[65] in athena10
debathena-replace-conffiles idea
daemon@ATHENA.MIT.EDU (Tim Abbott)
Wed Jan 30 02:58:10 2008
Date: Wed, 30 Jan 2008 02:57:28 -0500 (EST)
From: Tim Abbott <tabbott@MIT.EDU>
To: athena10@MIT.EDU
Message-ID: <Pine.LNX.4.64L.0801292249260.23541@yaz-pistachio.mit.edu>
MIME-Version: 1.0
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Current debathena configuration packages using the
debathena-check-conffiles.mk interface are reasonably short but somewhat
ugly (pam-config is particularly ugly because it has so many changes).
Currently, debathena-ldap-config looks like:
---------------------------------------------------------------
DEB_AUTO_UPDATE_DEBIAN_CONTROL = 1
DEBATHENA_DIVERT_FILES_debathena-ldap-config += \
/etc/ldap/ldap.conf.debathena
include /usr/share/cdbs/1/rules/debhelper.mk
include /usr/share/cdbs/1/rules/debathena-divert.mk
include /usr/share/cdbs/1/rules/debathena-check-conffiles.mk
common-build-indep:: debian/ldap.conf.debathena
debian/ldap.conf.debathena: $(call debathena_check_conffiles,/etc/ldap/ldap.conf)
perl -0pe ' \
s/^#BASE.*$$/BASE\tdc=mit, dc=edu/m and \
s/^#URI.*$$/URI\tldap:\/\/ldap.mit.edu\nTLS_CACERT\t\/usr\/share\/debathena-ssl-certificates\/mitCA.pem/m or die' $< > $@
clean::
rm -f debian/ldap.conf.debathena
---------------------------------------------------------------
Packages like debathena-pam-config that change more than one configuration
file tend to have several copies of much of the above code.
The new interface I'm considering would look something like:
---------------------------------------------------------------
DEB_AUTO_UPDATE_DEBIAN_CONTROL = 1
DEBATHENA_REPLACE_CONFFILES_debathena-ldap-config += \
/etc/ldap/ldap.conf.debathena
include /usr/share/cdbs/1/rules/debhelper.mk
include /usr/share/cdbs/1/rules/debathena-replace-conffiles.mk
---------------------------------------------------------------
debathena-replace-conffiles would include debathena-divert.mk and
debathena-check-conffiles.mk, registering /etc/ldap/ldap.conf.debathena
for diversion and /etc/ldap/ldap.conf for checking. It would do the
actual modification using a script called something like
debian/deb_gen_ldap.conf.debathena, i.e.
debian/deb_gen_ldap.conf.debathena < debian/conffile-copies/etc/ldap/ldap.conf > debian/ldap.conf.debathena
where the first argument comes from the output of
$(call debathena_check_conffiles,/etc/ldap/ldap.conf) and the second
argument is the basename of /etc/ldap/ldap.conf.debathena.
It would also setup the cleaning of debian/ldap.conf.debathena.
We would include the perl code to do the modifications in its own perl
script, rather than how it is currently inlined in the rules file. This
would result in much more readable perl scripts for modifying
configuration files (embedding perl code in Makefiles is annoying because
you need to use $$ for perl variables and add \ at the end of each line,
and perl syntax highlighting doesn't work by default in normal editors
which tends to result in hard-to-read code).
Notice that this interface would not support a single package diverting
two configuration files by the same name in different directories. I
think this is unlikely to be relevant for any real configuration package.
Looking through our existing packages using the debathena-check-conffiles
system, all of them also divert the file by the corresponding name.
nsswitch-config and gconf2-config sometimes use a template file (when it
exists) for the configuration file, and so would not benefit as much from
this new interface.
My draft module is currently available in
/mit/debathena/packages/config/config-build-common/debathena-config-build-common-4.0/debathena-replace-conffiles.mk.
It's primary implementation fault is it requires the .debathena to be at
the end of the file name, but I don't consider this to be particularly
important.
-Tim Abbott
