Bool flag using convention. Tweak usage.

docs/cmd/kn_service_update.md

@@ -47,10 +47,10 @@ kn service update NAME [flags]
   -l, --label stringArray        Service label to set. name=value; you may provide this flag any number of times to set multiple labels. To unset, specify the label name followed by a "-" (e.g., name-).
       --limits-cpu string        The limits on the requested CPU (e.g., 1000m).
       --limits-memory string     The limits on the requested memory (e.g., 1024Mi).
-      --lock-to-digest           When not updating the image field, make sure the image we're running doesn't change by locking it to the currently-running image digest. (default true)
       --max-scale int            Maximal number of replicas.
       --min-scale int            Minimal number of replicas.
   -n, --namespace string         List the requested object(s) in given namespace.
+      --no-lock-to-digest        do not set the image to the latest revision's image digest. If you specify --image, the image will always be set to the provided value, regardless.
   -p, --port int32               The port where application listens on.
       --requests-cpu string      The requested CPU (e.g., 250m).
       --requests-memory string   The requested memory (e.g., 64Mi).

pkg/kn/commands/service/configuration_edit_flags.go

@@ -21,6 +21,7 @@ import (
 	"github.com/spf13/cobra"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
+	"knative.dev/client/pkg/kn/flags"
 	servinglib "knative.dev/client/pkg/serving"
 	util "knative.dev/client/pkg/util"
 	servingv1alpha1 "knative.dev/serving/pkg/apis/serving/v1alpha1"
@@ -107,11 +108,9 @@ func (p *ConfigurationEditFlags) addSharedFlags(command *cobra.Command) {
 // AddUpdateFlags adds the flags specific to update.
 func (p *ConfigurationEditFlags) AddUpdateFlags(command *cobra.Command) {
 	p.addSharedFlags(command)
-	command.Flags().BoolVar(&p.LockToDigest, "lock-to-digest", true,
-		"When not updating the image field, make sure the image we're running doesn't "+
-			"change by locking it to the currently-running image digest.")
-	// Don't add it to p.flags, it doesn't affect anything on its own.
-
+	flags.AddBothBoolFlags(command.Flags(), &p.LockToDigest, "lock-to-digest", "", true,
+		"set the image to the latest revision's image digest. If you specify --image, the image will always be set to the provided value, regardless.")
+	// Don't mark as changing the revision.
 }
 
 // AddCreateFlags adds the flags specific to create

pkg/kn/commands/service/service_update_test.go

@@ -38,9 +38,9 @@ import (
 	"knative.dev/serving/pkg/apis/serving/v1alpha1"
 )
 
-var exampleImageByDigest string = "gcr.io/foo/bar@sha256:deadbeefdeadbeef"
-var exampleRevisionName string = "foo-asdf"
-var exampleRevisionName2 string = "foo-xyzzy"
+var exampleImageByDigest = "gcr.io/foo/bar@sha256:deadbeefdeadbeef"
+var exampleRevisionName = "foo-asdf"
+var exampleRevisionName2 = "foo-xyzzy"
 
 func fakeServiceUpdate(original *v1alpha1.Service, args []string, sync bool) (
 	action client_testing.Action,
@@ -357,6 +357,7 @@ func TestServiceUpdateEnv(t *testing.T) {
 
 	template, err = servinglib.RevisionTemplateOfService(updated)
 	assert.NilError(t, err)
+	// Test that we pinned to digest
 	assert.Equal(t, template.Spec.Containers[0].Image, exampleImageByDigest)
 	assert.Equal(t, template.Spec.Containers[0].Env[0], expectedEnvVar)
 }