# Lazy client, part II


I want to quiet, full blown PC, without fans nor a harddisk in my living
room. See my other blog about [this
subject](/2008/july/24/not_thin_not_thick_but_lazy/index.html)

Currently I'm thinking about the following setup:

 * NFS4 root
 * some sort of configuration management

I wanted to use puppet, but after seeing it use more than 30% of my main
memory -- This is on a AMD64 Ubuntu server -- I was ready to ditch it.

I've also have experience with `cfengine`, so I'm going to use that. In
conjunction with `svn`. I'm going to store all my configs + cfengine
files in one repository. The modus operandi will become:

 1. edit a file 
 1. check it into subversion
 2. periodically check out the subversion to a directory where
 cfengine will look for updates - this will probably happen every
 5 minutes
 2. let cfegine distribute the changes to other machine
 3. let the `cfagent` on the different machine figure out what
 to do.

So this blog is now becomming a post on how to configure cfengine :)

# CFegine
The shortest none trivial snippet I could think of is

    control:
	actionsequence = ( shellcommands )

    shellcommands:
	!motd::
	    "/bin/echo Danger Robinson!" define=motd

	motd::
	    "/bin/echo Ha ha after the first echo!"

Note: no spaces are allowed in `define=motd`. With this you can get
extra ordering.

From here we can do wilder stuff, like for instance getting
a copy from the `motd` file and running a post processing 
which is needed in Debian: 

    uname -snrvm > /var/run/motd
    [ -f /etc/motd.tail ] && cat /etc/motd.tail >> /var/run/motd

`/etc/motd` is a symlink pointing to `/var/run/motd`.
All commands in the `shellcommands` section should begin with a
`/`, hence the weird looking: `/usr/bin/[`.

Going about this, I'm getting to the following snippet:

    control:
	actionsequence = ( copy shellcommands )

    copy:
	/home/miekg/svn/etc/branches/elektron/motd.tail
	dest=/etc/motd.tail
	mode=644
	owner=root
	group=root
	define=motd_copied

    shellcommands:
	motd_copied::
	    "/bin/uname -snrvm > /var/run/motd"
	    "/usr/bin/[ -f /etc/motd.tail ] && /bin/cat /etc/motd.tail >> /var/run/motd"

Which will update `/etc/motd` if there is a change. 

# Subversion
I've created a subversion repository where I'm going to put these files
in. A cronjob will periodically check this out into `/etc/cfengine` so
that `cfengine` will pick up any new changes automatically. 

# Testing 
I've found that `sudo cfagent -Hnvf cfagent.conf` is a very neat way to
test out any given `cfagent.conf`, before deploying it for real.

Later on I will blog some more about the precise setup I'm going to use.