Fix spec violations for internal_ids cross-database modifications

At present all the spec violations we found are false positives caused
by the fact that `ensure_project_iid!` is not called on the pipeline
before saving. We can remove many of them by just doing this in the
`after(:build)` for the `ci_pipeline` factory.

There are still a couple in `atomic_internal_id_shared_examples` but
these are specs that are explicitly trying to do things in transactions
and rolling things back so they aren't really representative of real
application code so it seemed easier to just wrap these in `allow_...`
for now and extract an issue if we ever want to actually refactor these
tests. It may be tricky to refactor them because they are used for other
models where these transaction behaviours being tested do indeed matter.

spec/factories/ci/pipelines.rb

@@ -18,15 +18,13 @@ FactoryBot.define do
     transient { child_of { nil } }
     transient { upstream_of { nil } }
 
-    before(:create) do |pipeline, evaluator|
-      pipeline.ensure_project_iid!
-    end
-
     after(:build) do |pipeline, evaluator|
       if evaluator.child_of
         pipeline.project = evaluator.child_of.project
         pipeline.source = :parent_pipeline
       end
+
+      pipeline.ensure_project_iid!
     end
 
     after(:create) do |pipeline, evaluator|

spec/support/database/cross-database-modification-allowlist.yml

@@ -46,7 +46,6 @@
 - "./spec/models/ci/group_variable_spec.rb"
 - "./spec/models/ci/job_artifact_spec.rb"
 - "./spec/models/ci/job_variable_spec.rb"
-- "./spec/models/ci/pipeline_spec.rb"
 - "./spec/models/ci/runner_spec.rb"
 - "./spec/models/ci/variable_spec.rb"
 - "./spec/models/clusters/applications/runner_spec.rb"

spec/support/shared_examples/models/atomic_internal_id_shared_examples.rb

@@ -80,15 +80,22 @@ RSpec.shared_examples 'AtomicInternalId' do |validate_presence: true|
       it 'calls InternalId.generate_next and sets internal id attribute' do
         iid = rand(1..1000)
 
-        expect(InternalId).to receive(:generate_next).with(instance, scope_attrs, usage, any_args).and_return(iid)
+        # Need to do this before evaluating instance otherwise it gets set
+        # already in factory
+        allow(InternalId).to receive(:generate_next).and_return(iid)
+
         subject
         expect(read_internal_id).to eq(iid)
+
+        expect(InternalId).to have_received(:generate_next).with(instance, scope_attrs, usage, any_args)
       end
 
       it 'does not overwrite an existing internal id' do
         write_internal_id(4711)
 
-        expect { subject }.not_to change { read_internal_id }
+        allow_cross_database_modification_within_transaction(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/347091') do
+          expect { subject }.not_to change { read_internal_id }
+        end
       end
 
       context 'when the instance has an internal ID set' do
@@ -101,6 +108,7 @@ RSpec.shared_examples 'AtomicInternalId' do |validate_presence: true|
             .to receive(:track_greatest)
             .with(instance, scope_attrs, usage, internal_id, any_args)
             .and_return(internal_id)
+
           subject
         end
       end
@@ -110,7 +118,11 @@ RSpec.shared_examples 'AtomicInternalId' do |validate_presence: true|
       context 'when the internal id has been changed' do
         context 'when the internal id is automatically set' do
           it 'clears it on the instance' do
-            expect_iid_to_be_set_and_rollback
+            write_internal_id(nil)
+
+            allow_cross_database_modification_within_transaction(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/347091') do
+              expect_iid_to_be_set_and_rollback
+            end
 
             expect(read_internal_id).to be_nil
           end
@@ -120,7 +132,9 @@ RSpec.shared_examples 'AtomicInternalId' do |validate_presence: true|
           it 'does not clear it on the instance' do
             write_internal_id(100)
 
-            expect_iid_to_be_set_and_rollback
+            allow_cross_database_modification_within_transaction(url: 'https://gitlab.com/gitlab-org/gitlab/-/issues/347091') do
+              expect_iid_to_be_set_and_rollback
+            end
 
             expect(read_internal_id).not_to be_nil
           end