Fix stack deploy re-deploying service after --force

When updating a service with the `--force` option, the `ForceUpdate`
property of the taskspec is incremented.

Stack deploy did not take this into account, and reset this
field to its default value (0), causing the service to be
re-deployed.

This patch copies the existing value before updating the service.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/stack/swarm/deploy_composefile.go

@@ -249,6 +249,12 @@ func deployServices(
 				// service update.
 				serviceSpec.TaskTemplate.ContainerSpec.Image = service.Spec.TaskTemplate.ContainerSpec.Image
 			}
+
+			// Stack deploy does not have a `--force` option. Preserve existing ForceUpdate
+			// value so that tasks are not re-deployed if not updated.
+			// TODO move this to API client?
+			serviceSpec.TaskTemplate.ForceUpdate = service.Spec.TaskTemplate.ForceUpdate
+
 			response, err := apiClient.ServiceUpdate(
 				ctx,
 				service.ID,

cli/command/stack/swarm/deploy_test.go

@@ -27,7 +27,8 @@ func TestPruneServices(t *testing.T) {
 }
 
 // TestServiceUpdateResolveImageChanged tests that the service's
-// image digest is preserved if the image did not change in the compose file
+// image digest, and "ForceUpdate" is preserved if the image did not change in
+// the compose file
 func TestServiceUpdateResolveImageChanged(t *testing.T) {
 	namespace := convert.NewNamespace("mystack")
 
@@ -49,6 +50,7 @@ func TestServiceUpdateResolveImageChanged(t *testing.T) {
 							ContainerSpec: &swarm.ContainerSpec{
 								Image: "foobar:1.2.3@sha256:deadbeef",
 							},
+							ForceUpdate: 123,
 						},
 					},
 				},
@@ -65,18 +67,21 @@ func TestServiceUpdateResolveImageChanged(t *testing.T) {
 		image                 string
 		expectedQueryRegistry bool
 		expectedImage         string
+		expectedForceUpdate   uint64
 	}{
 		// Image not changed
 		{
 			image: "foobar:1.2.3",
 			expectedQueryRegistry: false,
 			expectedImage:         "foobar:1.2.3@sha256:deadbeef",
+			expectedForceUpdate:   123,
 		},
 		// Image changed
 		{
 			image: "foobar:1.2.4",
 			expectedQueryRegistry: true,
 			expectedImage:         "foobar:1.2.4",
+			expectedForceUpdate:   123,
 		},
 	}
 
@@ -95,8 +100,9 @@ func TestServiceUpdateResolveImageChanged(t *testing.T) {
 		}
 		err := deployServices(ctx, client, spec, namespace, false, ResolveImageChanged)
 		assert.NilError(t, err)
-		assert.Check(t, is.Equal(testcase.expectedQueryRegistry, receivedOptions.QueryRegistry))
-		assert.Check(t, is.Equal(testcase.expectedImage, receivedService.TaskTemplate.ContainerSpec.Image))
+		assert.Check(t, is.Equal(receivedOptions.QueryRegistry, testcase.expectedQueryRegistry))
+		assert.Check(t, is.Equal(receivedService.TaskTemplate.ContainerSpec.Image, testcase.expectedImage))
+		assert.Check(t, is.Equal(receivedService.TaskTemplate.ForceUpdate, testcase.expectedForceUpdate))
 
 		receivedService = swarm.ServiceSpec{}
 		receivedOptions = types.ServiceUpdateOptions{}