On 4/3/15, 12:30 PM, "Nishanth Aravamudan" <n...@linux.vnet.ibm.com> wrote:
>On 03.04.2015 [02:17:17 +0000], Britt Houser (bhouser) wrote: >> I'm working on a RHEL7 docker container with cobbler in it. I have >>setup >> cobbler in this container to manage dhcpd. > >It seems like you're not configuring the containers correctly. Cobbler >should run in one container and dhcpd should run in another, right? > >Dare I ask why you're doing this? :) Right - not the container ideal, but I put the "why" further down. > >> One hurdle with this setup is that a cobbler sync needs to restart >> dhcpd, but a docker container has no systemd. So what I've done to >> work around this is to edit >> >>/usr/lib/python2.7/site-packages/cobbler/modules/sync_post_restart_servic >>es >> .py and change the dhcp_restart_command to call a simple shell >> script: >> >> -- >> #!/bin/sh >> >> #dhcpd writes its pid to /var/run/dhcpd.pid >> #kill the PID in the file, if the file exists >> if [ -f "/var/run/dhcpd.pid" ] >> then >> kill `cat /var/run/dhcpd.pid` >> fi >> >> #Start again using command line from >>/usr/lib/systemd/system/dhcpd.service >> /usr/sbin/dhcpd -cf /etc/dhcp/dhcpd.conf -user dhcpd -group dhcpd >> -- >> >> I do realize I'm not really supposed to have more than one process in a >> container. But if I put dhcpd in its own container, the problem would >>just >> be even harder b/c now cobbler in its container needs to restart another >> container. > >No, it just needs to restart (reload) that process. Meaning dhcpd needs >either graceful reload, or, as you said, you need to be able to restart >the DHCP process itself. Containerization isn't free :) So to my knowledge, ISC-DHCP doesn't have a "reload", you must kill and then restart. If DHCP is in its own container, killing the process means killing the container. Respawning the process means starting a new container. This in and of itself isn't hard, but invoking that from within another container I think would be more difficult than keeping both processes in the same container. > >> So I took the easier route and put them in the same container. >> So in this implementation, it would be useful if I could specify a >>custom >> dhcp_restart_command in /etc/cobbler/settings. Would that be a change >>the >> community would be interested in accepting? > >I think the right way is to provide another option to the > >[dhcp] >module = manage_isc > >section of configuration, which is something like > >[dhcp] >module = manage_local > >And configure that appropriately? I've done that, for instance, for >having a local version of authentication. > >-Nish Can you elaborate on what you envision manage_local would do? I'm not quite following how this would work? I still want cobbler to be generating my dhcpd.conf file from template, I just want to change how cobbler restarts dhcpd. Thx, britt _______________________________________________ cobbler-devel mailing list cobbler-devel@lists.fedorahosted.org https://lists.fedorahosted.org/mailman/listinfo/cobbler-devel
