[Seaside] Monit on Ubuntu / Debian to monitor Seaside images

[Ramon Leon]

>     for an automatic installation of a service some script 
> factory will be needed but is very easy to make once we have 
> the script to start stop images. Just writing the template 
> script with customized process name port and path.

This is what daemontools makes so easy to do.  Ubuntu just stopped using
inittab so daemontools doesn't appear to install correctly, but it's easily
remedied by dropping this...

start on runlevel 2
start on runlevel 3
start on runlevel 4
start on runlevel 5
stop on runlevel 0
stop on runlevel 1
stop on runlevel 6
respawn
exec /command/svscanboot

into /etc/event.d, much better than init.d style services and automatically
monitored and restarted if they die.  My run script for a squeak image with
daemontools looks like this...

#!/bin/bash
exec squeakvm -mmap 100m -headless \
    -vm-sound-null -vm-display-null \
    /var/squeak/someApp/app.image "" port 3434

Creating a service with daemontools is merely a matter of creating a
symbolic link in the /service directory to your run scripts directory, the
service is automatically started and monitored within 5 seconds or so.

>     I've not worked yet on the balancer part but I think we 
> can use HAProxy as Ramon's blog says making it to balance 
> load using the rigth set of services.
>  
>     cheers,
> Sebastian Sastre

I wouldn't recommend that anymore, I'd use Apache now, you probably won't be
able to find a version of HAProxy, and mod_proxy can do it just as well.

Ramon Leon