Cloud-Config File for CoreOS with 2 GB of Swap on DigitalOcean

I recently installed Discourse on a CoreOS node at DigitalOcean. Since I chose the minimum spec that Discourse can run on, 1 GB memory, I had to enable 2 GB of swap space. This is solved by configuring CoreOS with an automatic swap service, through the standard cloud-config file. My complete cloud-config file (input this into the node’s user data) looks as follows:

#cloud-config

coreos:
  etcd2:
    # generate a new token for each unique cluster from https://discovery.etcd.io/new?size=3
    # specify the initial size of your cluster with ?size=X
    discovery: https://discovery.etcd.io/
    # multi-region and multi-cloud deployments need to use $public_ipv4
    advertise-client-urls: http://$private_ipv4:2379,http://$private_ipv4:4001
    initial-advertise-peer-urls: http://$private_ipv4:2380
    # listen on both the official ports and the legacy ports
    # legacy ports can be omitted if your application doesn't depend on them
    listen-client-urls: http://0.0.0.0:2379,http://0.0.0.0:4001
    listen-peer-urls: http://$private_ipv4:2380
  units:
    - name: etcd2.service
      command: start
    - name: fleet.service
      command: start
    - name: swap.service
      command: start
      content: |
        [Unit]
        Description=Turn on swap

        [Service]
        Type=oneshot
        Environment="SWAPFILE=/2GiB.swap"
        RemainAfterExit=true
        ExecStartPre=/bin/bash -c "\
          fallocate -l 2G $SWAPFILE && \
          chmod 600 $SWAPFILE && \
          chattr +C $SWAPFILE && \
          mkswap $SWAPFILE && \
          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=local.target