git-annex/doc/todo/server-level_daemon__63__.mdwn
2015-05-01 13:57:23 -04:00

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coming from [[bugs/weird_entry_in_process_list]] - are there plans to make an init.d / systemd .service file for git-annex?
my use case is that i have dedicated machines that will sync a common directory. they will run only one assistant - would patches to make a `git-annex` user, and the associated startup scripts, in the debian package be welcome? --[[anarcat]]
Here's a sample startup script:
<pre>
#!/bin/sh
### BEGIN INIT INFO
# Provides: gitannex
# Required-Start: $local_fs $network $remote_fs $syslog
# Required-Stop: $local_fs $network $remote_fs $syslog
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: start the git-annex assistant
# Description: start the git-annex assistant in the given directory
### END INIT INFO
# Author: Antoine Beaupré <anarcat@koumbit.org>
# Do NOT "set -e"
# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="gitannex"
NAME=gitannex
USER=$NAME
DAEMON=git-annex
DAEMON_ARGS="assistant"
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME
ANNEX=auto
# Read configuration variable file if it is present
[ -r /etc/default/$NAME ] && . /etc/default/$NAME
# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0
# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh
# Define LSB log_* functions.
# Depend on lsb-base (>= 3.2-14) to ensure that this file is present
# and status_of_proc is working.
. /lib/lsb/init-functions
if [ "$ANNEX" = "auto" ]; then
DAEMON_ARGS="$DAEMON_ARGS --autostart"
else
cd $ANNEX
PIDFILE="$ANNEX/.git/annex/daemon.pid"
EXTRA_OPTS="--chdir $ANNEX"
fi
#
# Function that starts the daemon/service
#
do_start()
{
# Return
# 0 if daemon has been started
# 1 if daemon was already running
# 2 if daemon could not be started
start-stop-daemon --start --quiet --user $USER --pidfile $PIDFILE --exec $DAEMON --test > /dev/null \
|| return 1
start-stop-daemon --start --quiet --user $USER --chuid $USER $EXTRA_OPTS --pidfile $PIDFILE --exec $DAEMON -- \
$DAEMON_ARGS \
|| return 2
# The above code will not work for interpreted scripts, use the next
# six lines below instead (Ref: #643337, start-stop-daemon(8) )
#start-stop-daemon --start --quiet --pidfile $PIDFILE --startas $DAEMON \
# --name $NAME --test > /dev/null \
# || return 1
#start-stop-daemon --start --quiet --pidfile $PIDFILE --startas $DAEMON \
# --name $NAME -- $DAEMON_ARGS \
# || return 2
# Add code here, if necessary, that waits for the process to be ready
# to handle requests from services started subsequently which depend
# on this one. As a last resort, sleep for some time.
}
#
# Function that stops the daemon/service
#
do_stop()
{
# Return
# 0 if daemon has been stopped
# 1 if daemon was already stopped
# 2 if daemon could not be stopped
# other if a failure occurred
su $USER -c "$DAEMON $DAEMON_ARGS --stop" && return 0
# Wait for children to finish too if this is a daemon that forks
# and if the daemon is only ever run from this initscript.
# If the above conditions are not satisfied then add some other code
# that waits for the process to drop all resources that could be
# needed by services started subsequently. A last resort is to
# sleep for some time.
start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --user $USER --exec $DAEMON
[ "$?" = 2 ] && return 2
# Many daemons don't delete their pidfiles when they exit.
rm -f $PIDFILE
return "$RETVAL"
}
#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
#
# If the daemon can reload its configuration without
# restarting (for example, when it is sent a SIGHUP),
# then implement that here.
#
start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME
return 0
}
case "$1" in
start)
[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
do_start
case "$?" in
0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
stop)
[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
do_stop
case "$?" in
0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
esac
;;
status)
status_of_proc -p "$PIDFILE" "$DAEMON" "$NAME" && exit 0 || exit $?
;;
#reload|force-reload)
#
# If do_reload() is not implemented then leave this commented out
# and leave 'force-reload' as an alias for 'restart'.
#
#log_daemon_msg "Reloading $DESC" "$NAME"
#do_reload
#log_end_msg $?
#;;
restart|force-reload)
#
# If the "reload" option is implemented then remove the
# 'force-reload' alias
#
log_daemon_msg "Restarting $DESC" "$NAME"
do_stop
case "$?" in
0|1)
do_start
case "$?" in
0) log_end_msg 0 ;;
1) log_end_msg 1 ;; # Old process is still running
*) log_end_msg 1 ;; # Failed to start
esac
;;
*)
# Failed to stop
log_end_msg 1
;;
esac
;;
*)
#echo "Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}" >&2
echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
exit 3
;;
esac
:
</pre>
Now this is not without problems:
1. it assumes a gitannex user is created outside of the script
2. it assumes a gitannex repository is created outside of the script and specified in the `/etc/default/gitannex` file (or added to the autostart file)
3. it is Debian-specific (a proper init script would be POSIX only and/or a `.service` file)
Maybe using [metainit](https://wiki.debian.org/MetaInit) would be a good idea here? --[[anarcat]]
> This strikes me as a bad idea if the system has regular desktop etc
> users; the assistant can already start itself when they login and
> a separate user has the same problems the separate mpd user seems to;
> of separating the user from the files that effcetively belong to them.
>
> It's fine if you're doing something more specialized, but that seems
> like an unusual case and not one that git-annex should cater to.
>
> Anyway, it's about 5 lines to write a systemd service file. I've added
> `git annex assistant --autostop` that such a service can use if desired.
>
> Since I don't want to include that in git-annex and be stuck supporting
> it, and it should be easy for users to add if they need it, I think I'm
> going to call this [[done]]. --[[Joey]]