Automatic update of the extension list

[szkiba]

What?

Automatic update of the k6 extension list in the docs/sources/next/extensions/explore.md
file in case of changes based on the https://registry.k6.io/registry.json extension registry.

The change is pushed to the extension-registry-changed branch and a pull request is opened
(or updated) about the change.

The extension list is updated by the scripts/extension-registry-changed script.
The script is started by the extension-registry-changed workflow defined in the
.github/workflows/extension-registry-changed.yml workflow file.
The extension-registry-changed workflow is triggered by the grafana/k6-extension-registry
repository when the registry changes using a repository_dispatch event of type extension-registry-changed.

It is not a problem if the registry changes several times before merging the pull request,
the pull request will be updated. The "extension-registry-changed" branch can be deleted
after merging the pull request, it will be created again if necessary.

Checklist

• I have used a meaningful title for the PR.
• I have described the changes I've made in the "What?" section above.
• I have performed a self-review of my changes.
• I have run the npm start command locally and verified that the changes look good.

Related PR(s)/Issue(s)

#1640

Closes #1640

[szkiba]

In this temporary repo, you can see what kind of pull request the automation generates:
https://github.com/grafana/k6-docs-extension-registry-changed/pulls

[szkiba]

I see that "npm run build" does not run because of src/templates/docs/explore-extensions.js. Am I right that since explore.md is not generated but edited manually, this file can be deleted?

[szkiba]

As a quick and dirty workaround, I kept a dummy extension in the extensions.json file for the build to run. Is that acceptable?

[jdbaldry]

Thanks for putting this together. I've added some comments for the Bash script.

[jdbaldry]

I generally use mktemp because it respects the TMPDIR environment variable

[szkiba]

right, I'll fix it

[szkiba]

fixed

[szkiba]

@jdbaldry, Thanks for the review, it's actually been quite a while since I last wrote scripts more seriously :)
I have made the suggested changes.
I would appreciate it if you would formally approve the PR again before I merge it.

[jdbaldry]

One more thing that came to mind as I was thinking through the workflow execution is the failure modes of the script.

I generally put set -euf -o pipefail at the start of the script to end execution for any failing command including those with piped output. The thought being that if any individual step fails, the rest of the script operates with false assumptions and then can only further mangle the final output.

It's not a huge concern because we always have the PR to review and reject if it has unexpected changes so up to you if you want to incorporate.

[szkiba]

If you don't mind, I'll merge it, then modify it if necessary.