C1 image created with docker base image using 
`armv7l 4.10.8 docker #1` bootscript.

Machines:

    $ ssh -i ~/keys/id_ed25519_golang1 root@$C1_SERVER_IP
    (key: http://go/go-builders-ssh)

Machine setup:
	# local:
	$ scp env/linux-arm/scaleway/* root@$C1_SERVER_IP:~/scaleway

	$ GOARCH=arm GOOS=linux go install golang.org/x/build/cmd/rundockerbuildlet && \
	 scp ~/bin/linux_arm/rundockerbuildlet root@$C1_SERVER_IP:/usr/local/bin
	$ GOARCH=arm GOOS=linux go install golang.org/x/build/cmd/buildlet/stage0 && \
	 scp ~/bin/linux_arm/stage0 root@$C1_SERVER_IP:~/scaleway
	# NOTE: commit SHA of rundockerbuildlet/stage0 on instance snapshot (06/19/17)
	# golang.org/x/build is 282d813.

	$ scp rundockerbuildlet.service root@$C1_SERVER_IP:/etc/systemd/user/

	# c1 server:

	$ echo "<BUILDER KEY>" > /etc/gobuild.key > /root/.gobuildkey

	$ apt-get remove --purge unattended-upgrades

	$ systemctl enable /etc/systemd/user/rundockerbuildlet.service
	$ systemctl start rundockerbuildlet.service