From f28ad350bdd82c7b60a990b37a513233b30b92f7 Mon Sep 17 00:00:00 2001
From: Paul Bellamy <paul.a.bellamy@gmail.com>
Date: Fri, 20 Nov 2015 12:39:57 +0000
Subject: [PATCH] make weave and the proxy work with tcp-only dockers via
 DOCKER_HOST

---
 common/docker/client.go |  8 ++++++++
 prog/weaver/main.go     |  8 +++++++-
 weave                   | 16 ++++++++++++----
 3 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/common/docker/client.go b/common/docker/client.go
index bd4b78f6..0a823690 100644
--- a/common/docker/client.go
+++ b/common/docker/client.go
@@ -2,6 +2,8 @@ package docker
 
 import (
 	"errors"
+	"strings"
+
 	"github.com/fsouza/go-dockerclient"
 
 	. "github.com/weaveworks/weave/common"
@@ -19,6 +21,9 @@ type Client struct {
 
 // NewClient creates a new Docker client and checks we can talk to Docker
 func NewClient(apiPath string) (*Client, error) {
+	if apiPath != "" && !strings.Contains(apiPath, "://") {
+		apiPath = "tcp://" + apiPath
+	}
 	dc, err := docker.NewClient(apiPath)
 	if err != nil {
 		return nil, err
@@ -29,6 +34,9 @@ func NewClient(apiPath string) (*Client, error) {
 }
 
 func NewVersionedClient(apiPath string, apiVersionString string) (*Client, error) {
+	if !strings.Contains(apiPath, "://") {
+		apiPath = "tcp://" + apiPath
+	}
 	dc, err := docker.NewVersionedClient(apiPath, apiVersionString)
 	if err != nil {
 		return nil, err
diff --git a/prog/weaver/main.go b/prog/weaver/main.go
index 51acd0c3..a4ff46e8 100644
--- a/prog/weaver/main.go
+++ b/prog/weaver/main.go
@@ -70,8 +70,14 @@ func main() {
 		iface                     *net.Interface
 		datapathName              string
 		trustedSubnetStr          string
+
+		defaultDockerHost = "unix:///var/run/docker.sock"
 	)
 
+	if val := os.Getenv("DOCKER_HOST"); val != "" {
+		defaultDockerHost = val
+	}
+
 	mflag.BoolVar(&justVersion, []string{"#version", "-version"}, false, "print version and exit")
 	mflag.BoolVar(&createDatapath, []string{"-create-datapath"}, false, "create ODP datapath and exit")
 	mflag.BoolVar(&deleteDatapath, []string{"-delete-datapath"}, false, "delete ODP datapath and exit")
@@ -93,7 +99,7 @@ func main() {
 	mflag.StringVar(&iprangeCIDR, []string{"#iprange", "#-iprange", "-ipalloc-range"}, "", "IP address range reserved for automatic allocation, in CIDR notation")
 	mflag.StringVar(&ipsubnetCIDR, []string{"#ipsubnet", "#-ipsubnet", "-ipalloc-default-subnet"}, "", "subnet to allocate within by default, in CIDR notation")
 	mflag.IntVar(&peerCount, []string{"#initpeercount", "#-initpeercount", "-init-peer-count"}, 0, "number of peers in network (for IP address allocation)")
-	mflag.StringVar(&dockerAPI, []string{"#api", "#-api", "-docker-api"}, "", "Docker API endpoint, e.g. unix:///var/run/docker.sock")
+	mflag.StringVar(&dockerAPI, []string{"#api", "#-api", "-docker-api"}, defaultDockerHost, "Docker API endpoint")
 	mflag.BoolVar(&noDNS, []string{"-no-dns"}, false, "disable DNS server")
 	mflag.StringVar(&dnsDomain, []string{"-dns-domain"}, nameserver.DefaultDomain, "local domain to server requests for")
 	mflag.StringVar(&dnsListenAddress, []string{"-dns-listen-address"}, nameserver.DefaultListenAddress, "address to listen on for DNS requests")
diff --git a/weave b/weave
index 27abdf1f..01becaf2 100755
--- a/weave
+++ b/weave
@@ -97,15 +97,19 @@ usage() {
 }
 
 docker_sock() {
+  if [ -z "$DOCKER_HOST" ]; then
+    echo "/var/run/docker.sock"
+    return
+  fi
   if echo "$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://$(docker_sock)"
+  if [ -n "$(docker_sock)" ]; then
+    echo "-v $(docker_sock):$(docker_sock)"
+  fi
 }
 
 exec_remote() {
@@ -125,6 +129,7 @@ exec_remote() {
         -e WEAVE_NO_FASTDP \
         -e WEAVE_NO_BRIDGED_FASTDP \
         -e WEAVE_NO_PLUGIN \
+        -e DOCKER_HOST \
         -e DOCKER_BRIDGE \
         -e DOCKER_CLIENT_HOST="$DOCKER_CLIENT_HOST" \
         -e DOCKER_CLIENT_ARGS \
@@ -1624,6 +1629,7 @@ launch_router() {
         $(docker_sock_volume_mount) \
         -p $PORT:$CONTAINER_PORT/tcp -p $PORT:$CONTAINER_PORT/udp \
         ${NETHOST_OPT:-$DNS_PORT_MAPPING} \
+        -e DOCKER_HOST \
         -e WEAVE_PASSWORD \
         -e WEAVE_CIDR=none \
         $WEAVE_DOCKER_ARGS $IMAGE $COVERAGE_ARGS \
@@ -1633,7 +1639,7 @@ 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://$(docker_sock)" "$@")
+        "$@")
     with_container_netns_or_die $CONTAINER_NAME setup_router_iface_$BRIDGE_TYPE
     attach_router
 }
@@ -1683,6 +1689,7 @@ launch_proxy() {
         -v /proc:/hostproc \
         -e PROCFS=/hostproc \
         -e WEAVE_CIDR=none \
+        -e DOCKER_HOST \
         -e DOCKER_BRIDGE \
         -e WEAVE_DEBUG \
         -e COVERAGE \
@@ -1703,6 +1710,7 @@ launch_plugin() {
         --net=host \
         $(docker_sock_volume_mount) \
         -v /run/docker/plugins:/run/docker/plugins \
+        -e DOCKER_HOST \
         $PLUGIN_IMAGE "$@")
 }