Re: Editfiles hack

[Tim Nelson]

On Sat, 27 Mar 2004, Russell Adams wrote:

> I've started using the following for most of my config files. I kind
> of felt it was a dirty hack, so I thought I'd ask if anyone else was
> doing the same or had suggestions.
>
> I'll use an editfiles command like the one below, basically it looks
> for a revision number as the first line of the file. If it doesn't
> match, then the entire file contents is replaced.

        Hmm.  I'd tend to do something like:

BeginGroupIfNoLineMatching "# interfaces v1.02"
        DefineInGroup "replaceinterfaces"
EndGroup

        ...and then in the copy section, just copy it from the central
server.

>
> { /etc/network/interfaces
>
> AutoCreate
>
> BeginGroupIfNoLineMatching "# interfaces v1.02"
>   EmptyEntireFilePlease
>   Append "# interfaces v1.02"
>   Append ""
>   Append "auto lo"
>   Append "iface lo inet loopback"
>   Append ""
>   Append "auto eth0"
>   Append "iface eth0 inet static"
>   Append "        address 192.168.1.170"
>   Append "        netmask 255.255.255.0"
>   Append "        network 192.168.1.0"
>   Append "        broadcast 192.168.1.255"
>   Append "        gateway 192.168.1.254"
>   Append ""
> EndGroup
> }
>
> Part of this was caused by my recent frustration trying to replace
> individual lines in the above config file in a reliable manner. (ie:
> replace address, but not all addresses...)

        Sounds like you need a ReplaceIfNoLineMatching.  I munge all my
cfengine configs with Perl on the server.  So I'd just do:

        <? ReplaceIfNoLineMatching('^\s+address .*$', "\taddress 
192.168.1.170") ?>

        ..and Perl would munge it for me into something like:

        (parameter 1 is $searchterm, parameter 2 is $text)
----------------------------
        ResetSearch "1"
        LocateLineMatching "$searchterm"
        BeginGroupIfNoLineMatching "$text"
                InsertLine "$text"
        EndGroup
        CatchAbort
----------------------------

        I actually go through about three function calls to achieve this
output, since some of the code is the same as eg. InsertAfterIfNoSuchLine,
and I allow for multiple lines to be inserted, instead of just $text

        While we're on the subject of editfiles, Mark, do you have time
yet to continue our discussion?  (Yeah, I ask these things just to annoy
you :o) ).

        Thanks all,

--
Tim Nelson
Systems Administrator
Sunet Internet
Tel: +61 3 5241 1155
Fax: +61 3 5241 6187
Web: http://www.sunet.com.au/
Email: sysadmin@sunet.com.au