Feature/tts 612 #109

	---
	name: Preview Button

	# yamllint disable-line rule:truthy
	on:
	pull_request:
	workflow_dispatch:

	permissions: read-all

	concurrency:
	group: ${{ github.ref }}-${{ github.workflow }}
	cancel-in-progress: true

	jobs:
	button:
	runs-on: ubuntu-22.04

	permissions: write-all

	steps:
	- name: Setup custom variables
	id: customvars
	run: \|
	( echo -n "BASE_URL="
	if [ -n "${{ vars.BASE_URL }}" ] ; then
	echo "${{ vars.BASE_URL }}"
	else
	echo "https://federalist-a2423046-fe43-4e75-a2ef-2651e5e123ca.sites.pages.cloud.gov/preview/gsa-tts/tts.gsa.gov/"
	fi

	echo -n "URL_PATH="
	if [ -n "${{ vars.URL_PATH }}" ] ; then
	echo "${{ vars.URL_PATH }}/"
	elif [ -n "${GITHUB_HEAD_REF:-}" ] ; then
	echo "${GITHUB_HEAD_REF}/"
	else
	echo "staging/"
	fi
	) >> "$GITHUB_OUTPUT"

	- name: Wait for site to render
	run: curl --retry-delay 10 --retry 18 --retry-all-errors -f -X HEAD -s -o /dev/null "${{ steps.customvars.outputs.BASE_URL }}${{ steps.customvars.outputs.URL_PATH }}"

	- name: Comment on pull request.
	uses: thollander/actions-comment-pull-request@fabd468d3a1a0b97feee5f6b9e499eab0dd903f6 # pin@v2.5.0
	with:
	GITHUB_TOKEN: ${{ secrets.PAT \|\| secrets.GITHUB_TOKEN \|\| github.token }}
	message: \|
	## Preview This Branch

	You may view the preview version of the site with the following URL:

	[${{ steps.customvars.outputs.BASE_URL }}${{ steps.customvars.outputs.URL_PATH }}](${{ steps.customvars.outputs.BASE_URL }}${{ steps.customvars.outputs.URL_PATH }})

	It may take a minute before changes in this Pull Request (PR) show up :stopwatch:
	comment_tag: button

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