HOWTO: Automatically import your public SSH keys into LXD Instances

Just another reason why LXD is so awesome…

You can easily configure your own cloud-init configuration into your LXD instance profile.

In my case, I want cloud-init to automatically ssh-import-id kirkland, to fetch my keys from Launchpad.  Alternatively, I could use gh:dustinkirkland to fetch my keys from Github.

Here’s how!

First, edit your default LXD profile (or any other, for that matter):

$ lxc profile edit default

Then, add the config snippet, like this:

config:
  user.vendor-data: |
    #cloud-config
    users:
      - name: root
        ssh-import-id: gh:dustinkirkland
        shell: /bin/bash
description: Default LXD profile
devices:
  eth0:
    name: eth0
    nictype: bridged
    parent: lxdbr0
    type: nic
name: default

Save and quit in your interactive editor, and then launch a new instance:

$ lxc launch ubuntu:x
Creating amazed-manatee
Starting amazed-manatee

Find your instance’s IP address:

$ lxc list
+----------------+---------+----------------------+----------------------------------------------+------------+-----------+
|      NAME      |  STATE  |         IPV4         |                     IPV6                     |    TYPE    | SNAPSHOTS |
+----------------+---------+----------------------+----------------------------------------------+------------+-----------+
| amazed-manatee | RUNNING | 10.163.22.135 (eth0) | fdce:be5e:b787:f7d2:216:3eff:fe1c:773 (eth0) | PERSISTENT | 0         |
+----------------+---------+----------------------+----------------------------------------------+------------+-----------+

And now SSH in!

$ ssh ubuntu@10.163.22.135
$ ssh -6 ubuntu@fdce:be5e:b787:f7d2:216:3eff:fe1c:773

Enjoy!

:-Dustin