Improve how we could cancel pipelines:

* Introduce `HasStatus.cancelable` which we might be able to cancel
* Cancel and check upon `cancelable`
* Also cancel on `CommitStatus` rather than just `Ci::Build`

Fixes #23635

Fixes #17845

app/models/ci/pipeline.rb

@@ -167,11 +167,11 @@ module Ci
     end
 
     def cancelable?
-      builds.running_or_pending.any?
+      statuses.cancelable.any?
     end
 
     def cancel_running
-      builds.running_or_pending.each(&:cancel)
+      statuses.cancelable.each(&:cancel)
     end
 
     def retry_failed(user)

app/models/concerns/has_status.rb

@@ -73,6 +73,10 @@ module HasStatus
     scope :skipped, -> { where(status: 'skipped')  }
     scope :running_or_pending, -> { where(status: [:running, :pending]) }
     scope :finished, -> { where(status: [:success, :failed, :canceled]) }
+
+    scope :cancelable, -> do
+      where(status: [:running, :pending, :created])
+    end
   end
 
   def started?

changelogs/unreleased/fix-cancelling-pipelines.yml

+---
+title: Fix cancelling created or external pipelines
+merge_request: 7508
+author:

spec/features/projects/pipelines_spec.rb

@@ -90,8 +90,8 @@ describe "Pipelines" do
           visit namespace_project_pipelines_path(project.namespace, project)
         end
 
-        it 'is not cancelable' do
-          expect(page).not_to have_link('Cancel')
+        it 'is cancelable' do
+          expect(page).to have_link('Cancel')
         end
 
         it 'has pipeline running' do

spec/models/ci/pipeline_spec.rb

@@ -402,6 +402,46 @@ describe Ci::Pipeline, models: true do
     end
   end
 
+  describe '#cancelable?' do
+    subject { pipeline.cancelable? }
+
+    %i[created running pending].each do |status|
+      context "when there is a build #{status}" do
+        before do
+          create(:ci_build, status, pipeline: pipeline)
+        end
+
+        it { is_expected.to be_truthy }
+      end
+
+      context "when there is an external job #{status}" do
+        before do
+          create(:generic_commit_status, status, pipeline: pipeline)
+        end
+
+        it { is_expected.to be_truthy }
+      end
+    end
+
+    %i[success failed canceled].each do |status|
+      context "when there is a build #{status}" do
+        before do
+          create(:ci_build, status, pipeline: pipeline)
+        end
+
+        it { is_expected.to be_falsey }
+      end
+
+      context "when there is an external job #{status}" do
+        before do
+          create(:generic_commit_status, status, pipeline: pipeline)
+        end
+
+        it { is_expected.to be_falsey }
+      end
+    end
+  end
+
   describe '#execute_hooks' do
     let!(:build_a) { create_build('a', 0) }
     let!(:build_b) { create_build('b', 1) }