Merge pull request #30 from rancher/feature/custom-image-flag

[Feature] add --image/-i flag to specify custom k3s image/tag (start deprecation of --version flag)

cli/commands.go

@@ -23,6 +23,8 @@ import (
 	"github.com/urfave/cli"
 )
 
+const defaultRegistry = "docker.io"
+
 // CheckTools checks if the docker API server is responding
 func CheckTools(c *cli.Context) error {
 	log.Print("Checking docker...")
@@ -43,6 +45,24 @@ func CheckTools(c *cli.Context) error {
 // CreateCluster creates a new single-node cluster container and initializes the cluster directory
 func CreateCluster(c *cli.Context) error {
 
+	// define image
+	image := c.String("image")
+	if c.IsSet("version") {
+		// TODO: --version to be deprecated
+		log.Println("[WARNING] The `--version` flag will be deprecated soon, please use `--image rancher/k3s:<version>` instead")
+		if c.IsSet("image") {
+			// version specified, custom image = error (to push deprecation of version flag)
+			log.Fatalln("[ERROR] Please use `--image <image>:<version>` instead of --image and --version")
+		} else {
+			// version specified, default image = ok (until deprecation of version flag)
+			image = fmt.Sprintf("%s:%s", strings.Split(image, ":")[0], c.String("version"))
+		}
+	}
+	if len(strings.Split(image, "/")) <= 2 {
+		// fallback to default registry
+		image = fmt.Sprintf("%s/%s", defaultRegistry, image)
+	}
+
 	// create cluster network
 	networkID, err := createClusterNetwork(c.String("name"))
 	if err != nil {
@@ -75,7 +95,7 @@ func CreateCluster(c *cli.Context) error {
 	log.Printf("Creating cluster [%s]", c.String("name"))
 	dockerID, err := createServer(
 		c.GlobalBool("verbose"),
-		fmt.Sprintf("docker.io/rancher/k3s:%s", c.String("version")),
+		image,
 		c.String("port"),
 		k3sServerArgs,
 		env,
@@ -137,7 +157,7 @@ func CreateCluster(c *cli.Context) error {
 		for i := 0; i < c.Int("workers"); i++ {
 			workerID, err := createWorker(
 				c.GlobalBool("verbose"),
-				fmt.Sprintf("docker.io/rancher/k3s:%s", c.String("version")),
+				image,
 				k3sWorkerArgs,
 				env,
 				c.String("name"),

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"fmt"
 	"log"
 	"os"
 
@@ -9,6 +10,9 @@ import (
 	"github.com/urfave/cli"
 )
 
+// defaultK3sImage specifies the default image being used for server and workers
+const defaultK3sImage = "docker.io/rancher/k3s"
+
 // main represents the CLI application
 func main() {
 
@@ -56,8 +60,8 @@ func main() {
 					Usage: "Mount one or more volumes into every node of the cluster (Docker notation: `source:destination[,source:destination]`)",
 				},
 				cli.StringFlag{
+					// TODO: to be deprecated
 					Name:  "version",
-					Value: version.GetK3sVersion(),
 					Usage: "Choose the k3s image version",
 				},
 				cli.IntFlag{
@@ -74,6 +78,11 @@ func main() {
 					Name:  "wait, w",
 					Usage: "Wait for the cluster to come up before returning",
 				},
+				cli.StringFlag{
+					Name:  "image, i",
+					Usage: "Specify a k3s image (Format: <repo>/<image>:<tag>)",
+					Value: fmt.Sprintf("%s:%s", defaultK3sImage, version.GetK3sVersion()),
+				},
 				cli.StringSliceFlag{
 					Name:  "server-arg, x",
 					Usage: "Pass an additional argument to k3s server (new flag per argument)",