First pass at passing DOCKER_HOST=unix://* through to the weave and proxy

prog/weaveproxy/main.go

@@ -12,7 +12,8 @@ import (
 )
 
 var (
-	version = "(unreleased version)"
+	version           = "(unreleased version)"
+	defaultDockerHost = "unix:///var/run/docker.sock"
 )
 
 func main() {
@@ -61,6 +62,11 @@ func main() {
 	Log.Infoln("weave proxy", version)
 	Log.Infoln("Command line arguments:", strings.Join(os.Args[1:], " "))
 
+	c.DockerHost = defaultDockerHost
+	if dockerHost := os.Getenv("DOCKER_HOST"); dockerHost != "" {
+		c.DockerHost = dockerHost
+	}
+
 	p, err := proxy.NewProxy(c)
 	if err != nil {
 		Log.Fatalf("Could not start proxy: %s", err)

proxy/common.go

@@ -39,6 +39,7 @@ func callWeave(args ...string) ([]byte, []byte, error) {
 	}
 
 	propagateEnv("DOCKER_BRIDGE")
+	propagateEnv("DOCKER_HOST")
 
 	// Propogage WEAVE_DEBUG, to make debugging easier.
 	propagateEnv("WEAVE_DEBUG")

proxy/proxy.go

@@ -25,8 +25,6 @@ const (
 	defaultCaFile   = "ca.pem"
 	defaultKeyFile  = "key.pem"
 	defaultCertFile = "cert.pem"
-	dockerSock      = "/var/run/docker.sock"
-	dockerSockUnix  = "unix://" + dockerSock
 
 	weaveSock     = "/var/run/weave/weave.sock"
 	weaveSockUnix = "unix://" + weaveSock
@@ -61,6 +59,7 @@ type Config struct {
 	WithDNS             bool
 	WithoutDNS          bool
 	NoMulticastRoute    bool
+	DockerHost          string
 }
 
 type wait struct {
@@ -94,7 +93,7 @@ func NewProxy(c Config) (*Proxy, error) {
 	// to insulate ourselves from breaking changes to the API, as
 	// happened in 1.20 (Docker 1.8.0) when the presentation of
 	// volumes changed in `inspect`.
-	client, err := weavedocker.NewVersionedClient(dockerSockUnix, "1.18")
+	client, err := weavedocker.NewVersionedClient(c.DockerHost, "1.18")
 	if err != nil {
 		return nil, err
 	}
@@ -140,7 +139,16 @@ func (proxy *Proxy) AttachExistingContainers() {
 }
 
 func (proxy *Proxy) Dial() (net.Conn, error) {
-	return net.Dial("unix", dockerSock)
+	proto := "tcp"
+	addr := proxy.Config.DockerHost
+	switch {
+	case strings.HasPrefix(addr, "unix://"):
+		proto = "unix"
+		addr = strings.TrimPrefix(addr, "unix://")
+	case strings.HasPrefix(addr, "tcp://"):
+		addr = strings.TrimPrefix(addr, "tcp://")
+	}
+	return net.Dial(proto, addr)
 }
 
 func (proxy *Proxy) findWeaveWaitVolumes() error {
@@ -321,8 +329,10 @@ func (proxy *Proxy) listen(protoAndAddr string) (net.Listener, string, error) {
 		if err != nil {
 			return nil, "", err
 		}
-		if err = copyOwnerAndPermissions(dockerSock, addr); err != nil {
-			return nil, "", err
+		if strings.HasPrefix(proxy.Config.DockerHost, "unix://") {
+			if err = copyOwnerAndPermissions(strings.TrimPrefix(proxy.Config.DockerHost, "unix://"), addr); err != nil {
+				return nil, "", err
+			}
 		}
 
 	default:

weave

@@ -96,9 +96,21 @@ usage() {
     exit 1
 }
 
+docker_sock() {
+  if echo "$DOCKER_HOST" | grep -q "^unix://" >/dev/null; then
+    echo "${DOCKER_HOST#unix://}"
+  else
+    echo "/var/run/docker.sock"
+  fi
+}
+
+docker_sock_volume_mount() {
+  echo "-v $(docker_sock):$(docker_sock) -e DOCKER_HOST=unix://$(docker_sock)"
+}
+
 exec_remote() {
     docker $DOCKER_CLIENT_ARGS run --rm --privileged --net=host \
-        -v /var/run/docker.sock:/var/run/docker.sock \
+        $(docker_sock_volume_mount) \
         -v /proc:/hostproc \
         -e PROCFS=/hostproc \
         -e DOCKERHUB_USER="$DOCKERHUB_USER" \
@@ -1609,7 +1621,7 @@ launch_router() {
     # additional parameters, such as resource limits, to docker
     # when launching the weave container.
     ROUTER_CONTAINER=$(docker run --privileged -d --name=$CONTAINER_NAME \
-        -v /var/run/docker.sock:/var/run/docker.sock \
+        $(docker_sock_volume_mount) \
         -p $PORT:$CONTAINER_PORT/tcp -p $PORT:$CONTAINER_PORT/udp \
         ${NETHOST_OPT:-$DNS_PORT_MAPPING} \
         -e WEAVE_PASSWORD \
@@ -1621,7 +1633,7 @@ launch_router() {
         --dns-effective-listen-address $DOCKER_BRIDGE_IP \
         ${NETHOST_OPT:+$DNS_ROUTER_OPTS} $NO_DNS_OPT \
         --http-addr $HTTP_IP:$HTTP_PORT \
-        --docker-api "unix:///var/run/docker.sock" "$@")
+        --docker-api "unix://$(docker_sock)" "$@")
     with_container_netns_or_die $CONTAINER_NAME setup_router_iface_$BRIDGE_TYPE
     attach_router
 }
@@ -1666,7 +1678,7 @@ launch_proxy() {
     mkdir -p /var/run/weave
     PROXY_CONTAINER=$(docker run --privileged -d --name=$PROXY_CONTAINER_NAME --net=host \
         $PROXY_VOLUMES \
-        -v /var/run/docker.sock:/var/run/docker.sock \
+        $(docker_sock_volume_mount) \
         -v /var/run/weave:/var/run/weave \
         -v /proc:/hostproc \
         -e PROCFS=/hostproc \
@@ -1689,7 +1701,7 @@ launch_plugin() {
     PLUGIN_CONTAINER=$(docker run --privileged -d --name=$PLUGIN_CONTAINER_NAME \
         --restart=always \
         --net=host \
-        -v /var/run/docker.sock:/var/run/docker.sock \
+        $(docker_sock_volume_mount) \
         -v /run/docker/plugins:/run/docker/plugins \
         $PLUGIN_IMAGE "$@")
 }