cloud-config for provisioning MariaDB on CoreOS

cloud-config.yaml

#cloud-config
coreos:
  etcd:
    addr: $private_ipv4:4001
    peer-addr: $private_ipv4:7001
    discovery: https://discovery.etcd.io/<token>
  fleet:
    public-ip: $private_ipv4
  units:
    - name: format-ephemeral.service
      command: start
      content: |
        [Unit]
        Description=Formats the ephemeral drive
        [Service]
        Type=oneshot
        RemainAfterExit=yes
        ExecStart=/usr/sbin/wipefs -f /dev/xvdb
        ExecStart=/usr/sbin/mkfs.btrfs -f /dev/xvdb
    - name: mnt.mount
      command: start
      content: |
        [Unit]
        Description=Mount ephemeral to /mnt
        Requires=format-ephemeral.service
        After=format-ephemeral.service
        Before=subvolume-ephemeral.service
        [Mount]
        What=/dev/xvdb
        Where=/mnt
        Type=btrfs
    - name: subvolume-ephemeral.service
      command: start
      content: |
        [Unit]
        Description=Subvolumes the ephemeral drive
        Requires=mnt.mount
        After=mnt.mount
        Before=var-lib-docker.mount
        [Service]
        Type=oneshot
        RemainAfterExit=yes
        ExecStart=/usr/sbin/btrfs subvolume create /mnt/mysql
    - name: var-lib-mysql.mount
      command: start
      content: |
        [Unit]
        Description=Mount ephemeral to /var/lib/mysql
        Requires=subvolume-ephemeral.service
        After=subvolume-ephemeral.service
        Before=init-mariadb.service
        [Mount]
        What=/dev/xvdb
        Where=/var/lib/mysql
        Type=btrfs
        Options=subvol=mysql
    - name: init-mariadb.service
      command: start
      content: |
        [Unit]
        Description=Initializes MariaDB
        Requires=docker.service
        After=docker.service
        [Service]
        Type=oneshot
        RemainAfterExit=yes
        ExecStart=/usr/bin/docker pull psoutham/mariadb
        ExecStart=/usr/bin/docker run --rm -it --name mysql -v /var/lib/mysql:/var/lib/mysql psoutham/mariadb mysql_install_db
        ExecStart=/usr/bin/docker run --rm -it -v /var/lib/mysql:/var/lib/mysql --name mysql psoutham/mariadb /bin/sh -c "(mysqld_safe&) && mysqladmin --silent --wait=30 ping || exit 1 && mysql -e 'GRANT ALL PRIVILEGES ON *.* TO \"root\"@\"%\";'"
    - name: mariadb.service
      command: start
      content: |
        [Unit]
        Description=MariaDB
        Requires=init-mariadb.service docker.service
        After=init-mariadb.service docker.service
        [Service]
        TimeoutStartSec=0
        ExecStartPre=-/usr/bin/docker kill mysql
        ExecStartPre=-/usr/bin/docker rm mysql
        ExecStartPre=/bin/sh -c "echo never > /sys/kernel/mm/transparent_hugepage/enabled"
        ExecStartPre=/bin/sh -c "echo never > /sys/kernel/mm/transparent_hugepage/defrag"
        ExecStartPre=/usr/bin/docker pull psoutham/mariadb
        ExecStart=/usr/bin/docker run --rm -v /var/lib/mysql:/var/lib/mysql --name mysql -p 3306:3306 psoutham/mariadb
        ExecStop=-/usr/bin/docker run --link=mysql:db --rm -it --name mysql_client psoutham/mariadb /bin/sh -c 'mysqladmin -u root -h $DB_PORT_3306_TCP_ADDR -P $DB_PORT_3306_TCP_PORT shutdown && sleep 6'
        ExecStop=-/usr/bin/docker stop mysql
    - name: etcd.service
      command: start
    - name: fleet.service
      command: start

This will nuke your data upon reboot.

On DigitalOcean:

Failed Units: 2
format-ephemeral.service
init-mariadb.service