Add --container-runtime cli flag

cmd/kops/create_cluster.go

@@ -81,6 +81,7 @@ type CreateClusterOptions struct {
 	EtcdStorageType      string
 	Project              string
 	KubernetesVersion    string
+	ContainerRuntime     string
 	OutDir               string
 	Image                string
 	VPCID                string
@@ -183,6 +184,8 @@ func (o *CreateClusterOptions) InitDefaults() {
 	o.AdminAccess = []string{"0.0.0.0/0"}
 
 	o.Authorization = AuthorizationFlagRBAC
+
+	o.ContainerRuntime = "docker"
 }
 
 var (
@@ -298,6 +301,8 @@ func NewCmdCreateCluster(f *util.Factory, out io.Writer) *cobra.Command {
 	cmd.Flags().StringVar(&options.Project, "project", options.Project, "Project to use (must be set on GCE)")
 	cmd.Flags().StringVar(&options.KubernetesVersion, "kubernetes-version", options.KubernetesVersion, "Version of kubernetes to run (defaults to version in channel)")
 
+	cmd.Flags().StringVar(&options.ContainerRuntime, "container-runtime", options.ContainerRuntime, "Container runtime to use: containerd, docker")
+
 	cmd.Flags().StringVar(&sshPublicKey, "ssh-public-key", sshPublicKey, "SSH public key to use (defaults to ~/.ssh/id_rsa.pub on AWS)")
 
 	cmd.Flags().StringVar(&options.NodeSize, "node-size", options.NodeSize, "Set instance size for nodes")
@@ -989,6 +994,10 @@ func RunCreateCluster(f *util.Factory, out io.Writer, c *CreateClusterOptions) e
 		cluster.Spec.KubernetesVersion = c.KubernetesVersion
 	}
 
+	if c.ContainerRuntime != "" {
+		cluster.Spec.ContainerRuntime = c.ContainerRuntime
+	}
+
 	cluster.Spec.Networking = &api.NetworkingSpec{}
 	switch c.Networking {
 	case "classic":

docs/cli/kops_create_cluster.md

@@ -74,6 +74,7 @@ kops create cluster [flags]
       --channel string                   Channel for default versions and configuration to use (default "stable")
       --cloud string                     Cloud provider to use - gce, aws, vsphere, openstack
       --cloud-labels string              A list of KV pairs used to tag all instance groups in AWS (e.g. "Owner=John Doe,Team=Some Team").
+      --container-runtime string         Container runtime to use: containerd, docker (default "docker")
       --disable-subnet-tags              Set to disable automatic subnet tagging
       --dns string                       DNS hosted zone to use: public|private. (default "Public")
       --dns-zone string                  DNS hosted zone to use (defaults to longest matching zone)