered_buildpacks
       Buildpack.order(:position).map { |bp| [bp.name, bp.position] }
     end

spec/unit/controllers/runtime/stagings_controller_spec.rb

@@ -1,4 +1,4 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 ## NOTICE: Prefer request specs over controller specs as per ADR #0003 ##
 
@@ -164,7 +164,7 @@ module VCAP::CloudController
     end
   end
 
-  RSpec.describe StagingsController do
+  RSpec.describe StagingsController, :fog_isolation do
     let(:timeout_in_seconds) { 120 }
     let(:cc_addr) { '1.2.3.4' }
     let(:cc_port) { 5678 }

spec/unit/jobs/runtime/blobstore_delete_spec.rb

@@ -1,8 +1,8 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 module VCAP::CloudController
   module Jobs::Runtime
-    RSpec.describe BlobstoreDelete, job_context: :worker do
+    RSpec.describe BlobstoreDelete, :fog_isolation, job_context: :worker do
       let(:key) { 'key' }
       subject(:job) do
         BlobstoreDelete.new(key, :droplet_blobstore)

spec/unit/jobs/runtime/blobstore_upload_spec.rb

@@ -1,8 +1,8 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 module VCAP::CloudController
   module Jobs::Runtime
-    RSpec.describe BlobstoreUpload, job_context: :worker do
+    RSpec.describe BlobstoreUpload, :fog_isolation, job_context: :worker do
       let(:local_file) { Tempfile.new('tmpfile') }
       let(:blobstore_key) { 'key' }
       let(:blobstore_name) { :droplet_blobstore }

spec/unit/jobs/runtime/buildpack_cache_cleanup_spec.rb

@@ -1,8 +1,8 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 module VCAP::CloudController
   module Jobs::Runtime
-    RSpec.describe BuildpackCacheCleanup, job_context: :worker do
+    RSpec.describe BuildpackCacheCleanup, :fog_isolation, job_context: :worker do
       let(:cc_addr) { '1.2.3.4' }
       let(:cc_port) { 5678 }
       let(:orphan_key) { 'orphan-key' }

spec/unit/jobs/v3/buildpack_cache_cleanup_spec.rb

@@ -1,8 +1,8 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 module VCAP::CloudController
   module Jobs::V3
-    RSpec.describe BuildpackCacheCleanup, job_context: :worker do
+    RSpec.describe BuildpackCacheCleanup, :fog_isolation, job_context: :worker do
       let(:cc_addr) { '1.2.3.4' }
       let(:cc_port) { 5678 }
       let(:orphan_key) { 'orphan-key' }

spec/unit/jobs/v3/buildpack_cache_delete_spec.rb

@@ -1,9 +1,9 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 require 'jobs/v3/buildpack_cache_delete'
 
 module VCAP::CloudController
   module Jobs::V3
-    RSpec.describe BuildpackCacheDelete, job_context: :worker do
+    RSpec.describe BuildpackCacheDelete, :fog_isolation, job_context: :worker do
       let(:app_guid) { 'some-guid' }
       let(:local_dir) { Dir.mktmpdir }
       let!(:blobstore) do

spec/unit/jobs/v3/buildpack_cache_upload_spec.rb

@@ -1,8 +1,8 @@
-require 'spec_helper'
+require 'fog_spec_helper'
 
 module VCAP::CloudController
   module Jobs::V3
-    RSpec.describe BuildpackCacheUpload, job_context: :api do
+    RSpec.describe BuildpackCacheUpload, :fog_isolation, job_context: :api do
       subject(:job) { BuildpackCacheUpload.new(local_path: local_file.path, app_guid: app.guid, stack_name: 'some-stack') }
 
       let(:app) { AppModel.make(:buildpack) }