Libguestfs - Jan 2016 - Re: v2v: error while killing ssh-agent after importing VM via xen+ssh

Hi,

I am successfully importing VM from Xen server at oVirt project via virt-v2v.
I am setting ssh-agent and running ssh-add before the import process,
after the import done I am trying to kill the agent via:
ssh-agent -k (and setting the SSH_AGENT_PID environment), but I get the
following error:
kill: No such process

Can you please explain why there is no agent?
Do I need to delete the agent?

btw I am also running 'ssh-add -d' after the import process with no
problems.

Thank you,

 Shahar.

On Wed, Jan 13, 2016 at 09:55:53AM +0200, Shahar Havivi
wrote:
> Hi,
> 
> I am successfully importing VM from Xen server at oVirt project via
virt-v2v.
> I am setting ssh-agent and running ssh-add before the import process,
> after the import done I am trying to kill the agent via:
> ssh-agent -k (and setting the SSH_AGENT_PID environment), but I get the
> following error:
> kill: No such process
> 
> Can you please explain why there is no agent?
When you run:

   eval `ssh-agent`

ssh-agent starts up and creates several environment variables (which
are added to the environment, because you use the eval `..`).
In particular it sets SSH_AGENT_PID to its own PID.

ssh-agent -k is supposed to read SSH_AGENT_PID from the environment
and kill the previously started ssh-agent process, basically killing
that PID.

It works for me and for lots of other people, so I'm guessing you must
either be running ssh-agent wrongly the first time, or getting the
SSH_AGENT_PID environment variable mixed up somewhere.
> Do I need to delete the agent?
Not necessarily, but if you don't kill the agent then two bad things
can happen: (1) You get lots of ssh-agent processes building up
(2) The ssh-agent processes may be storing your unencrypted private
keys.  Except that ...
> btw I am also running 'ssh-add -d' after the import process with no
problems.
... ssh-add -d will remove the private key from the agent.  However
the agent should still be running after this, so it would have no
effect on whether ssh-agent -k would succeed.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://people.redhat.com/~rjones/virt-df/

On 13.01.16 10:27, Richard W.M. Jones wrote:
> On Wed, Jan 13, 2016 at 09:55:53AM +0200, Shahar Havivi wrote:
> > Hi,
> > 
> > I am successfully importing VM from Xen server at oVirt project via
virt-v2v.
> > I am setting ssh-agent and running ssh-add before the import process,
> > after the import done I am trying to kill the agent via:
> > ssh-agent -k (and setting the SSH_AGENT_PID environment), but I get
the
> > following error:
> > kill: No such process
> > 
> > Can you please explain why there is no agent?
> 
> When you run:
> 
>    eval `ssh-agent`
I didn't run eval `ssh-agent` but ssh-agnet and then ssh-add (I needed the
SSH_AUTH_SOCK that return from ssh-agent since I am running two different
processes).
I guess I can read the environment SSH_AUTH_SOCK after run eval `ssh-agent`...

do you think there is a different between running with to without eval?
 
  Shahar.
> 
> ssh-agent starts up and creates several environment variables (which
> are added to the environment, because you use the eval `..`).
> In particular it sets SSH_AGENT_PID to its own PID.
> 
> ssh-agent -k is supposed to read SSH_AGENT_PID from the environment
> and kill the previously started ssh-agent process, basically killing
> that PID.
> 
> It works for me and for lots of other people, so I'm guessing you must
> either be running ssh-agent wrongly the first time, or getting the
> SSH_AGENT_PID environment variable mixed up somewhere.
> 
> > Do I need to delete the agent?
> 
> Not necessarily, but if you don't kill the agent then two bad things
> can happen: (1) You get lots of ssh-agent processes building up
> (2) The ssh-agent processes may be storing your unencrypted private
> keys.  Except that ...
> 
> > btw I am also running 'ssh-add -d' after the import process
with no problems.
> 
> ... ssh-add -d will remove the private key from the agent.  However
> the agent should still be running after this, so it would have no
> effect on whether ssh-agent -k would succeed.
> 
> Rich.
> 
> -- 
> Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
> Read my programming and virtualization blog: http://rwmj.wordpress.com
> virt-df lists disk usage of guests without needing to install any
> software inside the virtual machine.  Supports Linux and Windows.
> http://people.redhat.com/~rjones/virt-df/