Bug 1133686

Summary: virt-sandbox-service create -N dhcp does not work
Product: [Fedora] Fedora Reporter: Gene Czarcinski <gczarcinski>
Component: libvirt-sandboxAssignee: Daniel Berrangé <berrange>
Status: CLOSED ERRATA QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: unspecified    
Version: 21CC: berrange, dwalsh, mprivozn, virt-maint
Target Milestone: ---Keywords: Upstream
Target Release: ---   
Hardware: x86_64   
OS: Linux   
Whiteboard:
Fixed In Version: libvirt-glib-0.2.1-1.fc22 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2015-07-14 15:48:44 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Attachments:
Description Flags
bugfix for starting dhclient
none
get more info about dhclient starting none

Description Gene Czarcinski 2014-08-25 20:06:52 UTC 
Description of problem:
The documentation for sandbox networking: http://sandbox.libvirt.org/networking/ says that if I specify -N dhcp,source=<virtual_network> that dhclient would be started in the container to acquire and setup the network.  This does not currently work.

If I specify -N \ source=net1,address=192.168.1.90/24,route=192.168.1.255%192.168.1.1

and "net1" is defined as a virtual (nat) network or a bridge to a host network which has dnsmasq running for dhcp & dns, the static specification works but the dhcp does not.

Version-Release number of selected component (if applicable):
Fedora 20 + fedora-virt-preview with libvirt-sandbox-0.5.1-4.fc20.x86_64

How reproducible:
everytime

Steps to Reproduce:
1. create a secure container with -N dhcp,...
2. after starting it, connect and do "ip addr"
3. repeat with -N address=...

Actual results:
no IP when dhcp specify; Ip assigned and started with static address

Expected results:
IP address assigned and started with both

Additional info:
Comment 1 Gene Czarcinski 2014-09-06 18:23:23 UTC 
OK, I believe I have tracked down the problem ... not a fix but the problem anyway.  In libvirt-sandbox-init-common.c, the start_dhcp() function dot not work!  That is, it is not starting dhclient for a dhcp network device.

I was wondering why there was no dhclient running for the dhcp NIC but ??  I tried starting my own copy after doing a connect with:
   /sbin/dhclient --no-pid eth1 &
Slam, bang, I suddenly had a dhcp IP address on interface eth1!!!

This is not a fix.  Now I need to look into g_spawn_async().
Comment 2 Gene Czarcinski 2014-09-09 17:11:50 UTC 
After a lot more "instrumenting" and testing I believe I have a potential fix.  I finally tried replacing the g_spawn_async() in start_dhcp() with g_spawn_sync() and (suddenly) dhcp works!

I created /usr/sbin/dhclient.sh which I then invoked the real /usr/sbin/dhclient.  When g_spawn_async() was used, the actual program did not start.  But, replacing it with g_spawn_sync() worked.

Now let's see if I can create a simple patch to fix things.
Comment 3 Gene Czarcinski 2014-09-10 17:56:54 UTC 
Created attachment 936277 [details]
bugfix for starting dhclient
Comment 4 Gene Czarcinski 2014-09-10 17:57:43 UTC 
Created attachment 936278 [details]
get more info about dhclient starting
Comment 5 Michal Privoznik 2014-11-05 11:46:27 UTC 
I've just pushed the patches upstream:

commit bf2bb41091cf8271af1c1790001858d58e5f49c8
Author:     Gene Czarcinski <gczarcinski.com>
AuthorDate: Fri Oct 31 14:02:53 2014 -0400
Commit:     Michal Privoznik <mprivozn>
CommitDate: Wed Nov 5 11:51:51 2014 +0100

    v1.1 add -v to dhclient parameter arguments
    
    This patch improves the ability to understand what is happening
    with dchlient and is obviously optional.

commit 25590372c87bce1b91bce7ba701f32efd79df9dc
Author:     Gene Czarcinski <gczarcinski.com>
AuthorDate: Fri Oct 31 14:02:52 2014 -0400
Commit:     Michal Privoznik <mprivozn>
CommitDate: Wed Nov 5 11:51:43 2014 +0100

    v1.1 for dhclient use g_spawn_sync()
    
    This patch addresses problem RHBZ #1133686.
    
    For some (unknown to me) reason, g_spawn_async() is not
    starting dhclient so that a dhcp NIC can be configured.
    However, simply using g_spawn_sync() works.  This was the
    only use of g_spawn_async().
    
    Note: There is no problem using sync instead of async since dhclient will
    disconnect and put itself in the background once the network is started.

v0.5.1-15-gbf2bb41
Comment 6 Gene Czarcinski 2014-12-06 15:52:14 UTC 
Any idea as to when an updated libvirt-sandbox will be issued?  The last update was over a year ago.
Comment 7 Fedora Update System 2015-07-01 18:15:21 UTC 
libvirt-glib-0.2.1-1.fc22, libvirt-sandbox-0.6.0-1.fc22 has been submitted as an update for Fedora 22.
https://admin.fedoraproject.org/updates/libvirt-glib-0.2.1-1.fc22,libvirt-sandbox-0.6.0-1.fc22
Comment 8 Fedora Update System 2015-07-03 18:50:19 UTC 
Package libvirt-glib-0.2.1-1.fc22, libvirt-sandbox-0.6.0-1.fc22:
* should fix your issue,
* was pushed to the Fedora 22 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing libvirt-glib-0.2.1-1.fc22 libvirt-sandbox-0.6.0-1.fc22'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/FEDORA-2015-11131/libvirt-glib-0.2.1-1.fc22,libvirt-sandbox-0.6.0-1.fc22
then log in and leave karma (feedback).
Comment 9 Fedora Update System 2015-07-14 15:48:44 UTC 
libvirt-glib-0.2.1-1.fc22, libvirt-sandbox-0.6.0-1.fc22 has been pushed to the Fedora 22 stable repository.  If problems still persist, please make note of it in this bug report.