Add the github-discord-notifier code

infra/workers/README.md

@@ -7,7 +7,7 @@ Each worker is a self contained directory with its each `package.json`.
 
 ## Deploying
 
-* Switch to a worker directory, e.g. `cd health-check`.
+* Switch to a worker directory, e.g. `cd github-discord-notifier`.
 
 * Install dependencies (if needed) with `yarn`
 
@@ -21,8 +21,8 @@ wrangler tail`.
 
 ## Creating a new worker
 
-Copy paste an existing one. Unironically this is a good option because the
-Cloudflare template has a lot of unnecessary noise, but if really do want to
+Copy paste an existing one. Unironically this is a good option because
+Cloudflare's template has a lot of unnecessary noise, but if really do want to
 create one from scratch, use `npm create cloudflare@latest`.
 
 To import an existing worker from the Cloudflare dashboard, use

infra/workers/github-discord-notifier/package.json

@@ -0,0 +1,9 @@
+{
+    "name": "github-discord-notifier",
+    "private": true,
+    "devDependencies": {
+        "@cloudflare/workers-types": "^4.20240314.0",
+        "typescript": "^5",
+        "wrangler": "^3"
+    }
+}

infra/workers/github-discord-notifier/src/index.ts

@@ -0,0 +1,49 @@
+/**
+ * Forward notifications from GitHub to Discord.
+ *
+ * This worker receives webhooks from GitHub, filters out the ones we don't
+ * need, and forwards them to a Discord webhook.
+ *
+ * [Note: GitHub specific Discord Webhooks]
+ *
+ * By appending `/github` to the end of the webhook URL, we can get Discord to
+ * automatically parse the payload sent by GitHub.
+ * https://discord.com/developers/docs/resources/webhook#execute-githubcompatible-webhook
+ *
+ * Note that this doesn't work for all events. And sadly, the events it doesn't
+ * work for get silently ignored (Discord responds with a 204).
+ * https://github.com/discord/discord-api-docs/issues/6203#issuecomment-1608151265
+ */
+export default {
+    async fetch(request: Request, env: Env) {
+        return handleRequest(request, env.DISCORD_WEBHOOK_URL);
+    },
+} satisfies ExportedHandler<Env>;
+
+interface Env {
+    DISCORD_WEBHOOK_URL: string;
+}
+
+const handleRequest = async (request: Request, targetURL: string) => {
+    const requestBody = await request.text();
+    let sender = JSON.parse(requestBody)["sender"]["login"];
+    if (sender === "cloudflare-pages[bot]" || sender === "CLAassistant") {
+        // Ignore pings from CF bot
+        return new Response(null, { status: 200 });
+    }
+
+    const response = await fetch(targetURL, {
+        method: request.method,
+        headers: request.headers,
+        body: requestBody,
+    });
+
+    const responseBody = await response.text();
+    const newResponse = new Response(responseBody, {
+        status: response.status,
+        statusText: response.statusText,
+        headers: response.headers,
+    });
+
+    return newResponse;
+};

infra/workers/github-discord-notifier/tsconfig.json

@@ -0,0 +1 @@
+{ "extends": "../tsconfig.base.json", "include": ["src/**/*.ts"] }

infra/workers/github-discord-notifier/wrangler.toml

@@ -0,0 +1,3 @@
+name = "github-discord-notifier"
+main = "src/index.ts"
+compatibility_date = "2024-03-14"