What is policy about auto-editing config files on port install / deinstall?

[Miroslav Lachman]

olli hauer wrote:
> On 2013-01-04 09:51, Scot Hetzel wrote:
>> On Fri, Jan 4, 2013 at 2:12 AM, Scot Hetzel<swhetzel at gmail.com>  wrote:
>>>>
>>>> Why am I forced to manualy re-enable all 3rd party modules on each upgrade?
>>>>
>>>> Modules should not disable something that is explicitly enabled by user /
>>>> system administrator.
>>>>
>>>>
>>> I found the cause of your issue, the www/mod_sendfile/Makefile has
>>> AP_GENPLIST= yes defined.  This causes the port to use this code to
>>> create the packing list:
>>>
>>> Mk/bsd.apache.mk
>>>
>>> 451     ap-gen-plist:
>>> 452     .if defined(AP_GENPLIST)
>>> 453     . if !exists(${PLIST})
>>> 454     @${ECHO} "===>  Generating apache plist"
>>> 455     # apache22
>>> 456     @${ECHO} "@unexec ${SED} -i '' -E
>>> '/LoadModule[[:blank:]]+%%AP_NAME%%_module/d'
>>> %D/%%APACHEETCDIR%%/httpd.conf">>  ${PLIST}
>>
>> Found the reason for this sed line, as it is used to remove the
>> LoadModule line from the httpd.conf file so that when Apache is
>> uninstalled, the httpd.conf could be removed, if there were no changes
>> from the original.
>>
>> see http://svnweb.freebsd.org/ports?view=revision&revision=194395
>>
>> I still think it is better to disable the module on uninstall, and
>> enable the module on install.
>>
>
> Hi Scot,
>
> have you also read the commit log?
> - Fix leftover httpd.conf for AP_GEN_PLIST using ports.  The problem is that
>    apxs does not remove module line from httpd.conf, it merely comments it out.
>    Later, on Apache deinstall, the file differs from stock httpd.conf and is not
>    deleted.
>
> The issue is the following.
> In case the LoadModule line is not removed from httpd.conf the port will be marked as broken by the ports build system.
>
>
> I'm thinking about an parameter which change the semantic in bsd.apache.mk so the module can be installed enabled.
> For example the following will do that (quick hack)
>
> Index: bsd.apache.mk
> ===================================================================
> --- bsd.apache.mk       (revision 309921)
> +++ bsd.apache.mk       (working copy)
> @@ -455,7 +445,11 @@
>   # apache22
>          @${ECHO} "@unexec ${SED} -i '' -E '/LoadModule[[:blank:]]+%%AP_NAME%%_module/d' %D/%%APACHEETCDIR%%/httpd.conf">>  ${PLIST}
>          @${ECHO} "%%APACHEMODDIR%%/%%AP_MODULE%%">>  ${PLIST}
> +.if defined(AP_MODENABLE)
> +       @${ECHO} "@exec %D/sbin/apxs -e -a -n %%AP_NAME%% %D/%F">>  ${PLIST}
> +.else
>          @${ECHO} "@exec %D/sbin/apxs -e -A -n %%AP_NAME%% %D/%F">>  ${PLIST}
> +.endif
>          @${ECHO} "@unexec echo \"Don't forget to remove all ${MODULENAME}-related directives in your httpd.conf\"">>  ${PLIST}
>   .      endif
>   .else

According to what was said in previous e-mails, there are several ways 
to handle install / deinstall:

1] add #LoadModule line commented on install and remove this line only 
if it is still commented (no user change made)

2] do not add anything, print the LoadModule line as pkg-message on 
install (this is standard way used by another ports to inform users what 
changes must be made to activate some port), do not remove anything on 
deinstall, print info message to remove line (similar to @unexec message 
above)

3] add LoadModule line uncommented on install (enable modul by default) 
and remove the line on uninstall


I prefere second or first variant. Somebody may not be happy to have 
modules enabled by default (the same policy as for not enabling services 
in rc.conf, not adding cronjobs or changes in periodic.conf)

My first try was to change @unexec sed line to:

@${ECHO} "@unexec ${SED} -i '' -E 
'/^#LoadModule[[:blank:]]+%%AP_NAME%%_module/d' 
%D/%%APACHEETCDIR%%/httpd.conf" >> ${PLIST}


It will produce following line in +CONTENTS

@unexec /usr/bin/sed -i '' -E 
'/^#LoadModule[[:blank:]]+xsendfile_module/d' %D/etc/apache22/httpd.conf


The problem is, that apxs line is working as switch:

@exec %D/sbin/apxs -e -A -n xsendfile %D/%F

First call adds LoadModule line and second removes it. So if the line is 
still there on next install, apxs is removing the line instead of left 
it untouched.

I don't have time to track it down right know. I will try to investigate 
it later today or tomorrow.

Miroslav Lachman