[proxy] respect custom DOCKER_BRIDGE

proxy/common.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"os"
 	"os/exec"
 	"regexp"
 
@@ -22,7 +23,13 @@ func callWeave(args ...string) ([]byte, []byte, error) {
 	args = append([]string{"--local"}, args...)
 	Log.Debug("Calling weave", args)
 	cmd := exec.Command("./weave", args...)
-	cmd.Env = []string{"PROCFS=/hostproc", "PATH=/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"}
+	cmd.Env = []string{
+		"PATH=/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+		"PROCFS=/hostproc",
+	}
+	if bridge := os.Getenv("DOCKER_BRIDGE"); bridge != "" {
+		cmd.Env = append(cmd.Env, fmt.Sprintf("DOCKER_BRIDGE=%s", bridge))
+	}
 	var stdout, stderr bytes.Buffer
 	cmd.Stdout = &stdout
 	cmd.Stderr = &stderr

weave

@@ -1092,6 +1092,7 @@ launch_proxy() {
         -v /proc:/hostproc \
         -e PROCFS=/hostproc \
         -e WEAVE_CIDR=none \
+        -e DOCKER_BRIDGE \
         --entrypoint=/home/weave/weaveproxy \
         $WEAVEPROXY_DOCKER_ARGS $EXEC_IMAGE $PROXY_ARGS)
     wait_for_log $PROXY_CONTAINER_NAME "proxy listening"