Debian Bug report logs - #516482
libvirt0: qemu+ssh requires netcat-openbsd

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Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Adrian Bridgett <adrian@smop.co.uk>

To: submit@bugs.debian.org

Subject: libvirt0: qemu+ssh requires netcat-openbsd

Date: Sat, 21 Feb 2009 20:03:09 +0000

Package: virt-manager
Version: 0.6.1-4
Severity: minor

It's taken me many hours to track this down, not sure the best way
(well, possibly remove the dependency!).

If you use qemu+ssh to a remote system, it calls "nc -U
/var/run/libvirt/libvirt-sock".

a) it should probably call "netcat" instead (I know we keep 'nc' for
backwards compatability, but I think 'netcat' has also been adopted
everywhere now (i.e. by other distros)).

b) -U is only supported by netcat-openbsd, not netcat-traditional
(perhaps mention this in the 'details' error message?)

c) not convinced what this actually does TBH - isn't that file 'owned'
by libvirt - i.e. couldn't it just be 'cat'ted instead hence removing
this dependency?

Anyway, set to minor, just hopefully saving someone else some
frustrations!

Many thanks :-)

Adrian
-- 
Email: adrian@smop.co.uk  -*-  GPG key available on public key servers
Debian GNU/Linux - the maintainable distribution   -*-  www.debian.org

Message #10 received at 516482@bugs.debian.org (full text, mbox, reply):

From: Guido Günther <agx@sigxcpu.org>

To: adrian@smop.co.uk, 516482@bugs.debian.org

Subject: Re: [Pkg-libvirt-maintainers] Bug#516482: libvirt0: qemu+ssh requires netcat-openbsd

Date: Sun, 22 Feb 2009 13:59:59 +0100

On Sat, Feb 21, 2009 at 08:03:09PM +0000, Adrian Bridgett wrote:
> Package: virt-manager
> Version: 0.6.1-4
> Severity: minor
> 
> It's taken me many hours to track this down, not sure the best way
> (well, possibly remove the dependency!).
> 
> If you use qemu+ssh to a remote system, it calls "nc -U
> /var/run/libvirt/libvirt-sock".
> 
> a) it should probably call "netcat" instead (I know we keep 'nc' for
> backwards compatability, but I think 'netcat' has also been adopted
> everywhere now (i.e. by other distros)).
> 
> b) -U is only supported by netcat-openbsd, not netcat-traditional
> (perhaps mention this in the 'details' error message?)
> 
> c) not convinced what this actually does TBH - isn't that file 'owned'
> by libvirt - i.e. couldn't it just be 'cat'ted instead hence removing
> this dependency?
> 
> Anyway, set to minor, just hopefully saving someone else some
> frustrations!
We do have a "Recommends: netcat-openbsd" in libvirt-bin exactly for
that so the only point left is improving the error message or am I
missing something?
 -- Guido

Message #15 received at 516482@bugs.debian.org (full text, mbox, reply):

From: Adrian Bridgett <adrian@smop.co.uk>

To: Guido Günther <agx@sigxcpu.org>

Cc: 516482@bugs.debian.org

Subject: Re: [Pkg-libvirt-maintainers] Bug#516482: libvirt0: qemu+ssh requires netcat-openbsd

Date: Sun, 22 Feb 2009 13:07:49 +0000

Ah, I hadn't spotted that. 

Probably just the error message in that case (I had to strace it to
figure out what was going wrong - if the error that came back from the
exec was displayed it would have been a 2min job).

Adrian
-- 
Email: adrian@smop.co.uk  -*-  GPG key available on public key servers
Debian GNU/Linux - the maintainable distribution   -*-  www.debian.org

Message #20 received at 516482@bugs.debian.org (full text, mbox, reply):

From: Laurent Léonard <laurent@open-minds.org>

To: 516482@bugs.debian.org

Date: Mon, 16 Mar 2009 15:49:02 +0100

Virsh prints the error message given by nc :
$ virsh -c qemu+ssh://root@host/system
nc: invalid option -- U
nc -h for help
error: failed to connect to the hypervisor

But it could be replaced by a more human friendly error message. Same with the 
generic dialog from Virt-manager about a "libvirtd" problem...

-- 
Laurent Léonard

Message #25 received at 516482@bugs.debian.org (full text, mbox, reply):

From: Guido Günther <agx@sigxcpu.org>

To: Laurent Léonard <laurent@open-minds.org>, 516482@bugs.debian.org

Subject: Re: [Pkg-libvirt-maintainers] Bug#516482: (no subject)

Date: Tue, 17 Mar 2009 16:46:02 +0100

On Mon, Mar 16, 2009 at 03:49:02PM +0100, Laurent Léonard wrote:
> Virsh prints the error message given by nc :
> $ virsh -c qemu+ssh://root@host/system
> nc: invalid option -- U
> nc -h for help
> error: failed to connect to the hypervisor
> 
> But it could be replaced by a more human friendly error message. Same with the 
> generic dialog from Virt-manager about a "libvirtd" problem...
I agree that error handling could be improved a lot here. Patches are of
course welcome.
Cheers,
 -- Guido

Message #30 received at 516482@bugs.debian.org (full text, mbox, reply):

From: Jan Rasche <xcomm@linux-hacks.com>

To: 516482@bugs.debian.org

Subject: nc -U / netcat-openbsd

Date: Wed, 06 May 2009 15:53:26 +0200

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


Hi virt-manager Developers,

Just spend some hours with virt-manager from my Debian GNU/Notebook not
being able to connect to two OpenSuSE 11.1 Xen hosts.

###GUI###
virt-manager from GUI tells nothing about the real reason:

Unable to open a connection to the libvirt management daemon.

Libvirt URI is: xen+ssh://root@foobar/

Verify that:
 - The 'libvirtd' daemon has been started

Unable to open connection to hypervisor URI 'xen+ssh://root@foobar/':
<class 'libvirt.libvirtError'> server closed connection
None

Maybe you need to install ssh-askpass in order to authenticate.



###Shell###
virsh # connect xen+ssh://root@foobar/
bash: nc: command not found
error: Failed to connect to the hypervisor
error: server closed connection


foobar# ln -s /usr/bin/netcat /usr/bin/nc


virsh # connect xen+ssh://root@foobar/
nc: invalid option -- 'U'
nc -h for help
error: Failed to connect to the hypervisor
error: server closed connection


Finding http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=516482 through
friend Google.


foobar# zypper install netcat-openbsd


virsh # connect xen+ssh://root@foobar/

virsh # list --all
...



After all this was coming down to netcat-openbsd needed on the remote
machines. I don't think relying on such a dependency is good practice
beneath no specific error at all given when in GUI.


 For my part I would raise the severity of this bug here.

Best regards, Jan


- --
- --

"Eigentlich bin ich ganz anders...
...nur komme ich so selten dazu."

* [http://en.wikipedia.org/wiki/Ödön_von_Horváth Ödön von Horváth]
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Message #35 received at 516482@bugs.debian.org (full text, mbox, reply):

From: Dean Hamstead <dean.hamstead@optusnet.com.au>

To: 516482@bugs.debian.org

Subject: libvirt0: qemu+ssh requires netcat-openbsd

Date: Wed, 28 Jul 2010 14:49:56 +1000

in 0.8.4 i have had to swap back from netcat-openbsd to netcat-traditional

as netcat-openbsd doesnt support the '-q' option

can libvirtd query netcat first to determine the implementation?

perhaps the -q option can be added to netcat-openbsd?

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