From fd6d15e71268332c074f47db4c99da73c096b45f Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Thu, 20 Aug 2015 15:44:42 +0100
Subject: [PATCH] eliminate misleading flag parsing error

The standard mflags error reporting produces s.t. like
```
flag provided but not defined: -p
See '/home/weave/weaver --help'.
```
on stderr. This is misleading since the program name is container
local, so not something the user actually invoked.

Fixes #1321.
---
 prog/weaver/main.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/prog/weaver/main.go b/prog/weaver/main.go
index 7dcaa37d..8eb98e1f 100644
--- a/prog/weaver/main.go
+++ b/prog/weaver/main.go
@@ -87,7 +87,15 @@ func main() {
 	mflag.IntVar(&dnsTTL, []string{"-dns-ttl"}, nameserver.DefaultTTL, "TTL for DNS request from our domain")
 	mflag.DurationVar(&dnsClientTimeout, []string{"-dns-fallback-timeout"}, nameserver.DefaultClientTimeout, "timeout for fallback DNS requests")
 
+	// crude way of detecting that we probably have been started in a
+	// container, with `weave launch` --> suppress misleading paths in
+	// mflags error messages.
+	if os.Args[0] == "/home/weave/weaver" { // matches the Dockerfile ENTRYPOINT
+		os.Args[0] = "weave"
+		mflag.CommandLine.Init("weave", mflag.ExitOnError)
+	}
 	mflag.Parse()
+
 	peers = mflag.Args()
 
 	SetLogLevel(logLevel)