Merge pull request 'Use loopback for host builder probes' (#5) from fix/gitea-builder-loopback-20260727 into main

Run upstream watcher only on GitHub

.github/workflows/candidate.yml

@@ -18,6 +18,8 @@ jobs:
       - uses: ruby/setup-ruby@003a5c4d8d6321bd302e38f6f0ec593f77f06600 # v1
         with:
           ruby-version: "3.4"
+      - name: Install standalone test dependency
+        run: gem install minitest --version 6.0.6 --no-document
       - run: |
           ruby test/repository_test.rb
           ruby test/runtime_tuple_promoter_test.rb
@@ -267,9 +269,12 @@ jobs:
           retention-days: 30
 
   exact-image-contract-gitea:
-    if: github.server_url != 'https://github.com'
+    if: >-
+      github.server_url != 'https://github.com' &&
+      (github.event_name == 'workflow_dispatch' ||
+      (github.event_name == 'push' && github.ref == 'refs/heads/main'))
     needs: prepare
-    runs-on: ubuntu-latest
+    runs-on: heyoka-image-build
     name: Gitea full exact image matrix
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
@@ -299,9 +304,7 @@ jobs:
           test "$actual_client_sha" = "$EXPECTED_CLIENT_SHA"
           echo "value=$actual_client_sha" >> "$GITHUB_OUTPUT"
       - name: Resolve the private Docker host transport
-        run: |
-          probe_host="$(ruby scripts/private_default_gateway.rb)"
-          echo "OPENCODE_PROBE_HOST=$probe_host" >> "$GITHUB_ENV"
+        run: echo "OPENCODE_PROBE_HOST=127.0.0.1" >> "$GITHUB_ENV"
       - name: Exercise the complete manifest matrix without artifact claims
         env:
           BUNDLE_GEMFILE: ${{ github.workspace }}/ruby-client/Gemfile

.github/workflows/watch-upstream.yml

@@ -15,6 +15,7 @@ concurrency:
 
 jobs:
   open-compatibility-pr:
+    if: github.server_url == 'https://github.com'
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0

test/repository_test.rb

@@ -335,6 +335,13 @@ class RepositoryTest < Minitest::Test
     end
   end
 
+  def test_repository_job_installs_its_pinned_standalone_test_dependency
+    workflow = File.read(File.join(ROOT, ".github/workflows/candidate.yml"))
+    repository_job = workflow.split(/^  repository:\n/, 2).fetch(1).split(/^  prepare:\n/, 2).fetch(0)
+
+    assert_includes repository_job, "gem install minitest --version 6.0.6 --no-document"
+  end
+
   def test_candidate_workflow_verifies_and_preserves_the_lockstep_client_tuple
     workflow = File.read(File.join(ROOT, ".github/workflows/candidate.yml"))
 
@@ -374,8 +381,7 @@ class RepositoryTest < Minitest::Test
     assert_includes workflow, "exact-image-contract-gitea:"
     assert_includes workflow, "if: github.server_url != 'https://github.com'"
     assert_includes workflow, "run: scripts/run_image_matrix_contract.sh"
-    assert_includes workflow, 'probe_host="$(ruby scripts/private_default_gateway.rb)"'
-    assert_includes workflow, 'echo "OPENCODE_PROBE_HOST=$probe_host" >> "$GITHUB_ENV"'
+    assert_includes workflow, 'echo "OPENCODE_PROBE_HOST=127.0.0.1" >> "$GITHUB_ENV"'
     assert_operator workflow.scan('BUNDLE_GEMFILE: ${{ github.workspace }}/ruby-client/Gemfile').length, :>=, 2
     assert_operator workflow.scan("generated JSON is transient and is not review evidence").length, :>=, 3
 
@@ -383,6 +389,20 @@ class RepositoryTest < Minitest::Test
     refute_includes gitea_job, "actions/upload-artifact@"
   end
 
+  def test_gitea_exact_image_contract_uses_the_trusted_builder_only_for_main_pushes_or_manual_dispatches
+    workflow = File.read(File.join(ROOT, ".github/workflows/candidate.yml"))
+    ordinary_jobs = workflow.split(/^  exact-image-contract:\n/, 2).fetch(0)
+    github_job, gitea_job = workflow.split(/^  exact-image-contract:\n/, 2).fetch(1)
+      .split(/^  exact-image-contract-gitea:\n/, 2)
+
+    assert_equal 4, ordinary_jobs.scan("runs-on: ubuntu-latest").length
+    assert_includes github_job, "runs-on: ubuntu-latest"
+    assert_includes gitea_job, "runs-on: heyoka-image-build"
+    assert_includes gitea_job, "github.server_url != 'https://github.com'"
+    assert_includes gitea_job, "github.event_name == 'workflow_dispatch'"
+    assert_includes gitea_job, "github.event_name == 'push' && github.ref == 'refs/heads/main'"
+  end
+
   def test_gitea_matrix_runner_uses_every_generated_entry_without_hardcoded_coordinates
     runner = File.read(File.join(ROOT, "scripts/run_image_matrix_contract.sh"))
 

test/watcher_test.rb

@@ -170,6 +170,10 @@ class WatcherTest < Minitest::Test
   def test_workflow_can_only_update_manifests_and_open_a_pr
     workflow = File.read(File.join(ROOT, ".github/workflows/watch-upstream.yml"))
 
+    assert_match(
+      /\n  open-compatibility-pr:\n    if: github\.server_url == 'https:\/\/github\.com'\n    runs-on:/,
+      workflow
+    )
     assert_includes workflow, "contents: write"
     assert_includes workflow, "pull-requests: write"
     assert_includes workflow, "git add manifests/image-matrix.json manifests/upstream.json"