Bug 1044331

Summary:	[RFE] allow to create a private network between VMs
Product:	[Retired] oVirt	Reporter:	Markus Stockhausen <mst>
Component:	vdsm	Assignee:	Dan Kenigsberg <danken>
Status:	CLOSED DUPLICATE	QA Contact:	yeylon <yeylon>
Severity:	medium	Docs Contact:
Priority:	unspecified
Version:	3.3	CC:	abaron, acathrow, bazulay, iheim, mgoldboi, mst, srevivo, yeylon
Target Milestone:	---	Keywords:	FutureFeature
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	network
Fixed In Version:		Doc Type:	Enhancement
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-02-24 16:22:35 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:

Description Markus Stockhausen 2013-12-18 06:25:22 UTC

Description of problem:

If you configure dummy network interfaces on a Fedora 19 host (e.g. dummy0, ...) they cannot be seen by OVirt. VDSM filters them out


Version-Release number of selected component (if applicable):
ovirt engine 3.3.1
ovirt hypervisor installed on Fedora 19


How reproducible:
100%


Steps to Reproduce:
permanently install dummy kernel module on Fedora 19 node
restart Fedora 19 node


Actual results:
interface dummy0 does not show up in OVirt

Expected results:
interface dummy0 should be visible

Additional info:
Seems to be a bug that vdsm filters out dummy interfaces. Workaround for the bug is to modify /usr/lib64/python2.7/site-packages/vdsm/config.py.

Replace 'fake_nics', 'dummy_*'
with  'fake_nics', 'dummy*'

Comment 1 Dan Kenigsberg 2013-12-18 09:41:07 UTC

That's not a bug, it's a feature ;-)

We do not want to fool Engine to think that these are true NICs, unless in special use cases. The configurational "fake_nics" was designed to allow you to add specific dummy devices which you'd like to report as real NICs. dummy_* are reported mostly because they are not common in real life, and they are used by our functional/networkTests suite.

Could you explain your use case? I'm inclined to close this issue as NOTABUG.

Comment 2 Markus Stockhausen 2013-12-18 09:45:08 UTC

I want to create a private network between two VMs that is not exposed to the real network infrastructure.

Comment 3 Itamar Heim 2013-12-18 11:06:01 UTC

could be a dup, but changing title to make request clear.

Comment 4 Dan Kenigsberg 2013-12-18 13:25:16 UTC

Your easiest workaround would be to set the name of your dummy device to something that Vdsm reports, such as in

   sudo ip link add dummy_1 type dummy

Another option is to use the new extnet Vdsm hook http://gerrit.ovirt.org/gitweb?p=vdsm.git;a=tree;f=vdsm_hooks/extnet;h=9866aa3279da4db3b006db2c80198762672fad7a;hb=35d5248af6fa0e6468e6232c52cfbb73d09d0562 
The latter would give you more control on the nature of the VM connectivity.

Comment 5 Dan Kenigsberg 2013-12-18 13:28:19 UTC

And yes, this bug is a clone of bug 988285 for rhevm.

Comment 6 Markus Stockhausen 2013-12-18 14:12:41 UTC

I will go with the ip link command. Modifying config.py seems to be no nice integration.

Comment 8 Dan Kenigsberg 2014-02-24 16:22:35 UTC

(In reply to Dan Kenigsberg from comment #5)
> And yes, this bug is a clone of bug 988285 for rhevm.

.. and since Vdsm can already create a bridged network with no physical nics, there's nothing much to do here.

*** This bug has been marked as a duplicate of bug 988285 ***