Re: convergent principle and editfile issue

[Brendan Strejcek]

How about this? Maybe overkill. This particular code is untested, but
I've used the same idea before.

control:

    hosts_equiv_netgroup = ( examplenetgroup )

editfiles:

    { /etc/hosts.equiv
        # Make sure we have some lines to edit
        BeginGroupIfNoLineMatching "^\+@${hosts_equiv_netgroup}$"
            Append "+@${hosts_equiv_netgroup}"
        EndGroup
        BeginGroupIfNoLineMatching "^${host}$"
            Append "${host}"
        EndGroup

        # And make sure the lines are correct
        ResetSearch "1"
        BeginGroupIfNoMatch "^\+@${hosts_equiv_netgroup}$"
            ReplaceLineWith "+@${hosts_equiv_netgroup}"
        EndGroup
        IncrementPointer "1"
        BeginGroupIfNoMatch "^${host}$"
            ReplaceLineWith "${host}"
        EndGroup
        DeleteLinesAfterThisMatching "^.*$"
    }

Zeev Fisher wrote:

> Hi,
> 
> I would like to discuss again the concept of  convergent  and editfiles.
> 
> From earlier discussion:
> 
> "The real reason for me using editfiles over copy for managing
> configuration is that sometimes the values being set differ per machine,
> which makes a single file less useful.  I certainly use copy for every
> file that I want identical across all machines, but these files are
> rarely configuration files.
> I also like to make the minimum amount of change to any configuration
> file, and I want any automatic edits to respect formatting changes that
> a human makes."
> 
> I totally agree with this and i can't understand how such great software 
> like cfengine which is based on the principle of convergent , doesn't have 
> editfiles ability to check if certain file match certain structure ( which 
> is dynamic according to
> the machine it runs on but the template is fixed)
> 
> For example , i'm trying to find a way which will make sure that only the 
> following 2 lines will appear in my hosts.equiv file :
> 
> +@examplenetgroup
> examplehost
> 
> The netgroup name is constant but the hostname is the hostname of the 
> machine itself so i can't use copy.
> 
> With all current editfiles feature , except of creating from scratch 
> every time the file with emptyentirefileplease and inserts , i can't 
> make sure that if someone added there host , it will be removed next 
> time cfengine run.
> 
> I will be happy to hear how to do this if it's possible.
> 
> 
> Thanks,
> Zeev