Re: Editfiles Considered Harmful (was: Re: Complex Editfiles Examples)

[Jamie Wilkinson]

This one time, at band camp, Eric Sorenson wrote:
>It really terrifies me when I see stuff like this.

:-)

>Not that your editfiles won't work (necessarily); it's just scary to think that
>as a general practice, people let tools generate syntax which have no idea
>themselves whether the syntax is valid.  

It's true, I don't like it at all.

>snip good arguments

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 that editfiles is a hack, and not well suited for the
task of convergence of configuration files: for really simple things it
is very good, but configuration files are rarely simple.

My goal is to have a section that takes care of the details of doing
edits, where instead of describing how to make the changes as I
currently am, I only have to specify the key and value for some
configuration and have cfengine take care of it.

My editfiles structures came about because I encountered several
situations, like the ones you described, where editfiles wasn't
convergent, and so now I have 8 or so lines for each key/value pair
to ensure edit safety where two should suffice.

I'm sure I mentioned this about 6 months ago, a library I was working on
to take care of the edits, knowing about structure and so on, but
unfortunately development on that has stagnated.

-- 
jaq@spacepants.org                           http://spacepants.org/jaq.gpg