From 7cc53c4c6854c13a9e08fc3901753ba396161351 Mon Sep 17 00:00:00 2001
From: Paul Bellamy <paul.a.bellamy@gmail.com>
Date: Mon, 3 Aug 2015 12:28:17 +0100
Subject: [PATCH] [proxy] Handle case where no command is specified.

The docker daemon can't do this because we set /w/w.
---
 prog/weavewait/main.go                | 14 ++++++++------
 proxy/create_container_interceptor.go |  9 +++++++++
 test/610_proxy_wait_for_weave_test.sh |  5 +++++
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/prog/weavewait/main.go b/prog/weavewait/main.go
index 9b1151bf..d88e89f3 100644
--- a/prog/weavewait/main.go
+++ b/prog/weavewait/main.go
@@ -7,16 +7,14 @@ import (
 	"os/signal"
 	"syscall"
 
-	"github.com/weaveworks/weave/net"
+	weavenet "github.com/weaveworks/weave/net"
+	"github.com/weaveworks/weave/proxy"
 )
 
 func main() {
-	if len(os.Args) <= 1 {
-		os.Exit(0)
-	}
 	args := os.Args[1:]
 
-	if args[0] == "-s" {
+	if len(args) > 0 && args[0] == "-s" {
 		args = args[1:]
 	} else {
 		usr2 := make(chan os.Signal)
@@ -24,9 +22,13 @@ func main() {
 		<-usr2
 	}
 
-	_, err := net.EnsureInterface("ethwe", -1)
+	_, err := weavenet.EnsureInterface("ethwe", -1)
 	checkErr(err)
 
+	if len(args) == 0 {
+		checkErr(proxy.ErrNoCommandSpecified)
+	}
+
 	binary, err := exec.LookPath(args[0])
 	checkErr(err)
 
diff --git a/proxy/create_container_interceptor.go b/proxy/create_container_interceptor.go
index 5b6bfd7b..42b60ed1 100644
--- a/proxy/create_container_interceptor.go
+++ b/proxy/create_container_interceptor.go
@@ -3,6 +3,7 @@ package proxy
 import (
 	"bytes"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -15,6 +16,10 @@ import (
 
 const MaxDockerHostname = 64
 
+var (
+	ErrNoCommandSpecified = errors.New("No command specified")
+)
+
 type createContainerInterceptor struct{ proxy *Proxy }
 
 type createContainerRequestBody struct {
@@ -105,6 +110,10 @@ func (i *createContainerInterceptor) setWeaveWaitEntrypoint(container *docker.Co
 		}
 	}
 
+	if len(container.Entrypoint) == 0 && len(container.Cmd) == 0 {
+		return ErrNoCommandSpecified
+	}
+
 	if len(container.Entrypoint) == 0 || container.Entrypoint[0] != weaveWaitEntrypoint[0] {
 		container.Entrypoint = append(weaveWaitEntrypoint, container.Entrypoint...)
 	}
diff --git a/test/610_proxy_wait_for_weave_test.sh b/test/610_proxy_wait_for_weave_test.sh
index 1d5e1276..8abd4440 100755
--- a/test/610_proxy_wait_for_weave_test.sh
+++ b/test/610_proxy_wait_for_weave_test.sh
@@ -33,4 +33,9 @@ proxy docker_on $HOST1 create --name c4 -v /tmp/1:/srv1 -v /tmp/2:/srv2 -e 'WEAV
 proxy docker_on $HOST1 start -ai c4
 assert "docker_on $HOST1 inspect --format='{{range \$k, \$v := .Volumes}}{{\$k}} {{end}}' c4" "/srv1 /srv2 /w "
 
+# Check errors are returned (when docker returns an error code)
+assert_raises "docker -H tcp://$HOST1:12375 run -e 'WEAVE_CIDR=10.2.1.3/24' $SMALL_IMAGE foo 2>&1 | grep 'exec: \"foo\": executable file not found in \$PATH'"
+# Check errors still happen when no command is specified
+assert_raises "docker -H tcp://$HOST1:12375 run -e 'WEAVE_CIDR=10.2.1.3/24' $SMALL_IMAGE 2>&1 | grep 'Error response from daemon: No command specified'"
+
 end_suite