[nycbug-talk] rc.conf / rc'ng hacking

[Matthew Story]

On Oct 13, 2011, at 11:32 AM, Mark Saad wrote:
> So I was tired,lazy yesterday and I was wondering how does rc'ng
> handle this , surely there has to be a rc'ng function to suck in from
> rc.subr that I can call to get my nic type etc . I cant find anything,
> can someone shed some light on how this handled ? Is there an easier
> way to this ?

you could use /etc/rc.conf.local, from man 5 rc.conf

     The /etc/rc.conf file is included from the file /etc/defaults/rc.conf,
     which specifies the default settings for all the available options.
     Options need only be specified in /etc/rc.conf when the system adminis-
     trator wishes to override these defaults.  The file /etc/rc.conf.local is
     used to override settings in /etc/rc.conf for historical reasons.  See
     the rc_conf_files variable below.

if you need more facility than that, you can alter the rc_conf_files variable in /etc/defaults/rc.conf:

rc_conf_files="/etc/rc.conf /etc/rc.conf.local"

for your inst script, you could start with the old rc_conf_files setting, and then  ...

awk -F '=' 'BEGIN { OFS=FS; } $1 == "rc_conf_files" { sub(/\"$/, " my.rc.conf.local\"", $2); } { print; }' /etc/defaults/rc.conf > /etc/defaults/rc.conf.new && mv /etc/defaults/rc.conf.new /etc/defaults/rc.conf

will add 'my.rc.conf.local" to the rc_conf_files string.  As rc conf files are just shell, you could cp the rc_conf_files functionallity from defaults to your /etc/rc.conf file and preserve the defaults file (as suggested in the defaults documentation), relevant code from rc.conf below:

##############################################################
### Define source_rc_confs, the mechanism used by /etc/rc.* ##
### scripts to source rc_conf_files overrides safely.       ##
##############################################################

if [ -z "${source_rc_confs_defined}" ]; then
    source_rc_confs_defined=yes
    source_rc_confs () {
        local i sourced_files
        for i in ${rc_conf_files}; do
            case ${sourced_files} in
            *:$i:*)                ;;  
            *)  
                sourced_files="${sourced_files}:$i:"
                if [ -r $i ]; then
                    . $i
                fi  
                ;;              esac
        done
    }   
fi

if you care less for safety, you can just:

[ -r "rc.special.conf" ] && . "rc.special.conf"

or in your /etc/rc.conf, breakout your service daemon specific configs and then do the same pattern:

# for apache
[ -r "/etc/rc.conf.apache" ] && . "/etc/rc.conf.apache"
# for sendmail
[ -r "/etc/rc.conf.sendmail" ] && . "/etc/rc.conf.sendmail"
# etc ...


> 
> ---
> Mark Saad | mark.saad at ymail.com
> _______________________________________________
> talk mailing list
> talk at lists.nycbug.org
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> 

best of luck.

-matt