Making your package work
with systemd
Michael Stapelberg <stapelberg@debian.
org>
DebConf 2013
Topics
● How systemd works (for pkg maintainers)
● Example service file
● tmpfiles.d(5), dh-systemd
● More advanced examples
● Questions
Non-topics
● systemd sucks, let’s use $initsys instead
● When will Debian switch the default?
● Essentially, anything that ever came up on
debian-devel ;-)
How systemd works
● Service files correspond to init scripts:
/etc/init.d/apache2
→ /lib/systemd/system/apache2.service
● systemctl does what service(8) did:
service apache2 start
→ systemctl start apache2.service
How systemd works (2)
● Targets correspond to runlevels:
basic.target, multi-user.target,
graphical.target, …
(see systemd.special(7))
● symlinks still enable a service:
update-rc.d apache2 defaults
→ systemctl enable apache2.service
Example service file: vnstat.service
[Unit]
Description=Network traffic monitor
[Service]
User=vnstat
ExecStart=/usr/sbin/vnstatd -n
ExecReload=/bin/kill -HUP $MAINPID
[Install]
WantedBy=multi-user.target
tmpfiles.d(5)
● useful e.g. for runtime directories:
$ cat /usr/lib/tmpfiles.d/lighttpd.conf
d /run/lighttpd 0750 www-data www-data -
● more powerful:
○ files, directories, pipes, symlinks, …
○ automatic cleanup
Service file location
● service files often shipped by upstream
● if not, use debian/pkg.{service,tmpfile}
● dh_installinit installs these files
● send service files upstream!
Getting your service enabled
● Build-Dep: dh-systemd, dh --with=systemd
● maintscripts will contain appropriate code
● deb-systemd-helper instead of systemctl
● (avoids Depends: systemd)
Testing your package
● Install systemd, boot with init=/bin/systemd
● Check your service starts properly on boot
● Check reload, stop, start, restart
Advanced examples: more features
[Unit]
Description=Debian Code Search: web frontend
[Service]
User=dcs
Group=dcs
ExecStart=/usr/bin/dcs-web \
-template_pattern=/usr/share/dcs/templates/*
StandardOutput=null
StandardError=journal
RestartSec=1
Restart=on-failure
[Install]
WantedBy=multi-user.target
Advanced examples: dbus-activated
[Unit]
Description=Manage, Install and
Generate Color Profiles
[Service]
Type=dbus
BusName=org.freedesktop.ColorManager
ExecStart=/usr/lib/colord/colord
User=colord
PrivateTmp=yes
Advanced examples: dh-systemd
# Only cleanup on purge,
# don’t enable service by default.
override_dh_systemd_enable:
dh_systemd_enable \
--no-enable
override_dh_systemd_start:
dh_systemd_start \
--restart-after-upgrade
Need help?
● Check https://wiki.debian.org/Systemd/Packaging
● Stop by at #debian-systemd any time
● Ask [email protected]
● We mean it. Please ask.
Thanks! Any questions?
● Thanks for your attention
● Add systemd support today ♥
● Questions?
