Image location error is incomprehensible

[niemeyer]

Tried this today:

$ lxc launch images:ubuntu/16.04
error: Only full and short (12 chars) hashes are supported by this server

This should really say "image not found" or similar.

[stgraber]

It would if the image server you were talking to wasn't a static apache2 web server :)

[stgraber]

images: isn't running LXD at all, it's a static web server with some clever rewrite rules.

The source of the error you're getting is because it doesn't know if you typed a partial hash (where we only support full length or 12 chars length in our fake server) or if you requested something which doesn't exist at all.

[niemeyer]

I'm sure there are excellent technical reasons why it doesn't work. My only point is that this is a terrible message which should be fixed taking in account that it's a user sitting at the terminal, rather than a developer. There's nothing in that location, and I should try another one.

[niemeyer]

Suggested message: error: image not found

[stgraber]

That error message would be rather confusing to people doing:

lxc launch images:850b

Which is an existing image and would be absolutely valid on any real LXD server.

[niemeyer]

I don't understand the point. If it is an existing image, then the image exists and you should not display this error.

[stgraber]

The server is a static web server, it doesn't know how to match partial hashes.

Anyway, I changed the error to:

error: not found (not a fingerprint, partial fingerprint (first 12 chars) or valid alias)

That will have to do.

[niemeyer]

Thanks, that's way more clear. Might be worth mentioning what was not found.

Note that the fact a static web server is backing it is somewhat irrelevant. The lxc tool can do whatever it wants to present reasonable information to the user.

[mikescott]

For anybody (like me) who arrived here through Google and is trying to create lxd containers with Ansible, it's because their current documentation is wrong.

I wanted to use images:debian/stretch. Their main example for images: is:

# An example for creating a Ubuntu container and install python
- hosts: localhost
  connection: local
  tasks:
    - name: Create a started container
      lxd_container:
        name: mycontainer
        state: started
        source:
          type: image
          mode: pull
          server: https://images.linuxcontainers.org
          protocol: lxd
          alias: ubuntu/xenial/amd64
        profiles: ["default"]
        wait_for_ipv4_addresses: true
        timeout: 600

So I tried changing alias to "debian/stretch" and "images:debian/stretch" but got the cryptic error above.

As stgraber mentioned this is because images: is not running lxd, so the protocol setting needs to be "simplestreams", and the correct alias would be "debian/stretch".