resolve prefix bugs around job scaling policies

CHANGELOG.md

@@ -8,6 +8,7 @@ IMPROVEMENTS:
 BUG FIXES:
 
  * core: Fixed a bug where unpromoted job versions are used when rescheduling failed allocations [[GH-8691](https://github.com/hashicorp/nomad/issues/8691)]
+ * core: Fixed bugs where scaling policies could be matched against incorrect jobs with a similar prefix [[GH-8753](https://github.com/hashicorp/nomad/issues/8753)]
 
 ## 0.12.3 (August 13, 2020)
 

nomad/scaling_endpoint_test.go

@@ -136,6 +136,7 @@ func TestScalingEndpoint_ListPolicies(t *testing.T) {
 	get := &structs.ScalingPolicyListRequest{
 		QueryOptions: structs.QueryOptions{
 			Region: "global",
+			Namespace: "default",
 		},
 	}
 	var resp structs.ACLPolicyListResponse
@@ -170,6 +171,7 @@ func TestScalingEndpoint_ListPolicies_ACL(t *testing.T) {
 	get := &structs.ScalingPolicyListRequest{
 		QueryOptions: structs.QueryOptions{
 			Region: "global",
+			Namespace: "default",
 		},
 	}
 
@@ -261,6 +263,7 @@ func TestScalingEndpoint_ListPolicies_Blocking(t *testing.T) {
 	req := &structs.ScalingPolicyListRequest{
 		QueryOptions: structs.QueryOptions{
 			Region:        "global",
+			Namespace: "default",
 			MinQueryIndex: 150,
 		},
 	}

nomad/state/state_store.go

@@ -1539,11 +1539,30 @@ func (s *StateStore) DeleteJobTxn(index uint64, namespace, jobID string, txn Txn
 
 // deleteJobScalingPolicies deletes any scaling policies associated with the job
 func (s *StateStore) deleteJobScalingPolicies(index uint64, job *structs.Job, txn *memdb.Txn) error {
-	numDeletedScalingPolicies, err := txn.DeleteAll("scaling_policy", "target_prefix", job.Namespace, job.ID)
+	iter, err := s.ScalingPoliciesByJobTxn(nil, job.Namespace, job.ID, txn)
 	if err != nil {
-		return fmt.Errorf("deleting job scaling policies failed: %v", err)
+		return fmt.Errorf("getting job scaling policies for deletion failed: %v", err)
+	}
+
+	// Put them into a slice so there are no safety concerns while actually
+	// performing the deletes
+	policies := []interface{}{}
+	for {
+		raw := iter.Next()
+		if raw == nil {
+			break
+		}
+		policies = append(policies, raw)
+	}
+
+	// Do the deletes
+	for _, p := range policies {
+		if err := txn.Delete("scaling_policy", p); err != nil {
+			return fmt.Errorf("deleting scaling policy failed: %v", err)
+		}
 	}
-	if numDeletedScalingPolicies > 0 {
+
+	if len(policies) > 0 {
 		if err := txn.Insert("index", &IndexEntry{"scaling_policy", index}); err != nil {
 			return fmt.Errorf("index update failed: %v", err)
 		}
@@ -5332,7 +5351,19 @@ func (s *StateStore) ScalingPoliciesByNamespace(ws memdb.WatchSet, namespace str
 	}
 
 	ws.Add(iter.WatchCh())
-	return iter, nil
+
+	filter := func(raw interface{}) bool {
+		d, ok := raw.(*structs.ScalingPolicy)
+		if !ok {
+			return true
+		}
+
+		return d.Target[structs.ScalingTargetNamespace] != namespace
+	}
+
+	// Wrap the iterator in a filter
+	wrap := memdb.NewFilterIterator(iter, filter)
+	return wrap, nil
 }
 
 func (s *StateStore) ScalingPoliciesByJob(ws memdb.WatchSet, namespace, jobID string) (memdb.ResultIterator, error) {
@@ -5349,7 +5380,19 @@ func (s *StateStore) ScalingPoliciesByJobTxn(ws memdb.WatchSet, namespace, jobID
 	}
 
 	ws.Add(iter.WatchCh())
-	return iter, nil
+
+	filter := func(raw interface{}) bool {
+		d, ok := raw.(*structs.ScalingPolicy)
+		if !ok {
+			return true
+		}
+
+		return d.Target[structs.ScalingTargetJob] != jobID
+	}
+
+	// Wrap the iterator in a filter
+	wrap := memdb.NewFilterIterator(iter, filter)
+	return wrap, nil
 }
 
 func (s *StateStore) ScalingPolicyByID(ws memdb.WatchSet, id string) (*structs.ScalingPolicy, error) {

nomad/state/state_store_test.go

@@ -8640,6 +8640,59 @@ func TestStateStore_UpsertScalingPolicy_Namespace(t *testing.T) {
 	require.ElementsMatch([]string{policy2.ID}, policiesInOtherNamespace)
 }
 
+func TestStateStore_UpsertScalingPolicy_Namespace_PrefixBug(t *testing.T) {
+	t.Parallel()
+	require := require.New(t)
+
+	ns1 := "name"
+	ns2 := "name2" // matches prefix "name"
+	state := testStateStore(t)
+	policy1 := mock.ScalingPolicy()
+	policy1.Target[structs.ScalingTargetNamespace] = ns1
+	policy2 := mock.ScalingPolicy()
+	policy2.Target[structs.ScalingTargetNamespace] = ns2
+
+	ws1 := memdb.NewWatchSet()
+	iter, err := state.ScalingPoliciesByNamespace(ws1, ns1)
+	require.NoError(err)
+	require.Nil(iter.Next())
+
+	ws2 := memdb.NewWatchSet()
+	iter, err = state.ScalingPoliciesByNamespace(ws2, ns2)
+	require.NoError(err)
+	require.Nil(iter.Next())
+
+	err = state.UpsertScalingPolicies(1000, []*structs.ScalingPolicy{policy1, policy2})
+	require.NoError(err)
+	require.True(watchFired(ws1))
+	require.True(watchFired(ws2))
+
+	iter, err = state.ScalingPoliciesByNamespace(nil, ns1)
+	require.NoError(err)
+	policiesInNS1 := []string{}
+	for {
+		raw := iter.Next()
+		if raw == nil {
+			break
+		}
+		policiesInNS1 = append(policiesInNS1, raw.(*structs.ScalingPolicy).ID)
+	}
+	require.ElementsMatch([]string{policy1.ID}, policiesInNS1)
+
+	iter, err = state.ScalingPoliciesByNamespace(nil, ns2)
+	require.NoError(err)
+	policiesInNS2 := []string{}
+	for {
+		raw := iter.Next()
+		if raw == nil {
+			break
+		}
+		policiesInNS2 = append(policiesInNS2, raw.(*structs.ScalingPolicy).ID)
+	}
+	require.ElementsMatch([]string{policy2.ID}, policiesInNS2)
+}
+
+
 func TestStateStore_UpsertJob_UpsertScalingPolicies(t *testing.T) {
 	t.Parallel()
 
@@ -8940,6 +8993,37 @@ func TestStateStore_DeleteJob_DeleteScalingPolicies(t *testing.T) {
 	require.True(index > 1001)
 }
 
+func TestStateStore_DeleteJob_DeleteScalingPoliciesPrefixBug(t *testing.T) {
+	t.Parallel()
+
+	require := require.New(t)
+
+	state := testStateStore(t)
+
+	job := mock.Job()
+	require.NoError(state.UpsertJob(1000, job))
+	job2 := job.Copy()
+	job2.ID = job.ID + "-but-longer"
+	require.NoError(state.UpsertJob(1001, job2))
+
+	policy := mock.ScalingPolicy()
+	policy.Target[structs.ScalingTargetJob] = job.ID
+	policy2 := mock.ScalingPolicy()
+	policy2.Target[structs.ScalingTargetJob] = job2.ID
+	require.NoError(state.UpsertScalingPolicies(1002, []*structs.ScalingPolicy{policy, policy2}))
+
+	// Delete job with the shorter prefix-ID
+	require.NoError(state.DeleteJob(1003, job.Namespace, job.ID))
+
+	// Ensure only the associated scaling policy was deleted, not the one matching the job with the longer ID
+	out, err := state.ScalingPolicyByID(nil, policy.ID)
+	require.NoError(err)
+	require.Nil(out)
+	out, err = state.ScalingPolicyByID(nil, policy2.ID)
+	require.NoError(err)
+	require.NotNil(out)
+}
+
 // This test ensures that deleting a job that doesn't have any scaling policies
 // will not cause the scaling_policy table index to increase, on either job
 // registration or deletion.
@@ -9035,6 +9119,45 @@ func TestStateStore_ScalingPoliciesByJob(t *testing.T) {
 	require.Equal(expect, found)
 }
 
+func TestStateStore_ScalingPoliciesByJob_PrefixBug(t *testing.T) {
+	t.Parallel()
+
+	require := require.New(t)
+
+	jobPrefix := "job-name-" + uuid.Generate()
+
+	state := testStateStore(t)
+	policy1 := mock.ScalingPolicy()
+	policy1.Target[structs.ScalingTargetJob] = jobPrefix
+	policy2 := mock.ScalingPolicy()
+	policy2.Target[structs.ScalingTargetJob] = jobPrefix + "-more"
+
+	// Create the policies
+	var baseIndex uint64 = 1000
+	err := state.UpsertScalingPolicies(baseIndex, []*structs.ScalingPolicy{policy1, policy2})
+	require.NoError(err)
+
+	iter, err := state.ScalingPoliciesByJob(nil,
+		policy1.Target[structs.ScalingTargetNamespace],
+		jobPrefix)
+	require.NoError(err)
+
+	// Ensure we see expected policies
+	count := 0
+	found := []string{}
+	for {
+		raw := iter.Next()
+		if raw == nil {
+			break
+		}
+		count++
+		found = append(found, raw.(*structs.ScalingPolicy).ID)
+	}
+	require.Equal(1, count)
+	expect := []string{policy1.ID}
+	require.Equal(expect, found)
+}
+
 func TestStateStore_UpsertScalingEvent(t *testing.T) {
 	t.Parallel()
 	require := require.New(t)