ci: Build QA image for the non-merged commit

This is needed so that GitLab image built in omnibus-gitlab-mirror and
QA image are in sync.

This should resolve
https://gitlab.com/gitlab-org/gitlab/-/issues/330326.
Signed-off-by: Rémy Coutable <remy@rymai.me>

.gitlab/ci/build-images.gitlab-ci.yml

@@ -9,8 +9,18 @@ build-qa-image:
     - .build-images:rules:build-qa-image
   stage: build-images
   needs: []
+  variables:
+    QA_IMAGE: "${CI_REGISTRY}/${CI_PROJECT_PATH}/gitlab-ee-qa:${CI_COMMIT_REF_SLUG}"
   script:
-    - export QA_IMAGE="${CI_REGISTRY}/${CI_PROJECT_PATH}/gitlab-ee-qa:${CI_COMMIT_REF_SLUG}"
+    # With .git/hooks/post-checkout in place, Git tries to pull LFS objects, but the image doesn't have Git LFS, and we actually don't care about it for this specific so we just remove the file.
+    # Without removing the file, the error is as follows: "This repository is configured for Git LFS but 'git-lfs' was not found on your path. If you no longer wish to use Git LFS, remove this hook by deleting .git/hooks/post-checkout."
+    - rm .git/hooks/post-checkout
+    # Use $CI_MERGE_REQUEST_SOURCE_BRANCH_SHA so that GitLab image built in omnibus-gitlab-mirror and QA image are in sync.
+    # This falls back to $CI_COMMIT_SHA (the default checked out commit) for the non-merged result pipelines.
+    # See https://docs.gitlab.com/ee/development/testing_guide/end_to_end/index.html#with-pipeline-for-merged-results.
+    - if [ -n "$CI_MERGE_REQUEST_SOURCE_BRANCH_SHA" ]; then
+        git checkout -f ${CI_MERGE_REQUEST_SOURCE_BRANCH_SHA};
+      fi
     - /kaniko/executor --context=${CI_PROJECT_DIR} --dockerfile=${CI_PROJECT_DIR}/qa/Dockerfile --destination=${QA_IMAGE} --cache=true
   retry: 2
 

.gitlab/ci/global.gitlab-ci.yml

@@ -128,7 +128,7 @@
 
 .use-kaniko:
   image:
-    name: gcr.io/kaniko-project/executor:debug-v1.3.0
+    name: registry.gitlab.com/gitlab-org/gitlab-build-images:kaniko
     entrypoint: [""]
   before_script:
     - source scripts/utils.sh

scripts/trigger-build

@@ -136,7 +136,7 @@ module Trigger
 
     def extra_variables
       # Use CI_MERGE_REQUEST_SOURCE_BRANCH_SHA for omnibus checkouts due to pipeline for merged results
-      # and fallback to CI_COMMIT_SHA (merged result commit) for the non-MR pipelines.
+      # and fallback to CI_COMMIT_SHA for the non-MR pipelines.
       # See https://docs.gitlab.com/ee/development/testing_guide/end_to_end/index.html#with-pipeline-for-merged-results.
       # We also set IMAGE_TAG so the GitLab Docker image is tagged with that SHA.
       source_sha = Trigger.non_empty_variable_value('CI_MERGE_REQUEST_SOURCE_BRANCH_SHA') || ENV['CI_COMMIT_SHA']