From 646fc9702ca43365be96ef2127be0bac8e0b0817 Mon Sep 17 00:00:00 2001
From: Elton Stoneman <elton@sixeyed.com>
Date: Tue, 23 May 2017 09:58:05 +0100
Subject: [PATCH] Add ARGs for cross-compiling

Add build args. Defaults to Linux/x64 so no change to existing image, but can build for other platforms - e.g.
```
docker build --build-arg GOOS=windows -t distribution-builder:windows .
```

Signed-off-by: Elton Stoneman <elton@sixeyed.com>
---
 Dockerfile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Dockerfile b/Dockerfile
index b0d06f12f..ac8dbca2f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,6 +3,9 @@ FROM golang:1.8-alpine
 ENV DISTRIBUTION_DIR /go/src/github.com/docker/distribution
 ENV DOCKER_BUILDTAGS include_oss include_gcs
 
+ARG GOOS=linux
+ARG GOARCH=amd64
+
 RUN set -ex \
     && apk add --no-cache make git