Merge branch 'docker-snapshots'

#!/bin/sh

set -eu

# Cleanup of snapshots, added as trap so it's always executed even in case of a

# failure or ctrl+c.

cleanup () {

    btrfs subvolume delete "$snapshot"

}

usage () {

    echo "Usage: $(basename "$0") DESTINATION" >&2

    exit 1

}

get_mountpoint () {

    df --output=target "$1" | tail +2

}

get_snapshot () {

    name="$1"

    mountpoint="$(docker volume inspect --format '{{ .Mountpoint }}' "$name" )"

    snapshot="$(dirname "$mountpoint")/snapshot)"

    echo "$snapshot"

}

if [ "$#" -ne 1 ]

then

    usage

elif [ ! -d "$1" ]

then

    echo "Destinaton $1 not found or is not a directory." >&2

    exit 1

elif [ "$(id -u)" -ne 0 ]

then

    echo "This program must run as root." >&2

    exit 1

elif ! command -v btrfs >/dev/null

then

    echo 'btrfs-progs must be installed.' >&2

    exit 1

elif ! docker info --format '{{ .ServerVersion }}' >/dev/null

then

    echo 'Docker must be installed and running.' >&2

    exit 1

elif ! df --type=btrfs /var/lib/docker/volumes >/dev/null

then

    echo "Docker volumes are not on a btrfs filesystem." >&2

    exit 1

elif ! df --type=btrfs "$1" >/dev/null

then

    echo "Destination $1 is not on a btrfs filesystem." >&2

    exit 1

elif [ "$(df --output=target /var/lib/docker/volumes)" != "$(df --output=target "$1")" ]

then

    echo "The destination $1 is not on the same btrfs volume as the Docker volumes." >&2

    exit 1

elif [ -z "$(docker volume ls --filter label=snapshot=true --format '{{ .Name }}')" ]

then

    echo "No Docker volumes marked for backup, exiting." >&2

    exit 1

fi

dest="$1"

root_volume="$(get_mountpoint /var/lib/docker/volumes)"

snapshot="$(mktemp --dry-run "--tmpdir=$root_volume")"

trap 'cleanup' INT QUIT EXIT TERM

btrfs subvolume snapshot "$root_volume" "$snapshot"

for name in $(docker volume ls --filter label=snapshot=true --format '{{ .Name }}')

do

    echo "Backing up $name."

    mountpoint="$(docker volume inspect --format '{{ .Mountpoint }}' "$name")"

    src="$snapshot/${mountpoint#$root_volume/}"

    # shellcheck disable=SC2115

    [ ! -e "$dest/$name" ] || rm -rf "$dest/$name"

    cp --archive --force --reflink=always "$src" "$dest/$name"

done

# vim: filetype=systemd

[Unit]

Description=Docker volume backup (dvb)

ConditionACPower=true

After=local-fs.target

[Service]

Type=exec

ExecStart=dvb /var/backups/docker-volumes

# vim: filetype=systemd

[Unit]

Description=Docker volume backup (dvb)

[Timer]

OnCalendar=weekly

RandomizedDelaySec=21600

[Install]

WantedBy=multi-user.target

      {{ (ansible_facts.mounts|selectattr("device", "equalto", device)|first)["mount"] }}

    # yamllint enable rule:line-length

  tags: [scrub]

  notify:

    - Systemd daemon reload

- name: Enable btrfs scrub timers

  ansible.builtin.systemd:

    mode: 0o0644

    src: btrfs_check.{{ item }}.j2

  vars: *vars

  notify:

    - Systemd daemon reload

- name: Enable the btrfs check timers

  ansible.builtin.systemd:

    mode: 0o0644

  notify:

    - Systemd daemon reload

    - Restart Docker

- name: Allow access from the toolbox container

  ansible.builtin.copy:

    direction: in

    interface: docker0

    rule: allow

- name: Create the Docker volume backup destination directory

  ansible.builtin.file:

    group: backup

    mode: 0o0750

    owner: root

    path: /var/backups/docker-volumes

    state: directory

- name: Copy the Docker volume backup script

  ansible.builtin.copy:

    dest: /usr/local/bin/

    mode: preserve

    src: dvb

- name: Copy the Docker volume backup service and timer

  loop:

    - service

    - timer

  ansible.builtin.copy:

    dest: /etc/systemd/system/dvb.{{ item }}

    mode: 0o0644

    src: dvb.{{ item }}

  notify:

    - Systemd daemon reload

- name: Enable the Docker volume backup timer

  ansible.builtin.systemd:

    enabled: true

    name: dvb.timer

  notify:

    - Systemd daemon reload