CFEngine And OpenWrt

With a recent patch to include CFEngine in Openwrt, we now have the capability to use CFEngine to manage large systems of openwrt based servers, access points, Dockstars, whatever! Awesome!

Installing CFEngine on Openwrt

The CFEngine patch by Christoph König is not yet integrated into Openwrt Upstream as of this writing. This means compiling it yourself for the platform you need using the Openwrt SDK. If you feel trusting you can download my package built for the Dockstar: http://download.xkyle.com/ipkg/cfengine_2.2.10-1_kirkwood.ipk

Defining OpenWRT Systems (class) in CFEngine

In my update.conf and cfagent.conf, I define a openwrt class first, then I can use that distinction to define other actions later on. Specifically I define my working directory as /etc/cfengine to make sure files go where they are expected:

classes:
  openwrt = ( FileExists(/etc/openwrt_release) )

control:
  actionsequence  = ( copy )
  domain          = ( YourCompany.com )
  policyhost      = ( CFengine.YourCompany.com  )
  sysadm          = ( ITguy@YourCompany.com )

  # This is with an ubuntu cfengine master server
  master_cfinput  = ( /var/lib/cfengine2/masterfiles/inputs )
  master_cffiles  = ( /var/lib/cfengine2/masterfiles/files )

  # The openwrt cfengine package likes things to be in /etc/cfengine
  openwrt::
  repository      = ( /etc/cfengine/outputs )
  workdir         = ( /etc/cfengine/ )

Using Opkg to Manage Packages

classes:
	openwrt::
	has_opkg_updates = ( FileExists(/var/opkg-lists/packages) )

control:
    openwrt::
        DefaultPkgMgr      = ( dpkg )
        DPKGInstallCommand = ( "/bin/opkg install %s" )
        DPKGRemoveCommand  = ( "/bin/opkg remove %s" )

packages:
	openwrt::
		vim-full action=install	

shellcommands:
	!has_opkg_updates::
		"/bin/opkg update"

This is not 100% ideal. Depending on your action sequence, you may not get the updated package list before the packages section. Eh, it can wait till next time. Or, this is a wiki, if you have a better solution by all means press the edit button :)

Also, since CFEngine was not build with opkg in mind, comparing versions and such don't work. In fact, it can't really even know if something is installed or not, so it just opkg installs everything on your list. Luckily opkg is super fast, so it is not much of a waste.

TODO

Write a apt-cache for openwrt to fake out cfengine? Patch cfengine to be opkg aware?