[7.17](backport #28501) [pre-commit] for linting merge-conflict, pipelines and JJBB

.pre-commit-config.yaml

@@ -0,0 +1,12 @@
+repos:
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.0.1
+    hooks:
+    -   id: check-merge-conflict
+
+-   repo: https://github.com/elastic/apm-pipeline-library.git
+    rev: current
+    hooks:
+    -   id: check-jenkins-pipelines
+        files: ^(.ci/(.*\.groovy|Jenkinsfile)|Jenkinsfile)$
+    -   id: check-jjbb

Jenkinsfile

@@ -225,10 +225,24 @@ def runLinting() {
     }
   }
   mapParallelTasks['default'] = { cmd(label: 'make check-default', script: 'make check-default') }
-
+  mapParallelTasks['pre-commit'] = runPreCommit()
   parallel(mapParallelTasks)
 }
 
+def runPreCommit() {
+  return {
+    withNode(labels: 'ubuntu-18 && immutable', forceWorkspace: true){
+      withGithubNotify(context: 'Check pre-commit', tab: 'tests') {
+        deleteDir()
+        unstashV2(name: 'source', bucket: "${JOB_GCS_BUCKET}", credentialsId: "${JOB_GCS_CREDENTIALS}")
+        dir("${BASE_DIR}"){
+          preCommit(commit: "${GIT_BASE_COMMIT}", junit: true)
+        }
+      }
+    }
+  }
+}
+
 def runBuildAndTest(Map args = [:]) {
   def filterStage = args.get('filterStage', 'mandatory')
   deleteDir()