From edc996860496f63b8e4eb786890e8ba2bab7e875 Mon Sep 17 00:00:00 2001
From: Solomon Hykes <solomon@dotcloud.com>
Date: Mon, 4 Feb 2013 23:25:28 -0800
Subject: [PATCH] Clearer error message in the client when DOCKER env variable
 is not set

---
 docker/docker.go | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/docker/docker.go b/docker/docker.go
index 3c3da5e378..e919ec14c7 100644
--- a/docker/docker.go
+++ b/docker/docker.go
@@ -8,6 +8,7 @@ import (
 	"os"
 	"syscall"
 	"unsafe"
+	"fmt"
 )
 
 
@@ -160,6 +161,10 @@ func Fatal(err error) {
 
 func main() {
 	var err error
+	if os.Getenv("DOCKER") == "" {
+		fmt.Printf("Can't connect. Please set environment variable DOCKER to ip:port, eg. 'localhost:4242'.\n")
+		os.Exit(1)
+	}
 	if IsTerminal(0) && os.Getenv("NORAW") == "" {
 		oldState, err = MakeRaw(0)
 		if err != nil {