Return partial mismatches in result

This means that the result is a Success but it still contains the error.

release/releaser_test.go

@@ -2,6 +2,7 @@ package release
 
 import (
 	"encoding/json"
+	"fmt"
 	"reflect"
 	"testing"
 	"time"
@@ -612,6 +613,7 @@ func Test_UpdateContainers(t *testing.T) {
 			Expected: map[bool]update.ControllerResult{
 				true: {
 					Status: update.ReleaseStatusSuccess,
+					Error:  fmt.Sprintf(update.ContainerTagMismatch, helloContainer),
 					PerContainer: []update.ContainerUpdate{
 						{
 							Container: sidecarContainer,
@@ -623,7 +625,7 @@ func Test_UpdateContainers(t *testing.T) {
 				false: {}, // Errors.
 			},
 			Commit: map[bool]string{
-				true:  "Release containers\n\ndefault:deployment/helloworld\n- weaveworks/sidecar:master-a000002\n",
+				true: "Release containers\n\ndefault:deployment/helloworld\n- weaveworks/sidecar:master-a000002\n",
 			},
 		},
 		{
@@ -641,7 +643,7 @@ func Test_UpdateContainers(t *testing.T) {
 				},
 			},
 			Expected: map[bool]update.ControllerResult{
-				true: {}, // Errors.
+				true:  {}, // Errors.
 				false: {}, // Errors.
 			},
 		},

update/containers.go

@@ -106,31 +106,44 @@ func (s ContainerSpecs) controllerUpdates(results Result, all []*ControllerUpdat
 
 		mismatchError := fmt.Sprintf(ContainerTagMismatch, strings.Join(mismatch, ", "))
 
+		var rerr string
+		skippedMismatches := s.SkipMismatches && len(mismatch) > 0
 		switch {
 		case len(notfound) > 0:
+			// Always fail if container disappeared or was misspelled
 			results[u.ResourceID] = ControllerResult{
 				Status: ReleaseStatusFailed,
 				Error:  fmt.Sprintf(ContainerNotFound, strings.Join(notfound, ", ")),
 			}
 		case !s.SkipMismatches && len(mismatch) > 0:
+			// Only fail if we do not skip for mismatches. Otherwise we either succeed
+			// with partial updates or then mark it as skipped because no precondition
+			// fulfilled.
 			results[u.ResourceID] = ControllerResult{
 				Status: ReleaseStatusFailed,
 				Error:  mismatchError,
 			}
 		case len(containerUpdates) == 0:
-			err := ImageUpToDate
-			if s.SkipMismatches && len(mismatch) > 0 {
-				err = mismatchError
+			rerr = ImageUpToDate
+			if skippedMismatches {
+				rerr = mismatchError
 			}
 			results[u.ResourceID] = ControllerResult{
 				Status: ReleaseStatusSkipped,
-				Error:  err,
+				Error:  rerr,
 			}
 		default:
+			rerr = ""
+			if skippedMismatches {
+				// While we succeed here, we still want the client to know that some
+				// container mismatched.
+				rerr = mismatchError
+			}
 			u.Updates = containerUpdates
 			updates = append(updates, u)
 			results[u.ResourceID] = ControllerResult{
 				Status:       ReleaseStatusSuccess,
+				Error:        rerr,
 				PerContainer: u.Updates,
 			}
 		}