Add Netlify Build plugin to generate metadata normally provided by gi…

…thub-metadata gem

_config.yml

@@ -85,3 +85,4 @@ exclude:
   - webpack.config.js
   - README.md
   - LICENSE
+  - netlify

netlify.toml

@@ -1,3 +1,6 @@
 [build]
-  command = "jekyll build"
+  command = "jekyll build --config _config.yml,_config_override.yml"
   publish = "_site"
+
+[[plugins]]
+  package = "/netlify/plugins/netlify-jekyll-metadata"

netlify/plugins/netlify-jekyll-metadata/index.js

@@ -0,0 +1,12 @@
+import fs from 'node:fs'
+import url from 'node:url'
+
+export const onPreBuild = async function () {
+  const siteUrl = process.env.URL
+  const repoUrl = new URL(process.env.REPOSITORY_URL || '')
+  const repoNameWithOwner = repoUrl.pathname.replace(/^\/+/, '')
+
+  const fileName = '_config_override.yml'
+  const fileContents = `repository: ${repoNameWithOwner}\nurl: ${siteUrl}`
+  return fs.promises.writeFile(fileName, fileContents)
+}

netlify/plugins/netlify-jekyll-metadata/manifest.yml

@@ -0,0 +1 @@
+name: netlify-jekyll-metadata

netlify/plugins/netlify-jekyll-metadata/package.json

@@ -0,0 +1,6 @@
+{
+  "name": "netlify-jekyll-metadata",
+  "description": "Netlify Build Plugin to populate a Jekyll site with the metadata normally provided by the github-metadata gem",
+  "type": "module",
+  "exports": "./index.js"
+}