Make the docker endpoint a flag.

cmd/kubelet/kubelet.go

@@ -23,6 +23,7 @@ package main
 import (
 	"flag"
 	"math/rand"
+	"os"
 	"os/exec"
 	"time"
 
@@ -43,6 +44,7 @@ var (
 	address            = flag.String("address", "127.0.0.1", "The address for the info server to serve on")
 	port               = flag.Uint("port", 10250, "The port for the info server to serve on")
 	hostnameOverride   = flag.String("hostname_override", "", "If non-empty, will use this string as identification instead of the actual hostname.")
+	dockerEndpoint     = flag.String("docker_endpoint", "", "If non-empty, use this for the docker endpoint to communicate with")
 )
 
 const dockerBinary = "/usr/bin/docker"
@@ -56,7 +58,15 @@ func main() {
 	// Set up logger for etcd client
 	etcd.SetLogger(util.NewLogger("etcd "))
 
-	endpoint := "unix:///var/run/docker.sock"
+	var endpoint string
+	if len(*dockerEndpoint) > 0 {
+		endpoint = *dockerEndpoint
+	} else if len(os.Getenv("DOCKER_HOST")) > 0 {
+		endpoint = os.Getenv("DOCKER_HOST")
+	} else {
+		endpoint = "unix:///var/run/docker.sock"
+	}
+	glog.Infof("Connecting to docker on %s", endpoint)
 	dockerClient, err := docker.NewClient(endpoint)
 	if err != nil {
 		glog.Fatal("Couldn't connnect to docker.")
@@ -79,5 +89,5 @@ func main() {
 		SyncFrequency:      *syncFrequency,
 		HTTPCheckFrequency: *httpCheckFrequency,
 	}
-	my_kubelet.RunKubelet(*config, *manifestUrl, *etcdServers, *address, *port)
+	my_kubelet.RunKubelet(*config, *manifestUrl, *etcdServers, *address, *dockerEndpoint, *port)
 }