Add lychee link checker GitHub Action (#237)

Inspired by kubecost/docs#704
Fixes #134

Signed-off-by: Matt Ray <[email protected]>

.github/workflows/checks-links.yaml

@@ -0,0 +1,34 @@
+name: Check Links
+
+on:
+  repository_dispatch:
+  workflow_dispatch:
+  pull_request:
+    branches:
+      - main
+  schedule:
+    - cron: "0 0 * * *"
+
+jobs:
+  linkChecker:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Link Checker
+        id: lychee
+        uses: lycheeverse/lychee-action@v1
+        env:
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
+        with:
+          fail: true
+          debug: false
+          args: --verbose --no-progress --base . -E './**/*.md' './**/*.mdx'
+
+      - name: Create Issue From File
+        if: env.lychee_exit_code != 0
+        uses: peter-evans/create-issue-from-file@v4
+        with:
+          title: Link Checker Report
+          content-filepath: ./lychee/out.md
+          labels: report, automated issue

README.md

@@ -1,3 +1,5 @@
+[![Check Links](https://github.com/org/repo/actions/workflows/links.yml/badge.svg)](https://github.com/org/repo/actions/workflows/links.yml)
+
 # OpenCost Website
 
 This repository hosts the [OpenCost website](https://opencost.io), documentation, and blog.