From a23813061308fc076ef8f35731a5cd5bc44ea7af Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Wed, 20 Jan 2016 15:33:56 +0000
Subject: [PATCH] Give more explanation if we can't find weave to talk to

---
 plugin/ipam/driver.go | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/plugin/ipam/driver.go b/plugin/ipam/driver.go
index 8cd6142f..59273d73 100644
--- a/plugin/ipam/driver.go
+++ b/plugin/ipam/driver.go
@@ -1,10 +1,12 @@
 package ipamplugin
 
 import (
+	"fmt"
 	"net"
 
 	"github.com/docker/libnetwork/ipamapi"
 	"github.com/docker/libnetwork/netlabel"
+	godocker "github.com/fsouza/go-dockerclient"
 	"github.com/weaveworks/weave/api"
 	. "github.com/weaveworks/weave/common"
 	"github.com/weaveworks/weave/common/docker"
@@ -20,7 +22,13 @@ type ipam struct {
 }
 
 func NewIpam(client *docker.Client, version string) (ipamapi.Ipam, error) {
-	resolver := func() (string, error) { return client.GetContainerIP(WeaveContainer) }
+	resolver := func() (string, error) {
+		addr, err := client.GetContainerIP(WeaveContainer)
+		if _, ok := err.(*godocker.NoSuchContainer); ok {
+			return "", fmt.Errorf("%s container is not present. Have you launched it?", WeaveContainer)
+		}
+		return addr, err
+	}
 	return &ipam{client: client, weave: api.NewClientWithResolver(resolver)}, nil
 }