[Note:] ssh agent forwarding

[Mike Wright]

Hi all,

There was a thread on here recently about ssh agent forwarding.  Usually 
I start it like this:

<code>
ssh-agent
ssh-add
</code>

I came across a situation where I couldn't establish a connection to the 
agent when I tried to "ssh-add" my keys.  ssh-agent had been executed 
already. It had somehow become discombobulated.

The solution was to invoke ssh-agent differently:

<code>
eval `ssh-agent -s`
ssh-add
</code>

Hope that saves somebody else some headaches ;D

Mike Wright

[Gordon Messmer]

On 07/28/2016 06:34 PM, Mike Wright wrote:
> Usually I start it like this:
> ssh-agent
> The solution was to invoke ssh-agent differently:
> eval `ssh-agent -s`

Yes, that's normal.  You need to either eval the output of ssh-agent or 
it must be the parent process of your shell.  (e.g. ssh-agent 
gnome-shell).  If you weren't doing that in the past, then the ssh-agent 
you invoked without "eval" wasn't the ssh-agent you were actually 
using.  GNOME provides its own agent, for instance, and you may have 
been using that.

[Christopher]

On Thu, Jul 28, 2016 at 10:24 PM Gordon Messmer 
wrote:
> On 07/28/2016 06:34 PM, Mike Wright wrote:
> > Usually I start it like this:
> > ssh-agent
> > The solution was to invoke ssh-agent differently:
> > eval `ssh-agent -s`
>
> Yes, that's normal.  You need to either eval the output of ssh-agent or
> it must be the parent process of your shell.  (e.g. ssh-agent
> gnome-shell).  If you weren't doing that in the past, then the ssh-agent
> you invoked without "eval" wasn't the ssh-agent you were actually
> using.  GNOME provides its own agent, for instance, and you may have
> been using that.

Agreed. Mike was almost certainly connecting to the one provided by
gnome-keyring-daemon (/run/user/<uid>/keyring/ssh), and the ssh-agent he
was launching wasn't being used at all.

As was pointed out in the previous thread, it seems there might be a race
condition, and sometimes this socket doesn't get created by
gnome-keyring-daemon when one logs in.

This has only happened to me in F24, and it has happened a few times since
I've upgraded. So far, I've found that simply logging out and logging back
in is usually sufficient to fix it. It is annoying, though, especially
since I don't see any errors from monkeysphere when it tries to inject my
auth keys into the agent and the agent isn't there.