juju ssh with proxy-ssh/--proxy uses incorrect address

[Andrew Wilkins]

https://github.com/juju/juju/commit/d25d100f3c04eb6dc22c58db51e87c1d947a6836 changed the Juju CLI so that the proxy-ssh model config and --proxy flag to SSH-related commands are ignored.

Because of this change, you can no longer SSH to a machine without a directly accessible IP. We don't necessarily need to have public IPs for all instances; only those that are exposed.

Reported by Gabriel Samfira.

[Greg Lutostanski (lutostag)]

This is an issue for at least the following public clouds:
 aws
 gce
 rackspace

Against these clouds the following commands will fail:
juju bootstrap
juju deploy ubuntu
juju wait
juju ssh ubuntu/0 # neither juju ssh --proxy ubuntu/0

[Greg Lutostanski (lutostag)]

(the ssh commands are what fails above from the repro above)

[Menno Finlay-Smits (menno.smits)]

@lutostag: Are you sure that your issue is the same as Gabriel's? It seems you're having trouble both with and without proxy support being enabled - or do you have the "proxy-ssh" option set? It isn't clear from what you've written.

Gabriel's issue is relates to this area:

https://github.com/juju/juju/commit/d25d100f3c04eb6dc22c58db51e87c1d947a6836#diff-f75a59a4d41206aca31bb545d00e3e31R326

Even though proxy-ssh or --proxy is used reachability is still checked from the client which is silly and will fail if instances don't have public addresses.

I'm exploring some possible fixes now.

[Menno Finlay-Smits (menno.smits)]

Fix is here: https://github.com/juju/juju/pull/7151

Follow on ticket is here: https://bugs.launchpad.net/juju/+bug/1676670