Linux service

Thanks to Guy McArthur and Carlos Hanson for the examples and much of the explanation for this tutorial.

Modifying httpd.sh

The easiest way to start Resin when Linux boots is to modify your httpd.sh and create symbolic link in /etc/rc.d/rc3.d and /etc/rc.d/rc5.d. Because the boot process does not set environment variables, you'll need to set them in the httpd.sh.

1. Copy httpd.sh to "resin-a.sh" in resin/bin and change permissions.
2. Configure JAVA_HOME, RESIN_HOME, PATH, and "-pid" in resin-a.sh.
3. Check that "resin-a.sh start" and "resin-a.sh stop" work from the command line when running as root.
4. "ln -s /usr/local/resin/bin/resin-a.sh /etc/rc.d/rc3.d/S86resin-a"
5. "ln -s /usr/local/resin/bin/resin-a.sh /etc/rc.d/rc5.d/S86resin-a"
6. "ln -s /usr/local/resin/bin/resin-a.sh /etc/rc.d/rc2.d/K14resin-a"
7. Reboot to test.

A sample resin-a.sh might look like:

#! /bin/sh
#
# ...
#
JAVA_HOME=/usr/java
export JAVA_HOME
 
RESIN_HOME=/usr/local/resin
export RESIN_HOME
 
PATH=/bin:/usr/bin:/usr/local/bin
export PATH

args="-Xms75M -Xmx100M start -pid $RESIN_HOME/resin-a.pid"
class=com.caucho.server.http.HttpServer
name=httpd
 
perl=/usr/local/bin/perl
 
exec $perl $RESIN_HOME/bin/wrapper.pl -chdir -name "$name" \
                                      -class "$class" $args $*

An advantage of this method is that you can use the same script to start and start the server interactively.

Linux booting background

At startup, Linux runs the /etc/rc.d/rc script at the current runlevel (normally 3 or 5). All the Sxx scripts in /etc/rc.d/rc3.d/S* are started in order.

for i in /etc/rc$runlevel.d/S*; do
  $i start
done

So S86resin-a will be called as "S86resin-a start" as the root user. Since the script can't assume any environment variables, it needs to set them itself.

Since Resin is an application, as opposed to a system service, it should be started late in the boot process. S86 is a decent choice. The specific order only matters if your startup depends on another service. For example, if you have a load-on-startup servlet that depends on a database, the database should be S85 or lower.

Some configurations boot up in runlevel 3 and others boot in runlevel 5. The actual boot order will then be {1,2,3} or {1,2,5}. A machine booting with runlevel 3 will have /etc/inittab with the following line:

id:3:initdefault

On server shutdown, Linux calls the scripts in /etc/rc.d/rc2.d/K* in order.

for i in /etc/rc$runlevel.d/K*; do
  $i stop
done

In this case, Resin is an application, as opposed to a system service, it should be killed early in the shutdown process.

Alternatives

An alternative to modifying the httpd.sh is to create another script that passes arguments to the original httpd.sh.

#!/bin/sh 

# script name: resin 
# 
# start/stop script for Resin 

RESIN_HOME=/usr/resin 
JAVA_HOME=/usr/java/jdk1.3 
PATH="$PATH:/usr/java/jdk1.3/bin:/usr/X11R6/bin" 
export PATH JAVA_HOME RESIN_HOME 

${RESIN_HOME}/bin/httpd.sh -Xms75M -Xmx100M -java_home ${JAVA_HOME} "$*" 

Guy McArthur writes

I find it a bit easier to edit wrapper.pl rather than creating a script that passes in environment variables. But that's just because I'll be starting/stopping resin manually using httpd.sh to try something out, so having that single point of control is good.

Carlos Hanson writes:

I originally started by editing wrapper.pl, but having a script that passes the necessary arguments to httpd.sh allows me to reinstall or upgrade Resin more easily. All I have to worry about is configuration files. This is important when dealing with developers new to Unix and maintaining a large number of production and development servers. We keep the script and the conf files in source control.