add flag --no-push (#21)

cmd/kaniko-docker/main.go

@@ -127,6 +127,11 @@ func main() {
 			Usage:  "Artifact file location that will be generated by the plugin. This file will include information of docker images that are uploaded by the plugin.",
 			EnvVar: "PLUGIN_ARTIFACT_FILE",
 		},
+		cli.BoolFlag{
+			Name:   "no-push",
+			Usage:  "Set this flag if you only want to build the image, without pushing to a registry",
+			EnvVar: "PLUGIN_NO_PUSH",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -155,6 +160,7 @@ func run(c *cli.Context) error {
 			CacheRepo:     c.String("cache-repo"),
 			CacheTTL:      c.Int("cache-ttl"),
 			DigestFile:    defaultDigestFile,
+			NoPush:        c.Bool("no-push"),
 		},
 		Artifact: kaniko.Artifact{
 			Tags:         c.StringSlice("tags"),

cmd/kaniko-ecr/main.go

@@ -117,6 +117,11 @@ func main() {
 			Usage:  "Artifact file location that will be generated by the plugin. This file will include information of docker images that are uploaded by the plugin.",
 			EnvVar: "PLUGIN_ARTIFACT_FILE",
 		},
+		cli.BoolFlag{
+			Name:   "no-push",
+			Usage:  "Set this flag if you only want to build the image, without pushing to a registry",
+			EnvVar: "PLUGIN_NO_PUSH",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -144,6 +149,7 @@ func run(c *cli.Context) error {
 			CacheRepo:    fmt.Sprintf("%s/%s", c.String("registry"), c.String("cache-repo")),
 			CacheTTL:     c.Int("cache-ttl"),
 			DigestFile:   defaultDigestFile,
+			NoPush:       c.Bool("no-push"),
 		},
 		Artifact: kaniko.Artifact{
 			Tags:         c.StringSlice("tags"),

cmd/kaniko-gcr/main.go

@@ -113,6 +113,11 @@ func main() {
 			Usage:  "Artifact file location that will be generated by the plugin. This file will include information of docker images that are uploaded by the plugin.",
 			EnvVar: "PLUGIN_ARTIFACT_FILE",
 		},
+		cli.BoolFlag{
+			Name:   "no-push",
+			Usage:  "Set this flag if you only want to build the image, without pushing to a registry",
+			EnvVar: "PLUGIN_NO_PUSH",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -144,6 +149,7 @@ func run(c *cli.Context) error {
 			CacheRepo:    fmt.Sprintf("%s/%s", c.String("registry"), c.String("cache-repo")),
 			CacheTTL:     c.Int("cache-ttl"),
 			DigestFile:   defaultDigestFile,
+			NoPush:       c.Bool("no-push"),
 		},
 		Artifact: kaniko.Artifact{
 			Tags:         c.StringSlice("tags"),

kaniko.go

@@ -26,6 +26,7 @@ type (
 		CacheRepo     string   // Remote repository that will be used to store cached layers
 		CacheTTL      int      // Cache timeout in hours
 		DigestFile    string   // Digest file location
+		NoPush        bool     // Set this flag if you only want to build the image, without pushing to a registry
 	}
 	// Artifact defines content of artifact file
 	Artifact struct {
@@ -34,7 +35,6 @@ type (
 		Registry     string                    // Docker artifact registry
 		RegistryType artifact.RegistryTypeEnum // Rocker artifact registry type
 		ArtifactFile string                    // Artifact file location
-
 	}
 
 	// Plugin defines the Docker plugin parameters.
@@ -100,6 +100,10 @@ func (p Plugin) Exec() error {
 		cmdArgs = append(cmdArgs, fmt.Sprintf("--digest-file=%s", p.Build.DigestFile))
 	}
 
+	if p.Build.NoPush {
+		cmdArgs = append(cmdArgs, fmt.Sprintf("--no-push"))
+	}
+
 	cmd := exec.Command("/kaniko/executor", cmdArgs...)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr