On Wed, 24 Sep 2003, Philip Hazel wrote:
> [Aside 1: Smail used multiple config files; for Exim I went for one file
> instead, partly for the performance reason, but partly because I want to
> be able to see the whole thing at once in my editor. Seems like not
> everyone feels this way. :-]
>
> [Aside 2: For absolute maximum performance in this area, I would write a
> script to build the "live" config from one or more source files,
> stripping out all the comments. But I suspect the performance gain would
> not be very much. Exim is, after all, limited by disk accesses rather
> than cpu.]
I'm sure that everyone who's interested in something like this has already
come up with their own way to do this, but here's my solution:
When I moved from smail to exim I built a program that took individual
config pieces stripped all the comments and built a config file. As a
bonus, it also runs exim -C <testfile> -bV on the new file and reports any
config errors before copying it over the old config. In addition to just
being familiar in general w/ all the files being broken up according to
their major categories, I also got the benfit of being able to have config
pieces that were easily updatable (just replace the whole file and rebuild
the configure file).
The script has some site-specific stuff hard coded, but it's easily
fixable. Essentially in my exim configd I have a directory called
subconfigure, which can contain directories named \d\d.\w+. Mine
currently contains:
10.general/ 30.routers/ 50.retry/ 70.authenticators/
20.acls/ 40.transports/ 60.rewrite/ 80.local_scan/
Each of these directories can contain files in the form \d\d.\w+. For
instance, my 30.routers contains:
00.begin 80.l_user_delivery_normal _50.l_mx
10.r_forcepaths _12.r_static_route_junk _60.l_psp
15.r_stalemail _17.r_internal_route _72.l_aliases_list
33.r_mailrtrd_router _20.r_conditionalforce _74.l_aliases_isp
40.r_standard _31.r_mailrtrd_bypass_spam _76.l_aliases_mer
70.l_aliases _39.r_smarthost _80.l_user_delivery_isp
those files prefixed by "_" will not be used to build the live configure
file. They are "turned off". This allows me to keep a general list of
configure pieces that are easily updatable but not necessarily every rule
is used on every machine. Not every file contains a single router - for
instance 60.l_psp is our virtual hosting solution and contains 10 routers.
They're just grouped by logical role.
All of these sub pieces are built in to the configure file w/ a shell
script called mkconfigure, inline below. Again, my assumption is that
anyone who wants a system like this built it for themselves, but it
would be kind of fun to flesh this script out to be more generic.
Maybe post it and some samples on a webpage. Or no one responds to this
and I shut up about it =).
This system is way overkill for some people (for instance, my home machine
uses a single configure file because I don't do that much special with
it), but it's useful in a larger system role.
--John
mkconfigure:
#!/bin/ksh
# I have found that our custom set up of exim's configure file is overly
# confusing. To help alleviate this, I have broken the file out into its
# core pieces (general, tansports, directors, routers, retry, rewrite, and
# authentication), and then each of those into logical sub-pieces (SIS,
# for instance. This program is to take all of those sub pieces and put
# them back together into the file that exim understands.
# No one should every touch the 'configure' file from now on, one should
# instead manipulate the files in the subconfigure directory and run this
# program
# jetmore 20011119
EXIMD=$1
CONFIGSUFF=$2
if [ "X$EXIMD" == "X" ] ; then
EXIMD=/local/exim
fi
if [ ! -d "$EXIMD" ] ; then
echo "$EXIMD is not a directory" >&2
exit 1
fi
ETCD=$EXIMD/etc
SUBCD=$ETCD/subconfigure$CONFIGSUFF
CONFIGF=$ETCD/configure$CONFIGSUFF
if [ ! -d $SUBCD ] ; then
echo "$SUBCD is not a directory" >&2
exit 1
fi
GREP=/bin/grep
# initialize the temporary config file in case some trash got left around
cat /dev/null > $CONFIGF.t
# print the banner to the temp config file
echo >> $CONFIGF.t
echo "#########################################################" >> $CONFIGF.t
echo "# DO NOT DIRECTLY MANIPULATE THIS FILE " >> $CONFIGF.t
echo "# " >> $CONFIGF.t
echo "# if you need to make configuration change, do so in " >> $CONFIGF.t
echo "# $SUBCD and run the mkconfigure" >> $CONFIGF.t
echo "# command. Changes made to this file will be lost " >> $CONFIGF.t
echo "# " >> $CONFIGF.t
echo "# See jetmore w/ questions " >> $CONFIGF.t
echo "#########################################################" >> $CONFIGF.t
echo >> $CONFIGF.t
# get the major categories
for CAT in $SUBCD/[0-9]*
do
# print which category we're in
echo >> $CONFIGF.t
echo "## major category $CAT" >> $CONFIGF.t
echo >> $CONFIGF.t
# get the subcategories
for SUBCAT in $CAT/[0-9]*
do
# print which sub category we're in
echo "## sub category $SUBCAT" >> $CONFIGF.t
echo >> $CONFIGF.t
# place the contents of any non-comment line into the configure file
$GREP -v "^ *#" $SUBCAT >> $CONFIGF.t
echo >> $CONFIGF.t
done
done
# check and make sure there aren't any typos in the new config file
$EXIMD/bin/exim -C $CONFIGF.t -bV > $CONFIGF.test 2>&1
if [ "$?" -eq "1" ] ; then
#/bin/rm $CONFIGF.t
echo
echo "There is a problem with the configure file. "
echo "moving paniclog to paniclog.mkfail"
echo "$CONFIGF.test has details:"
echo
echo #####################################################################
cat $CONFIGF.test
echo #####################################################################
echo
echo "$CONFIGF not changed!"
/bin/mv -f /log/exim/paniclog /log/exim/paniclog.mkfail
exit 1
fi
/bin/rm $CONFIGF.test
/bin/mv $CONFIGF.t $CONFIGF
echo "$CONFIGF updated successfully."
echo "Don't forget to HUP the mail daemon"
exit 0
