Re: DHCP client with minimal functionality and size

[Thor Lancelot Simon <tls%rek.tjls.com@localhost>]

On Fri, Apr 11, 2008 at 07:16:22AM +0100, Roy Marples wrote:
> On Thursday 10 April 2008 23:46:21 David Brownlee wrote:
> >     As other people have mentioned its probably best to have
> >     the default behaviour of dhcpcd to be changing no more than
> >     dhclient, to avoid annoying people.
> 
> I can understand that.
> I'll ask the maintainers of dhcpcd in some Linux distros as that change would 
> affect them as it's changing a long standing default behaviour.
> 
> However, I do think it's fair that if you request an option that dhcpcd knows 
> about, such as NTP servers, then it will configure them for you.

...and we arrive at the reason why ISC dhclient has scripts for manipulating
the system.  Some users are naive about their system and network
configurations and just want the DHCP client to "do magic" -- they don't know
about existing configuration files and don't care what it does to them.

Other users, on the other hand, have quite a bit of local configuration
state and under no circumstances want a network client program blindly
overwriting it -- but parsing the configuration file for daemon _X_ in a
small C program like a dhcp client should be is not practical.

For all the flaws of ISC dhclient the use of scripts for managing
configuration files after state changes, and the set of variables it
provides to them, are very well thought out.  Done properly -- dhclient
does not do it properly! -- it should make a DHCP client smaller, not
larger, since all the work of writing ntp.conf etc. can be deferred to
the shell.

Thor