HDDS-9568. Add docusaurus build check in github actions

[adoroszlai]

What changes were proposed in this pull request?

Add smoketest that builds the website in CI.

https://issues.apache.org/jira/browse/HDDS-9568

How was this patch tested?

Introduced broken link, verified the same steps fail with:

Error: Unable to build website for locale en.
...
  [cause]: Error: Docusaurus found broken links!
...
  - On source page path = /docs/system-internals/features/ratis-streaming:
     -> linking to ./no-such-page (resolved as: /docs/system-internals/features/no-such-page)
...

CI:
https://github.com/adoroszlai/ozone-site/actions/runs/7740784527/job/21106463270

[errose28]

Thanks for working on this @adoroszlai

This implementation uses a mix of dependencies installed in the docker image and in the runner, which I think is a bit confusing (correct me if I'm reading this wrong):

docker build -t ozone-site:ci .

This installs all javascript dependencies into the image when building it.

docker run --rm -v $PWD:/ozone-site ozone-site:ci pnpm install

This mounts the current directory over the ozone-site directory in the image, covering the previously installed dependencies in /ozone-site/node_modules but using pnpm from the image. The dependencies here are installed into the runner directly so now we have two copies.

docker run --rm -v $PWD:/ozone-site ozone-site:ci pnpm build

This executes the build using pnpm from the image and dependencies from the runner. Dependencies installed into the image are not used.

I think we should use pnpm and the dependencies from the image to do the build, but leave the build output in the runner with the volume mount. We can do this with the existing compose file:

1. docker commpose build: Optional, since run will build the image anyways. Making this its own step might make for clearer CI messages though.
2. docker compose run site pnpm build: Builds the site using all dependencies in the image, but leaves the final build artifacts in the runner.
3. (Future PR) If this is a push to the HDDS-9225-website-v2 branch, re-use the pre-built artifacts in the commit step to the publishing branch.
4. (Future PR) Liveness check for the build: docker compose run --service-ports site pnpm serve followed by curl to check that the homepage is returned. Yunikorn has a similar check

[adoroszlai]

Thanks @errose28 for the explanation on how to use compose to build/run. I had a feeling that my steps are too complex.

[errose28]

Thanks for the updates @adoroszlai LGTM