doctl compute ssh fails on ubuntu 20.04 with snap

[llimllib]

Describe the Issue:

doctl compute ssh fails on a nearly-vanilla ubuntu 20.04 system

1. Install doctl in the recommended way from a snap on a nearly-vanilla ubuntu 20.04
2. log in with doctl auth init
3. try to ssh into a server, and see it fail:

$ doctl compute ssh <servername>
/etc/ssh/ssh_config: line 19: Bad configuration option: include
/etc/ssh/ssh_config: terminating, 1 bad configuration options
Error: exit status 255

Environment:

• doctl version:

doctl version 1.43.0-release
Git commit hash: 1b6d0b8

• OS: Ubuntu 20.04
• Installation method: snap

Seems very related to #385; ssh works fine in the non-snap version

[andrewsomething]

Unfortunately, support for include directives was added in OpenSSH 7.3, but the version of OpenSSH provided by the Snap core is only 7.2.

$ cd ~
asb@asb-home:~$ snap run --shell doctl
To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.

asb@asb-home:/home/asb$ ssh -V
OpenSSH_7.2p2 Ubuntu-4ubuntu2.8, OpenSSL 1.0.2g  1 Mar 2016

From: https://www.openssh.com/txt/release-7.3

New Features

• ssh(1): Add an Include directive for ssh_config(5) files.

There is a related bug upstream: https://bugs.launchpad.net/snappy/+bug/1871827

When snapcraft 4.0 is promoted to stable, the core20 base snap will be supported. Switching to that for our package should pull in the new version.

https://snapcraft.io/docs/base-snaps
https://forum.snapcraft.io/t/release-notes-snapcraft-4-0/17515

[andrewsomething]

I've published a pre-release build using a core20 base Snap to the doctl edge channel. If anyone is experiencing this issue and can not use one of the existing work-a-rounds, you can install this version using:

snap install --channel=edge doctl

Or update from the stable version with:

snap refresh --channel=edge doctl