bootstrap --config agent-version is ignored

Ci tests agent-version all the time. CI and Juju help use
    juju bootstrap aws aws-8 --agent-version 2.1.2

It is a bootstrap option, not a config. I see you used --config agent-version=2.1.2. Does this work when you follow pass the arg directly. model-config will show the agent-version, but I don't believe it can be changed to affect deployments. For example, anging the mode-config does not trigger an upgrade.

Curtis, thank you. I knew I had done this before, so it seemed crazy it wasn't working. So passing

--agent-version=

will set the bootstrap agent version and passing

--config agent-version=

will set the default model agent versions. Also I can't bootstrap with an version that doesn't match the minor version. So for example with the 2.1.2 client, I can't bootstrap with 2.0.x or 2.2.x.

$ juju bootstrap aws aws --agent-version='2.0.2'
error: requested agent version major.minor mismatch

$ juju bootstrap aws aws --agent-version='2.1-beta1'
Creating Juju controller "aws" on aws/us-east-1
Looking for packaged Juju agent version 2.1-beta1 for amd64

$ juju bootstrap aws--agent-version='2.2-alpha1'
error: requested agent version major.minor mismatch

I'll note bootstrap help text doesn't make this very clear.

I take that back. My original assertion is correct. Passing --config agent-version= is ignored. You can get the controller to bootstrap a specific agent version, however as noted.

I think that we need to clarify 'juju bootstrap' help message to clearly distinguish and call out subtleties between --agent-version and '--config agent-version'.

We can certainly improve the help text around this. But we do explicitly disallow bootstrapping to different minor versions from the client. (We had bugs in the past where the bootstrap process was different between versions, and that caused a 1.X version to try the 1.X bootstrap arguments against a 1.Y version agent, which failed.)

We could potentially step back from that, as we haven't been making serious changes there regularly, but most people feel more confident about strictly tying the client version to the bootstrapped agent version.

This report is now primary focused on improving help doc for bootstrap command.

I have also filed a docs issues for online manual to clarify what can be don/not done with a certain client: https://github.com/juju/docs/issues/1765

PR against develop (2.3): https://github.com/juju/juju/pull/7914