Update logging for unrunable pipelines (#4843)

Signed-off-by: Christian Kruse <[email protected]>

Signed-off-by: Christian Kruse <[email protected]>

backend/pipeline/adapter.go

@@ -2,6 +2,7 @@ package pipeline
 
 import (
 	"context"
+	"fmt"
 
 	corev2 "github.com/sensu/sensu-go/api/core/v2"
 )
@@ -14,9 +15,28 @@ type Adapter interface {
 	Run(context.Context, *corev2.ResourceReference, interface{}) error
 }
 
+// ErrMisconfiguredPipeline interface implemented by errors that indicate
+// a misconfigured pipeline that cannot be executed.
+type ErrMisconfiguredPipeline interface {
+	MisconfiguredPipeline()
+}
+
 // ErrNoWorkflows is returned when a pipeline has no workflows
 type ErrNoWorkflows struct{}
 
 func (e *ErrNoWorkflows) Error() string {
 	return "pipeline has no workflows"
 }
+
+func (e *ErrNoWorkflows) MisconfiguredPipeline() {}
+
+// ErrNoLegacyHandlers is returned when no legacy handlers exist
+type errNoLegacyHandlers struct {
+	Msg string
+}
+
+func (e *errNoLegacyHandlers) Error() string {
+	return fmt.Sprintf("legacy pipeline found no existing handlers: %s", e.Msg)
+}
+
+func (e *errNoLegacyHandlers) MisconfiguredPipeline() {}

backend/pipeline/adapterv1.go

@@ -285,6 +285,12 @@ func (a *AdapterV1) generateLegacyPipeline(ctx context.Context, event *corev2.Ev
 		return nil, err
 	}
 
+	if len(handlers) < 1 {
+		return nil, &errNoLegacyHandlers{
+			Msg: fmt.Sprintf("none of %s exist", legacyHandlerNames),
+		}
+	}
+
 	pipeline := &corev2.Pipeline{
 		ObjectMeta: corev2.ObjectMeta{
 			Name:      LegacyPipelineName,

backend/pipeline/adapterv1_test.go

@@ -535,17 +535,62 @@ func TestAdapterV1_resolvePipelineReference(t *testing.T) {
 				},
 				event: func() *corev2.Event {
 					event := corev2.FixtureEvent("entity1", "check1")
+					event.Check.Handlers = []string{"myhandler"}
 					return event
 				}(),
 			},
+			fields: fields{
+				Store: func() store.Store {
+					handler := &corev2.Handler{
+						ObjectMeta: corev2.NewObjectMeta("myhandler", "default"),
+					}
+					stor := &mockstore.MockStore{}
+					stor.On("GetHandlerByName", mock.Anything, handler.GetName()).
+						Return(handler, nil)
+					return stor
+				}(),
+			},
 			want: func() *corev2.Pipeline {
 				pipeline := &corev2.Pipeline{
 					ObjectMeta: corev2.NewObjectMeta("legacy-pipeline", "default"),
-					Workflows:  []*corev2.PipelineWorkflow{},
+					Workflows: []*corev2.PipelineWorkflow{
+						{
+							Name: "legacy-pipeline-workflow-myhandler",
+							Handler: &corev2.ResourceReference{
+								Type:       "Handler",
+								APIVersion: "core/v2",
+								Name:       "myhandler",
+							},
+						},
+					},
 				}
 				return pipeline
 			}(),
 		},
+		{
+			name: "returns error when ref name is legacy-pipeline but no handlers exist",
+			args: args{
+				ctx: context.WithValue(context.Background(), corev2.NamespaceKey, "default"),
+				ref: &corev2.ResourceReference{
+					Name: "legacy-pipeline",
+				},
+				event: func() *corev2.Event {
+					event := corev2.FixtureEvent("entity1", "check1")
+					event.Check.Handlers = []string{"myhandler"}
+					return event
+				}(),
+			},
+			fields: fields{
+				Store: func() store.Store {
+					var missingHandler *corev2.Handler
+					stor := &mockstore.MockStore{}
+					stor.On("GetHandlerByName", mock.Anything, mock.Anything).
+						Return(missingHandler, nil)
+					return stor
+				}(),
+			},
+			wantErr: true,
+		},
 		{
 			name: "returns a stored pipeline if the ref name is not legacy-pipeline",
 			args: args{

backend/pipelined/pipelined.go

@@ -248,11 +248,14 @@ func (p *Pipelined) handleMessage(ctx context.Context, msg interface{}) (hadPipe
 						return true, err
 					}
 					skipPipelineErr := fmt.Errorf("%w, skipping execution of pipeline", err)
-					if _, ok := err.(*pipeline.ErrNoWorkflows); ok {
-						if fields["check_name"] != "keepalive" {
-							// only warn about empty pipelines if it's not a keepalive.
-							// this reduces log spam.
-							logger.WithFields(fields).Warn(skipPipelineErr)
+					if _, ok := err.(pipeline.ErrMisconfiguredPipeline); ok {
+						if fields["check_name"] == "keepalive" {
+							// supress logging for keepalive events to debug.
+							// default "keepalive" handler is added to keepalive events
+							// which frequently generates log noise.
+							logger.WithFields(fields).Debug(skipPipelineErr)
+						} else {
+							logger.WithFields(fields).Info(skipPipelineErr)
 						}
 					} else {
 						logger.WithFields(fields).Error(skipPipelineErr)