Previewing the Elastic docs in pull requests

In most Elastic repositories, when you open a pull request that affects the documentation, it calculates which books are affected and creates a PR check to build them.

If you need to re-run the check, add a comment like this:

@elasticmachine run docs build

or

@elasticmachine, run elasticsearch-ci/docs

To force all versions of the documentation to be rebuilt (not just the calculated subset), add a comment like this:

@elasticmachine, run elasticsearch-ci/docs rebuild