[v17] Hostname validation: document invalid hostnames #64557

	# This changelog ensures that PR bodies include a `changelog: <changelog entry>` section,
	# or a `no-changelog` label set. If they do not, then a comment will be added to the PR
	# asking the developer to add one of the two.
	name: Validate changelog entry
	on:
	pull_request:
	types:
	- edited
	- labeled
	- opened
	- ready_for_review
	- reopened
	- synchronize
	- unlabeled

	permissions:
	pull-requests: write

	concurrency:
	cancel-in-progress: true
	# This value is arbitrary as long as it includes the pull request number
	group: 'limit to running one instance at a time for the pull request ${{ github.event.pull_request.number }}'

	jobs:
	validate-changelog:
	name: Validate the changelog entry
	if: ${{ !github.event.pull_request.draft }}
	runs-on: ubuntu-latest
	steps:
	# Checkout main branch of shared-workflow repository.
	- name: Checkout shared-workflow
	uses: actions/checkout@v4
	with:
	repository: gravitational/shared-workflows
	path: .github/shared-workflows
	ref: main
	- name: Installing Go
	uses: actions/setup-go@v5
	with:
	go-version: 'stable'
	- name: Validate the changelog entry
	run: cd .github/shared-workflows/bot && go run main.go -workflow=changelog -token="${{ secrets.GITHUB_TOKEN }}" -reviewers="${{ secrets.reviewers }}"

Provide feedback