Default bundle scale is "0"

[Benjamin Allot]

Hello,

Trying a new k8s charm with juju 2.8.1 and a bundle looking like this

bundle: kubernetes
applications:
  mm-pd-bot:
    charm: {{ charm_dir }}/mm-pd-bot
    options:
      image_path: stg-is.docker-registry.canonical.com/mm-pd-bot:latest
      mm_pd_bot_cfg: include-file://{{ local_dir }}/bot.cfg
      tls_secret_name: mm-pd-bot-staging-canonical-com-tls
      # Those parameters are k8s specific
      juju-external-hostname: mm-pd-bot.staging.canonical.com

The result was a deployed application but no pod.
It took me some time to understand that I needed "scale: 1".
The only reference I could find was https://juju.is/docs/charm-bundles about the Kubernetes bundle and it's mentioned nowhere that "scale: 1" MUST be used.

That's pretty confusing because usually, you want at least one pod for your application.
I would rather have a default to "scale: 1" and the possibility to set "scale: 0" if really needed.

What do you think ?

[Paul Collins (pjdc)]

This sounds similar to the existing bug for max_units defaulting to 0, LP:1595330.

[Ian Booth (wallyworld)]

Yes, it is the same issue as that older linked bug 1595330.

"scale" was implemented to have the same behaviour as "num_units", and "num_units" is treated as an alias for "scale". The issue with changing the default is as highlighted in the linked bug, so there's not necessarily a quick fix.

[Tytus Kurek (tkurek)]

I don't think the importance "Medium" is relevant here. The default scale of 0 is not intuitive, confusing and forces people to use bundles which are more complex than artifacts used by other open source projects.

[Pen Gale (pengale)]

@tkurek do you have the bits to change the importance of this one? Changing the importance isn't necessarily going to change that the fix is an involved one, and we have only so much time available. But you're the Product Manager, and I think that it's reasonable to expect you to be able to change the priority for a bug when you believe that we've got it wrong.

[Pen Gale (pengale)]

This is planned roadmap work for the 3.0.0 release. Changed tagging and milestone to reflect that.

[Juan M. Tirado (tiradojm)]

This looks already fixed. Please reopen it if needed.

[Launchpad Janitor (janitor)]

[Expired for Canonical Juju because there has been no activity for 60 days.]