using chartpress with pre-commit

[rokroskar]

I've started using chartpress --reset with the pre-commit package and it works very nicely to prevent accidental commits of modified chart values. It would be great to have the .pre-commit.hooks.yaml definition as a part of chartpress so one could simply include it like any other pre-commit hook. The user of chartpress would then have a .pre-commit.config.yaml in their repo's base directory with something like:

repos:
-   repo: https://github.com/jupyterhub/chartpress
    rev: master
    hooks:
    - id: chartpress

If then you try to commit a change to the chartpress-managed values you get something like:

git commit -am 'commiting something'
black................................................(no files to check)Skipped
Flake8...............................................(no files to check)Skipped
chartpress reset.........................................................Failed
hookid: chartpress

If you want to include something like this I'll happily contribute a PR.

[minrk]

chartpress is often pretty expensive to run, which can be quite frustrating for pre-commit hooks, which need to be very quick to avoid causing friction. But it would at least be interesting to see an example

[rokroskar]

Sure, my suggestion here is to only run it with the reset flag to avoid committing rendered charts - that should be very cheap to run.

[rokroskar]

@minrk here's a full example of my .pre-commit-config.yaml file:

repos:
-   repo: local
    hooks:
    - id: chartpress
      name: chartpress reset
      files: helm-chart/*
      description: Run `chartpress --reset` to clean up helm charts before committing.
      entry: pipenv run chartpress --reset
      language: system
      pass_filenames: false

The result is something like this:

# rendering the chart
$ chartpress

# trying to commit
git commit -am 'bla'
chartpress reset.........................................................Failed
hookid: chartpress

Files were modified by this hook. Additional output:

$> git log -n 1 --pretty=format:%h -- . . jupyterhub singleuser
$> git log -n 1 --pretty=format:%h -- . chartpress.yaml
$> git log -n 1 --pretty=format:%h -- jupyterhub jupyterhub chartpress.yaml
$> git log -n 1 --pretty=format:%h -- git-clone git-clone chartpress.yaml
Updating helm-chart/renku-notebooks/values.yaml: image: {'repository': 'renku/renku-notebooks', 'tag': 'latest'}
Updating helm-chart/renku-notebooks/values.yaml: jupyterhub.hub.image: {'repository': 'renku/jupyterhub-k8s', 'tag': 'latest'}
Updating helm-chart/renku-notebooks/values.yaml: git_clone.image: {'repository': 'renku/git-clone', 'tag': 'latest'}

[consideRatio]

chartpress --reset is or at least should have very high performance. It will probably be about as easy to setup a local hook as it would be to declare one in this repo though right, since it is just a one liner. From the example you provided, it seems like it makes a lot of sense to use a local hook, as there are some local chart configuration matters as well.

@rokroskar perhaps we could have this local hook example documented in the readme? What do you think?

repos:
-   repo: local
    hooks:
    - id: chartpress
      name: chartpress reset
      files: helm-chart/*
      description: Run `chartpress --reset` to clean up helm charts before committing.
      entry: pipenv run chartpress --reset
      language: system
      pass_filenames: false

[rokroskar]

@consideRatio yes I think it could be useful for some - has definitely saved me from having to rebase/force-push my commits all the time :)

But you might want to omit the pipenv parts, since those are presumably user-specific.

[consideRatio]

I explored pre-commit a bit further and were happy to learn it really isn't disruptive at all, it works on a lines of code level and will not modify anything except whats conflicting etc.

I added the following .pre-commit-config.yaml entry to the jupyterhub/zero-to-jupyterhub-k8s helm chart in jupyterhub/zero-to-jupyterhub-k8s#1970

A problem for people may be that chartpress can only be run from the folder where chartpress.yaml is located, but I assume pre-commit will invoke it from the git repo root folder which may not be the same, so the entry will possibly need to include a directory change first.

I've no experience with chartpress hooks definitions etc, but if we can do something like...

1. search for a chartpress.yaml file in the repo
2. execute chartpress from there
3. override default files trigger to /Chart.yaml|/values.yaml changes (or whatever the syntax will be).

Then I'd be up for defining a .pre-commit-hook.yaml as part of this repo and not only provide an example. But, in the linked PR, it wouldn't just work for the jupyterhub/binderhub repo I think for example, because of the difference of having chartpress.yaml defined in non-root folder

[rokroskar]

Thanks for following up on this @consideRatio - I've been using this setup for some time and it works well. A question though:

A problem for people may be that chartpress can only be run from the folder where chartpress.yaml is located

I've always wished for a -f flag with chartpress 😄 - afaik all the paths are defined relative to the chartpress.yaml file so in principle there is no hard-coded dependency on cwd that couldn't be overcome.

[manics]

Does #118 Allow chartpress to be run from a different folder cover the last feature request? Is there anything else required here or can we close this?

[consideRatio]

Let's close this and not maintain a chartpress pre-commit hook that is very easy and plausible to define locally to do whats wanted anyhow.