SystemD
=======
Basics::

    systemctl status foo  # same as foo.service
    systemctl status foo.mount

    # what's wrong?
    systemctl --failed

    # what's slow?
    systemd-analyze blame

    systemctl list-dependencies foo.service

Compose project that needs host mount starting on boot::

    cat <<'EOF' > /etc/systemd/system/foo.service
    [Unit]
    Description=foo
    Requires=docker.service
    After=network.target docker.service foo.mount

    [Service]
    WorkingDirectory=/srv/foo

    # ExecStartPre=/usr/local/bin/docker-compose pull
    ExecStart=/usr/local/bin/docker-compose up
    ExecStop=/usr/local/bin/docker-compose down --remove-orphans

    [Install]
    WantedBy=multi-user.target
    EOF

    systemctl daemon-reload
    systemctl enable foo
    systemctl start foo


Mounts::

    vi /etc/fstab
    systemctl restart remote-fs.target


Simple service running as unprivileged user `foo` that depends on another
service and network::

    cat <<'EOF' > /etc/systemd/system/foo.service
    [Unit]
    Description=foo
    Requires=another.service
    After=network.target another.service

    [Service]
    Type=simple
    User=foo
    Group=foo
    WorkingDirectory=/srv/foo
    ExecStart=/usr/local/bin/docker-compose up
    ExecStop=/usr/local/bin/docker-compose down --remove-orphans

    [Install]
    WantedBy=multi-user.target
    EOF

    systemctl daemon-reload
    systemctl enable foo
    systemctl start foo

Links:

- https://www.freedesktop.org/software/systemd/man/systemd.mount.html


Rants
-----
Where's the 90%-use-case tutorial? Why are `User=` and `Group=` defined in
`systemd.exec <https://www.freedesktop.org/software/systemd/man/systemd.exec.html#>`_
when I want to define a
`systemd.service <https://www.freedesktop.org/software/systemd/man/systemd.service.html#>`_
in a
`systemd.unit <https://www.freedesktop.org/software/systemd/man/systemd.unit.html>`_
?