feat: serve AsyncAPI JSON Schema definitions

README.md

@@ -65,6 +65,14 @@ npm run build
 
 Generated files of the website go to the `.next` folder.
 
+## JSON Schema definitions
+
+All AsyncAPI JSON Schema definition files are being served within the `/definitions/<file>` path. The content is being served from GH, in particular from https://github.com/asyncapi/spec-json-schemas/tree/master/schemas.
+This is possible thanks to the following:
+
+1. A [Netlify Rewrite rule](https://docs.netlify.com/routing/redirects/rewrites-proxies/) located in the [netlify.toml](netlify.toml) file, which acts as proxy for all requests to the `/definitions/<file>` path, serving the content from GH without having an HTTP redirect.
+2. A [Netlify Edge Function](https://docs.netlify.com/netlify-labs/experimental-features/edge-functions/) that modifies the `Content-Type` header of the rewrite response to become `application/schema+json`. This lets tooling, such as [Hyperjump](https://json-schema.hyperjump.io), to fetch the schemas directly from their URL.
+
 ## Project structure
 
 This repository has the following structure:
@@ -85,6 +93,8 @@ This repository has the following structure:
   ├── public                      # Data for site metadata and static blog such as images
   ├── scripts                     # Scripts used in the build and dev processes
   ├── next.config.js              # Next.js configuration file
+  ├── netlify                     # Code that runs on Netlify
+  │    ├── edge-functions         # Netlify Edge-Functions code
   ├── postcss.config.js           # PostCSS configuration file
   └── tailwind.config.js          # TailwindCSS configuration file
 ```

netlify.toml

@@ -7,4 +7,34 @@
   command = "npm run build && npm run export"
   functions = "netlify/functions"
   publish = "out"
-
+
+# Used by JSON Schema definitions fetched directly from AsyncAPI website
+[[redirects]]
+  from = "/definitions"
+  to = "https://github.com/asyncapi/spec-json-schemas/tree/master/schemas"
+  status = 200
+
+[[redirects]]
+  from = "/definitions/*"
+  to = "https://raw.githubusercontent.com/asyncapi/spec-json-schemas/master/schemas/:splat"
+  status = 200
+
+[[edge_functions]]
+function = "serve-definitions"
+path = "/definitions/*"
+
+# Used by JSON Schema definitions fetched from schemastore.org
+[[redirects]]
+  from = "/schema-store"
+  to = "https://github.com/asyncapi/spec-json-schemas/tree/master/schemas"
+  status = 200
+
+[[redirects]]
+  from = "/schema-store/*"
+  to = "https://raw.githubusercontent.com/asyncapi/spec-json-schemas/master/schemas/:splat"
+  status = 200
+
+[[edge_functions]]
+function = "serve-definitions"
+path = "/schema-store/*"
+

netlify/edge-functions/serve-definitions.ts

@@ -0,0 +1,97 @@
+import type { Context } from "netlify:edge";
+
+const GITHUB_TOKEN = Deno.env.get("GITHUB_TOKEN");
+const NR_ACCOUNT = Deno.env.get("NR_ACCOUNT");
+const NR_API_KEY = Deno.env.get("NR_API_KEY");
+
+export default async (request: Request, context: Context) => {
+  // Deleting Origin header, which is involved in the cache policy, so requests can hit GH cache.
+  // Reason: raw.githubusercontent.com responses include vary: Authorization,Accept-Encoding,Origin
+  request.headers.delete("origin");
+
+  // Setting GH Token to increase GH rate limit to 5,000 req/h.
+  request.headers.set("Authorization", "token " + GITHUB_TOKEN);
+
+  // Fetching the definition file
+  const response = await context.next();
+
+  const isRequestingAFile = request.url.charAt(request.url.length - 1) !== "/";
+  if (isRequestingAFile) {
+    if (response.ok) {
+      // Setting proper Content-Type header for JSON Schema files.
+      // This lets tooling fetch the schemas directly from their URL.
+      response.headers.set("Content-Type", "application/schema+json");
+
+      // Sending metrics to NR.
+      const event = {
+        "eventType": "AsyncAPIJSONSchemaDefinitionDownload",
+      };
+
+      await sendEventToNR(request, context, event);
+    } else {
+      // Notifying NR of the error.
+      const event = {
+        "eventType": "AsyncAPIJSONSchemaDefinitionDownloadError",
+        "responseStatus": response.status,
+        "responseStatusText": response.statusText,
+      };
+
+      await sendEventToNR(request, context, event);
+    }
+  } 
+
+  return response;
+};
+
+interface TimeoutRequestInit extends RequestInit {
+  timeout: number;
+}
+
+async function doFetch(resource: string, options: TimeoutRequestInit): Promise<Response> {
+  const { timeout = 5000 } = options;
+
+  const controller = new AbortController();
+  const timeoutId = setTimeout(() => controller.abort(), timeout);
+  const response = await fetch(resource, {...options, signal: controller.signal});
+  clearTimeout(timeoutId);
+  return response;
+}
+
+interface NREvent {
+  eventType: string;
+  url?: string;
+  source?: string;
+  file?: string;
+}
+
+async function sendEventToNR(request: Request, context: Context, event: NREvent) {
+  const splitPath = new URL(request.url).pathname.split("/");
+  if (event.source === "" || event.source === undefined) {
+    event.source = splitPath[1];
+    event.file = splitPath[2];
+  }
+
+  event.url = request.url;
+
+  try {
+    const rawResponse = await doFetch(`https://insights-collector.eu01.nr-data.net/v1/accounts/${NR_ACCOUNT}/events`, {
+      timeout: 2000, // Success in 2 seconds, cancel if not. User's request is more important than collecting metrics.
+      method: 'POST',
+      headers: {
+        'Api-Key': NR_API_KEY || "",
+        'Content-Type': 'application/json'
+      },
+      body: JSON.stringify(event)
+    });
+
+    if (rawResponse.status !== 200) {
+      context.log(`Unexpected response status code when sending metrics: ${rawResponse.status} ${rawResponse.statusText}`);
+    }
+  } catch (e) {
+    if (e instanceof DOMException) {
+      context.log(`Timeout during sending metrics: ${e}`);
+    } else {
+      context.log(`Unexpected error sending metrics: ${e}`);
+    }
+  }
+}