only trigger pipeline on merge requests or pushes to main/stable branches

.gitlab-ci.yml

 ---
+workflow:
+  rules:
+    - if: $CI_PIPELINE_SOURCE == "merge_request_event" || ($CI_PIPELINE_SOURCE == "push" && ($CI_COMMIT_BRANCH == "main" || $CI_COMMIT_BRANCH == "stable"))
+      when: always
+    - when: never
 variables:
   version: 0.0.$CI_PIPELINE_IID
 stages:
@@ -13,6 +18,9 @@ test_job:
     - go test -race -v ./...
 build_job:
   stage: build
+  rules:
+    - if: $CI_COMMIT_REF_NAME =~ /stable/
+      when: always
   image: public.ecr.aws/docker/library/golang:1.21
   parallel:
     matrix:
@@ -26,6 +34,9 @@ build_job:
     expire_in: 5 min
 publish_job:
   stage: publish
+  rules:
+    - if: $CI_COMMIT_REF_NAME =~ /stable/
+      when: always
   image: public.ecr.aws/docker/library/alpine:latest
   tags:
     - docker-privileged