I wrote in a previous post how to run docker on antsle. After playing around with it, and trying a Dockerfile which uses multi-stage builds, I discovered that the version installed was 17.03 CE.

	myantsle ~ # docker version
	Client:
	 Version:      17.03.1-ce
	 API version:  1.27
	 Go version:   go1.8.3
	 Git commit:   c6d412e
	 Built:        Fri Aug  4 17:19:45 2017
	 OS/Arch:      linux/amd64

	Server:
	 Version:      17.03.1-ce
	 API version:  1.27 (minimum version 1.12)
	 Go version:   go1.8.3
	 Git commit:   c6d412e
	 Built:        Fri Aug  4 17:19:45 2017
	 OS/Arch:      linux/amd64
	 Experimental: false

This version doesn’t have multi-stage support, you need at least version 17.05, so I had to see if I could upgrade. Luckily there already is a package with a high enough version:

	myantsle ~ # equery meta app-emulation/docker
	 * app-emulation/docker [gentoo]
	Maintainer:  admwiggin@gmail.com (Tianon)
	Maintainer:  williamh@gentoo.org (William Hubbs)
	Maintainer:  mrueg@gentoo.org (Manuel Rüger)
	Upstream:    Remote-ID:   docker/docker ID: github
	Homepage:    https://dockerproject.org
	Location:    /usr/portage/app-emulation/docker
	Keywords:    17.03.1:0: amd64
	Keywords:    17.03.2:0:
	Keywords:    17.06.0-r1:0:
	Keywords:    17.06.1:0: ~amd64 ~arm
	Keywords:    9999:0:
	License:     Apache-2.0

So all I had to do was to run the upgrade and tell it which version I wanted

	myantsle ~ # emerge -aDuN =app-emulation/docker-17.06.1

And after that run

	myantsle ~ # etc-upgrade

Which got me docker version 17.06 CE

	myantsle ~ # docker version
	Client:
	 Version:      17.06.1-ce
	 API version:  1.30
	 Go version:   go1.8.3
	 Git commit:   874a737
	 Built:        Sat Sep  9 05:09:04 2017
	 OS/Arch:      linux/amd64

	Server:
	 Version:      17.06.1-ce
	 API version:  1.30 (minimum version 1.12)
	 Go version:   go1.8.3
	 Git commit:   874a737
	 Built:        Fri Sep  8 22:08:11 2017
	 OS/Arch:      linux/amd64
	 Experimental: false

Now I can use my multi-stage Dockerfile to build my Go projects. Next step is to setup my own docker registry so I can host the builds on the antsle.