From 1b8e015627992ea3bdf659291c596b87b898e4de Mon Sep 17 00:00:00 2001
From: Aanand Prasad <aanand.prasad@gmail.com>
Date: Thu, 19 Jun 2014 14:02:16 +0100
Subject: [PATCH] Implement OnLs

Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>
---
 backends/dockerclient.go | 15 ++++++---------
 beam/server.go           | 11 +++++++++++
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/backends/dockerclient.go b/backends/dockerclient.go
index 6947f08af6..a25350e7c4 100644
--- a/backends/dockerclient.go
+++ b/backends/dockerclient.go
@@ -46,7 +46,7 @@ func DockerClientWithConfig(config *DockerClientConfig) beam.Sender {
 		}
 		b.Server.OnVerb(beam.Attach, beam.Handler(b.attach))
 		b.Server.OnVerb(beam.Start, beam.Handler(b.start))
-		b.Server.OnVerb(beam.Ls, beam.Handler(b.ls))
+		b.Server.OnLs(b.ls)
 		b.Server.OnSpawn(b.spawn)
 		return b.Server, nil
 	})
@@ -86,28 +86,25 @@ func (b *dockerClientBackend) start(ctx *beam.Message) error {
 	return nil
 }
 
-func (b *dockerClientBackend) ls(ctx *beam.Message) error {
+func (b *dockerClientBackend) ls() ([]string, error) {
 	resp, err := b.client.call("GET", "/containers/json", "")
 	if err != nil {
-		return fmt.Errorf("get: %v", err)
+		return nil, fmt.Errorf("get: %v", err)
 	}
 	// FIXME: check for response error
 	c := engine.NewTable("Created", 0)
 	body, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
-		return fmt.Errorf("read body: %v", err)
+		return nil, fmt.Errorf("read body: %v", err)
 	}
 	if _, err := c.ReadListFrom(body); err != nil {
-		return fmt.Errorf("readlist: %v", err)
+		return nil, fmt.Errorf("readlist: %v", err)
 	}
 	names := []string{}
 	for _, env := range c.Data {
 		names = append(names, env.GetList("Names")[0][1:])
 	}
-	if _, err := ctx.Ret.Send(&beam.Message{Verb: beam.Set, Args: names}); err != nil {
-		return fmt.Errorf("send response: %v", err)
-	}
-	return nil
+	return names, nil
 }
 
 func (b *dockerClientBackend) spawn(cmd ...string) (beam.Sender, error) {
diff --git a/beam/server.go b/beam/server.go
index 11b91d9fdf..ecd4ebdaa6 100644
--- a/beam/server.go
+++ b/beam/server.go
@@ -27,6 +27,17 @@ func (s *Server) OnVerb(v Verb, h Sender) *Server {
 	return s
 }
 
+func (s *Server) OnLs(h func() ([]string, error)) *Server {
+	return s.OnVerb(Ls, Handler(func(msg *Message) error {
+		names, err := h()
+		if err != nil {
+			return err
+		}
+		_, err = msg.Ret.Send(&Message{Verb: Set, Args: names})
+		return err
+	}))
+}
+
 func (s *Server) OnSpawn(h func(cmd ...string) (Sender, error)) *Server {
 	return s.OnVerb(Spawn, Handler(func(msg *Message) error {
 		obj, err := h(msg.Args...)