Re: [libvirt] DHCP and secure containers

On 09/03/2014 09:42 AM, Gene Czarcinski wrote: > On 09/02/2014 06:37 AM, Gene Czarcinski wrote: >> OK, hopefully this mailing list is more active and I can get some >> response to my questions. >> --------------------------------------------------------------------------------------------------------------------- >> >> I have been "playing with" Secure Containers running a lighttpd >> server and have it up and running. I used Adam's process >> (https://www.happyassassin.net/2014/07/23/bridged-networking-for-libvirt-w...) >> for getting a bridge defined when also running NetworkManager. I >> then created a virtual network definition: >>> <network> >>> <name>net18</name> >>> <uuid>8d19a05b-ac85-4e2a-88bc-5ca4cbb29a33</uuid> >>> <forward mode='bridge'/> >>> <bridge name='br0'/> >>> </network> >> This works fine when I use static addresses such as: >>> -N >>> source=net18,address=192.168.18.94/24,route=192.168.18.255%192.168.18.1 >>> >> but does not work when I specify using dhcp: >>> -N source=net18,dhcp >> I have reported this as a bug: >> https://bugzilla.redhat.com/show_bug.cgi?id=1133686 >> >> Since there has not been much of a reaction to the BZ report, I >> decided to take a look at the source code (it sure would have been >> nice if the SRPMS were there in the F20 fedora-virt-preview but I >> get the package from development/21). >> >> I see that libvirt-sandbox-init-common.c has the code for starting >> dhcp and also has main() along with some runtime options for -v >> verbose and -d debug. >> >> OK, how do I go about turning verbose and/or debug on? >> >> Any suggestions on how to debug and get dhcp to work? I not only >> want to find the problem but to fix the problem if needed. > While I have not figured out how to get dhcp to work with a secure > container create by virt-sandbox-service, I have gotten a container > working with the network up and a dhcp assigned IP using the lxc-* > commands and following this procedure: > https://sysadmincasts.com/episodes/24-introduction-to-containers-on-linux... > > to create a "busybox" container. The network came up automatically. > > Following the procedure in this tutorial: > https://major.io/2014/04/21/launch-secure-lxc-containers-on-fedora-20-usi... > > I created and installed a test container. I had to add ifcfg-eth0 > for a simple network and then run "service network start" for the > netowrk to actually come up ... which it did with a DHCP (actually > dnsmasq) assigned IP address. Note that this procedure explicitly > installs the dhclient package. > > So, what am I doing "wrong" with secure containers? Or, is this a bug? > Ping!! Hello ... anybody out there?? To keep my sanity, would SOMEBODY PLEASE try doing a secure sandbox with a dhcp network and see if the network is started or not. My case: static network started, dhcpnetwork is NOT started (/sbin/dhclient is not running). Here is what I have done so far: 1. "Instrumented" libvirt-sandbox-init-common.c and libvirt-sandbox-init-lxc.c by turning on debug and adding a whole bunch of fprintf(stderr,...) statements to track the initialization. These say that start_dhcp() in libvirt-sandbox-init-common.c is executed successfully. Nevertheless, for some reason, the g_spawn_async() did not result in a running /sbin/dhclient. 2. So, I tried running dhclient myself. I had two networks defined: "-N <static-ip>,source=net18 -N dhcp,source=default". After connecting top the secure container, I did: /sbin/dhclient --no-pid eth1 which resulted in the network on eth1 starting with a 192.168.122.<n> address. 3. I then went a step further. I took the start_dhcp() code from libvirt-sandbox-init-common.c and encapsulated it with a wrapper to fake what was done in init-common.c but with its own main(). Compiled this and put the binary where I could execute it after doing the connect. Stop, start, and connect to the secure container. The network on eth1 is not started. Run my test_dhcp_start program and the result was the eth1 network is started and there is a dhclient running. Suggestions please!