Add support for custom platform

cmd/kaniko-docker/main.go

@@ -145,6 +145,11 @@ func main() {
 			Usage:  "Set this flag with value as oneof <panic|fatal|error|warn|info|debug|trace> to set the logging level for kaniko. Defaults to info.",
 			EnvVar: "PLUGIN_VERBOSITY",
 		},
+		cli.StringFlag{
+			Name:   "platform",
+			Usage:  "Allows to build with another default platform than the host, similarly to docker build --platform",
+			EnvVar: "PLUGIN_PLATFORM",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -181,6 +186,7 @@ func run(c *cli.Context) error {
 			DigestFile:    defaultDigestFile,
 			NoPush:        noPush,
 			Verbosity:     c.String("verbosity"),
+			Platform:      c.String("platform"),
 		},
 		Artifact: kaniko.Artifact{
 			Tags:         c.StringSlice("tags"),

cmd/kaniko-ecr/main.go

@@ -174,6 +174,11 @@ func main() {
 			Usage:  "Set this flag with value as oneof <panic|fatal|error|warn|info|debug|trace> to set the logging level for kaniko. Defaults to info.",
 			EnvVar: "PLUGIN_VERBOSITY",
 		},
+		cli.StringFlag{
+			Name:   "platform",
+			Usage:  "Allows to build with another default platform than the host, similarly to docker build --platform",
+			EnvVar: "PLUGIN_PLATFORM",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -252,6 +257,7 @@ func run(c *cli.Context) error {
 			DigestFile:   defaultDigestFile,
 			NoPush:       noPush,
 			Verbosity:    c.String("verbosity"),
+			Platform:     c.String("platform"),
 		},
 		Artifact: kaniko.Artifact{
 			Tags:         c.StringSlice("tags"),

cmd/kaniko-gcr/main.go

@@ -130,6 +130,11 @@ func main() {
 			Usage:  "Set this flag as --verbosity=<panic|fatal|error|warn|info|debug|trace> to set the logging level for kaniko. Defaults to info.",
 			EnvVar: "PLUGIN_VERBOSITY",
 		},
+		cli.StringFlag{
+			Name:   "platform",
+			Usage:  "Allows to build with another default platform than the host, similarly to docker build --platform",
+			EnvVar: "PLUGIN_PLATFORM",
+		},
 	}
 
 	if err := app.Run(os.Args); err != nil {
@@ -167,6 +172,7 @@ func run(c *cli.Context) error {
 			DigestFile:   defaultDigestFile,
 			NoPush:       noPush,
 			Verbosity:    c.String("verbosity"),
+			Platform:     c.String("platform"),
 		},
 		Artifact: kaniko.Artifact{
 			Tags:         c.StringSlice("tags"),

kaniko.go

@@ -30,6 +30,7 @@ type (
 		DigestFile    string   // Digest file location
 		NoPush        bool     // Set this flag if you only want to build the image, without pushing to a registry
 		Verbosity     string   // Log level
+		Platform      string   // Allows to build with another default platform than the host, similarly to docker build --platform
 	}
 
 	// Artifact defines content of artifact file
@@ -157,6 +158,10 @@ func (p Plugin) Exec() error {
 		cmdArgs = append(cmdArgs, fmt.Sprintf("--verbosity=%s", p.Build.Verbosity))
 	}
 
+	if p.Build.Platform != "" {
+		cmdArgs = append(cmdArgs, fmt.Sprintf("--customPlatform=%s", p.Build.Platform))
+	}
+
 	cmd := exec.Command("/kaniko/executor", cmdArgs...)
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr