Failure when deploying on lxd models and model name contains space characters

[Francesco Banconi]

For instance, on a newly bootstrapped lxd controller:

% juju create-model "foo bar"
created model "foo bar"
% juju switch "foo bar"
local.lxd:foo bar (no change)
% juju deploy wordpress
Added charm "cs:trusty/wordpress-4" to the model.
Deploying charm "cs:trusty/wordpress-4" with the charm series "trusty".

But then:
% juju status
...
[Units]
wordpress/0 error lost cannot assign unit "wordpress/0" to machine: cannot assign unit "wordpress/0" to new machine or container: cannot assign unit "wordpress/0" to new machine: Error inserting juju-foo bar into database: UNIQUE constraint failed: profiles.name
...

Moreover, after the above is run, it's also not possible to destroy the controller:
% juju destroy-controller lxd --destroy-all-models -y
Destroying controller
Waiting for hosted model resources to be reclaimed
Waiting on 2 models, 1 service
Waiting on 1 model, 1 service
Waiting on 1 model, 1 service
Waiting on 1 model, 1 service
Waiting on 1 model, 1 service
... [for ever]

I had to manually lxc delete -f ... and kill the controller.

Note that it could be potentially common for users to create models with such names, as it's very easy for instance when using the Juju GUI.

[Francesco Banconi (frankban)]

This is surely related on the lxd provider, but also part of a more generic lack of input validation when creating new models.

[Francesco Banconi (frankban)]

Also note that website exposing URL paths which include the model name would be broken without input validation (for instance, a model can be named "#...".

[Horacio Durán (hduran-8)]

The important question here is, what is the policy we are going to choose.
Should we forbid names with spaces/special characters or should we add extreme support for them? (escaping chars, replacing chars) I would go for a limiting approach, the other one opens the door to many more hiden issues.

[Mick Gregg (macgreagoir)]

On the limiting approach, may I suggest the unreserved characters from RFC3986 (https://www.ietf.org/rfc/rfc3986.txt)? "[U]ppercase and lowercase letters, decimal digit, hyphen, period, underscore, and tilde." These should be URL- and Bash-safe. Is this set too limiting?

[Tim Penhey (thumper)]

I would go one step further, and say lowercase, digit and hyphen.

[Mick Gregg (macgreagoir)]

PR https://github.com/juju/juju/pull/5470

[Mick Gregg (macgreagoir)]

There are now two PRs
  * https://github.com/juju/juju/pull/5470/
  * https://github.com/juju/names/pull/66

[Mick Gregg (macgreagoir)]

The question has been raised as to how well we can align naming rules for features. The current PRs have lowercase, digit and hyphen (from comment #5). The user names rule allows these and also upper case letters, plus sign and dot. Are user and model names worth aligning, at least, or are there reasons to keep model names more limited?