Program structure

To summarize the previous section, here is a sketch of a typical cfengine configuration program showing a sensible structure. The various sections are listed in a sensible order which you would probably use in the action sequence.

An individual section-declaration in the program looks something like this:

action-type:

   class1::

       list of things to do...

   class2::

       list of things to do...

action-type is one of the following reserved words:

   groups, control, homeservers, binservers, mailserver, mountables,
   import, broadcast, resolve, defaultroute, directories, miscmounts,
   files, ignore, tidy, required, links, disable, shellcommands, 
   editfiles, processes

The order in which declarations occur is not important to cfengine from a syntactical point of view, but some of the above actions define information which you will want to refer to later. All variables, classes, groups etc. must be defined before they are used. That means that it is smart to follow the order above for the sections in the first line of the above list.

The order in which items are declared is not to be confused with the order in which they are executed. This is determined by the actionsequence, See section control. Probably you will want to coordinate the two so that they match as far as possible.

For completeness, here is a complete summary of the structure of a very general cfengine configuration program. The format is free and use of space is unrestricted, though it is always a good idea to put a space in front before and after parentheses when defining variables.

######################################################################
# 
# Example of structure
#
######################################################################

groups:
 
   group1 = ( host host ...  )
   group2 = ( host host ...  ) 
   ...

######################################################################

control: 

   class::

   site      =  ( mysite )
   domain    =  ( mydomain )
   ...

    actionsequence = 
      (
      action name
      ....
      )

   mountpattern = ( mountpoint )
   homepattern = ( wildcards matching home directories ) 

   addclasses = ( foo bar )

######################################################################

homeservers:

   class::  
           home servers

binservers:

   class::
           binary servers

mailserver:

   class::
           mail server

mountables:

   class::

           list of resources

######################################################################

import: 

   class::    include file

   class::    include file

######################################################################

broadcast:

  class::  ones   # or zeros / zeroes

defaultroute:

   class::  my-gw

######################################################################

resolve:

   any::

       list of nameservers

   ...

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