Re: [gentoo-user] Writing Gentoo initscript question

[Joost Roeleveld]

On Sunday 06 March 2011 11:25:47 Jake Moe wrote:
> On 03/06/11 09:31, Florian Philipp wrote:
> > Am 05.03.2011 23:47, schrieb Jake Moe:
> >> I'm currently trying to write a simple initscript to run
> >> minecraft-server on one of my boxes.  I've looked at the ebuild
> >> provided
> >> via java-overlay, but it turns out it uses baselayout 2, and I'm not
> >> ready to go down that upgrade path on this particular box just yet.
> >>
> >> So far, I've managed to get a simple start() function written, which
> >> kinda-sorta "works"; it will start the server, but there are two
> >> problems:
> >>
> >> 1) The "server" was written to stay interactive on a console, so you
> >> can
> >> manage it from there.  As such, the process never exits, so the
> >> initscript gets stuck on "starting"
> >> 2) There is nowhere in the server config file to specify where it
> >> writes
> >> it's data files.  So when I run this from my initscript, it seems to
> >> default to the root directory, and I can't figure out how to tell it
> >> to
> >> use something else as a working directory.
> >>
> >> So far, I've got this:
> >>
> >> depend() {
> >>
> >>   need bootmisc localmount net
> >>
> >> }
> >>
> >> start() {
> >>
> >>   einfo "Starting Minecraft Server"
> >>   cd /usr/local/games/minecraft-server
> >>   start-stop-daemon --start --make-pidfile --pidfile
> >>
> >> /var/run/minecraft-server.pid \
> >>
> >>                     --exec /usr/bin/java --
> >>                     -Xmx1024M -Xms1024M -jar
> >>
> >> /usr/local/games/minecraft-server/minecraft_server.jar nogui
> >>
> >>   eend $?
> >>
> >> }
> >>
> >> Do any of the experts here know a way out of my dilemma?
> >>
> >> Jake Moe
> >
> > You already know start-stop-daemon, good. Parameter --background will
> > force the program to detach. That solves your first problem.
> >
> > --chdir should solve your second problem. You should also consider
> > --user and --group to drop root privileges. It also sets $HOME in case
> > the server does not write to the working directory but the home
> > directory.
> >
> > Hope this helps,
> > Florian Philipp
>
> I've tried "--background", but then it just fails.  Adding "--verbose"
> as well gives the following:
>
> jmoe@aus8617 /etc/init.d $ sudo /etc/init.d/minecraft-server start
>  * Starting Minecraft Server
> Starting /usr/bin/java...
> Detaching to start /usr/bin/java...done.   [ !! ]
>
> Not the most helpful of messages.
>
> For the second, of what is "--chdir" an argument?  If I read the man
> page for start-stop-daemon, it had "--chroot" and "--chuid", but no
> "--chdir".  I assume that "--chuid" can be used for changing the
> user:group of the resulting process, but did you mean chroot instead of
> chdir, or does that go with another command?
>
> Also, when I say "the root directory", I don't mean root's home
> directory (/root), I mean the root (/) directory.  So I wind up with
> config files in the root of my filesystem.  Not good.
>
> Jake Moe

Not sure if it's the "recommended" way, but how about using "nohup"?
Eg:
start-stop-daemon --start --make-pidfile --pidfile
/var/run/minecraft-server.pid \
                    --exec nohup /usr/bin/java -- -Xmx1024M -Xms1024M -jar

Might be that it fails because it looses the stdout/stderr?

--
Joost