ruby dev machine config example for mac/docker-machine/coreos

Assuming:
a) you have exported /users via /etc/exports and turned nfsd on
b) you have VirtualBox as a vm runner

Then, you need a config-drive yaml like the following to configure your dev vm

#cloud-config
---
hostname: dev

ssh_authorized_keys:
 - ssh-rsa <some key>

write_files:
 - path: "/etc/docker/certs.d/registry.ag.local:5000/ca.crt"
 permissions: "0644"
 owner: "root"
 content: |
 -----BEGIN CERTIFICATE-----
 CA cert of a local registry goes here
 -----END CERTIFICATE-----

coreos:
 update:
 group: stable
 reboot-strategy: best-effort
 units:
 - name: update-engine.service
 command: start
 enable: true

 - name: docker.service
 command: start
 enable: true
 drop-ins:
 - name: 10-wait-docker.conf
 content: |
 [Unit]
 After=Users.mount
 Requires=Users.mount

 - name: swapon.service
 command: start
 content: |
 [Unit]
 Description=Turn on swap
 [Service]
 Type=oneshot
 Environment="SWAPFILE=/4GiB.swap"
 RemainAfterExit=true
 ExecStartPre=/usr/bin/touch ${SWAPFILE}
 ExecStartPre=/usr/bin/chattr +C ${SWAPFILE}
 ExecStartPre=/usr/bin/fallocate -l 4096m ${SWAPFILE}
 ExecStartPre=/usr/bin/chmod 600 ${SWAPFILE}
 ExecStartPre=/usr/sbin/mkswap ${SWAPFILE}
 ExecStartPre=/usr/sbin/losetup -f ${SWAPFILE}
 ExecStart=/usr/bin/sh -c "/sbin/swapon $(/usr/sbin/losetup -j ${SWAPFILE} | /usr/bin/cut -d : -f 1)"
 ExecStop=/usr/bin/sh -c "/sbin/swapoff $(/usr/sbin/losetup -j ${SWAPFILE} | /usr/bin/cut -d : -f 1)"
 ExecStopPost=/usr/bin/sh -c "/usr/sbin/losetup -d $(/usr/sbin/losetup -j ${SWAPFILE} | /usr/bin/cut -d : -f 1)"
 [Install]
 WantedBy=multi-user.target

 - name: Users.mount
 command: start
 content: |
 [Unit]
 After=syslog.target network.target
 Before=docker.service
 [Mount]
 What=192.168.99.1:/Users
 Where=/Users
 Type=nfs
 Options=async,noacl,fsc
 TimeoutSec=300
 [Install]
 RequiredBy=docker.service
 WantedBy=docker.service

Highlights:

• It handles the local docker registry with the corresponding CA cert
• It handles NFS mount of a host directory tree containing the source
• It makes a swapfile just in case…