api: Ignore User provided ParentID (#10424)

ParentID is an internal field that Nomad sets for dispatched or parameterized jobs. Job submitters should not be able to set it directly, as that messes up children tracking.

Fixes #10422 . It specifically stops the scheduler from honoring the ParentID. The reason failure and why the scheduler didn't schedule that job once it was created is very interesting and requires follow up with a more technical issue.

command/agent/job_endpoint.go

@@ -782,7 +782,6 @@ func ApiJobToStructJob(job *api.Job) *structs.Job {
 		Region:         *job.Region,
 		Namespace:      *job.Namespace,
 		ID:             *job.ID,
-		ParentID:       *job.ParentID,
 		Name:           *job.Name,
 		Type:           *job.Type,
 		Priority:       *job.Priority,

command/agent/job_endpoint_test.go

@@ -221,6 +221,68 @@ func TestHTTP_JobsRegister(t *testing.T) {
 	})
 }
 
+func TestHTTP_JobsRegister_IgnoresParentID(t *testing.T) {
+	t.Parallel()
+	httpTest(t, nil, func(s *TestAgent) {
+		// Create the job
+		job := MockJob()
+		parentID := "somebadparentid"
+		job.ParentID = &parentID
+		args := api.JobRegisterRequest{
+			Job:          job,
+			WriteRequest: api.WriteRequest{Region: "global"},
+		}
+		buf := encodeReq(args)
+
+		// Make the HTTP request
+		req, err := http.NewRequest("PUT", "/v1/jobs", buf)
+		require.NoError(t, err)
+		respW := httptest.NewRecorder()
+
+		// Make the request
+		obj, err := s.Server.JobsRequest(respW, req)
+		require.NoError(t, err)
+
+		// Check the response
+		reg := obj.(structs.JobRegisterResponse)
+		require.NotEmpty(t, reg.EvalID)
+
+		// Check for the index
+		require.NotEmpty(t, respW.HeaderMap.Get("X-Nomad-Index"))
+
+		// Check the job is registered
+		getReq := structs.JobSpecificRequest{
+			JobID: *job.ID,
+			QueryOptions: structs.QueryOptions{
+				Region:    "global",
+				Namespace: structs.DefaultNamespace,
+			},
+		}
+		var getResp structs.SingleJobResponse
+		err = s.Agent.RPC("Job.GetJob", &getReq, &getResp)
+		require.NoError(t, err)
+
+		require.NotNil(t, getResp.Job)
+		require.Equal(t, *job.ID, getResp.Job.ID)
+		require.Empty(t, getResp.Job.ParentID)
+
+		// check the eval exists
+		evalReq := structs.EvalSpecificRequest{
+			EvalID: reg.EvalID,
+			QueryOptions: structs.QueryOptions{
+				Region:    "global",
+				Namespace: structs.DefaultNamespace,
+			},
+		}
+		var evalResp structs.SingleEvalResponse
+		err = s.Agent.RPC("Eval.GetEval", &evalReq, &evalResp)
+		require.NoError(t, err)
+
+		require.NotNil(t, evalResp.Eval)
+		require.Equal(t, reg.EvalID, evalResp.Eval.ID)
+	})
+}
+
 // Test that ACL token is properly threaded through to the RPC endpoint
 func TestHTTP_JobsRegister_ACL(t *testing.T) {
 	t.Parallel()
@@ -2172,7 +2234,6 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 		Namespace:      "foo",
 		VaultNamespace: "ghi789",
 		ID:             "foo",
-		ParentID:       "lol",
 		Name:           "name",
 		Type:           "service",
 		Priority:       50,
@@ -2673,7 +2734,6 @@ func TestJobs_ApiJobToStructsJob(t *testing.T) {
 		Region:      "global",
 		Namespace:   "foo",
 		ID:          "foo",
-		ParentID:    "lol",
 		Name:        "name",
 		Type:        "system",
 		Priority:    50,