Handle Scaling Policies in Job Plan endpoint

CHANGELOG.md

@@ -7,6 +7,7 @@ FEATURES:
 
 BUG FIXES:
 
+ * core: Fixed a bug where `nomad job plan` reports success and no updates if the job contains a scaling policy [[GH-8551](https://github.com/hashicorp/nomad/issues/8567)]
  * api: Added missing namespace field to scaling status GET response object [[GH-8527](https://github.com/hashicorp/nomad/issues/8527)]
  * api: Do not allow submission of jobs of type `system` that include task groups with scaling stanzas [[GH-8481](https://github.com/hashicorp/nomad/issues/8481)]
  * vault: Fixed a bug where upgrades from pre-0.11.3 that use Vault can lead to memory spikes and write large Raft messages. [[GH-8553](https://github.com/hashicorp/nomad/issues/8553)]

nomad/job_endpoint.go

@@ -1672,6 +1672,11 @@ func (j *Job) Plan(args *structs.JobPlanRequest, reply *structs.JobPlanResponse)
 		return err
 	}
 
+	// Ensure that all scaling policies have an appropriate ID
+	if err := propagateScalingPolicyIDs(oldJob, args.Job); err != nil {
+		return err
+	}
+
 	var index uint64
 	var updatedIndex uint64
 
@@ -1683,11 +1688,16 @@ func (j *Job) Plan(args *structs.JobPlanRequest, reply *structs.JobPlanResponse)
 		if oldJob.SpecChanged(args.Job) {
 			// Insert the updated Job into the snapshot
 			updatedIndex = oldJob.JobModifyIndex + 1
-			snap.UpsertJob(updatedIndex, args.Job)
+			if err := snap.UpsertJob(updatedIndex, args.Job); err != nil {
+				return err
+			}
 		}
 	} else if oldJob == nil {
 		// Insert the updated Job into the snapshot
-		snap.UpsertJob(100, args.Job)
+		err := snap.UpsertJob(100, args.Job)
+		if err != nil {
+			return err
+		}
 	}
 
 	// Create an eval and mark it as requiring annotations and insert that as well

nomad/job_endpoint_test.go

@@ -5369,6 +5369,42 @@ func TestJobEndpoint_Plan_NoDiff(t *testing.T) {
 	}
 }
 
+// TestJobEndpoint_Plan_Scaling asserts that the plan endpoint handles
+// jobs with scaling stanza
+func TestJobEndpoint_Plan_Scaling(t *testing.T) {
+	t.Parallel()
+
+	s1, cleanupS1 := TestServer(t, func(c *Config) {
+		c.NumSchedulers = 0 // Prevent automatic dequeue
+	})
+	defer cleanupS1()
+	codec := rpcClient(t, s1)
+	testutil.WaitForLeader(t, s1.RPC)
+
+	// Create a plan request
+	job := mock.Job()
+	tg := job.TaskGroups[0]
+	tg.Tasks[0].Resources.MemoryMB = 999999999
+	scaling := &structs.ScalingPolicy{Min: 1, Max: 100}
+	tg.Scaling = scaling.TargetTaskGroup(job, tg)
+	planReq := &structs.JobPlanRequest{
+		Job:  job,
+		Diff: false,
+		WriteRequest: structs.WriteRequest{
+			Region:    "global",
+			Namespace: job.Namespace,
+		},
+	}
+
+	// Try without a token, expect failure
+	var planResp structs.JobPlanResponse
+	err := msgpackrpc.CallWithCodec(codec, "Job.Plan", planReq, &planResp)
+	require.NoError(t, err)
+
+	require.NotEmpty(t, planResp.FailedTGAllocs)
+	require.Contains(t, planResp.FailedTGAllocs, tg.Name)
+}
+
 func TestJobEndpoint_ImplicitConstraints_Vault(t *testing.T) {
 	t.Parallel()