Backend: add support for analytics (log which host name responds)

enricoros · Dec 5, 2023 · 1b4a8da · 1b4a8da
1 parent 31684c2
commit 1b4a8da
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Showing 5 changed files with 42 additions and 9 deletions.
diff --git a/docs/environment-variables.md b/docs/environment-variables.md
@@ -9,10 +9,6 @@ which take place over _defaults_. This file is kept in sync with [`../src/server
 
 Environment variables can be set by creating a `.env` file in the root directory of the project.
 
-> For Docker deployment, ensure all necessary environment variables are set **both during build and run**.
-> If the Docker container is built without setting environment variables, the frontend UI will be unaware
-> of them, despite the backend being able to use them at runtime.
-
 The following is an example `.env` for copy-paste convenience:
 
 ```bash
@@ -45,6 +41,9 @@ GOOGLE_CLOUD_API_KEY=
 GOOGLE_CSE_ID=
 # Browse
 PUPPETEER_WSS_ENDPOINT=
+
+# Backend Analytics
+BACKEND_ANALYTICS=
 ```
 
 ## Variables Documentation
@@ -108,6 +107,8 @@ Enable the app to Talk, Draw, and Google things up.
 | `PRODIA_API_KEY`         | Prodia API Key - used with '/imagine ...'                                                                               |
 | **Browse**               |                                                                                                                         |
 | `PUPPETEER_WSS_ENDPOINT` | Puppeteer WebSocket endpoint - used for browsing, etc.                                                                  |
+| **Backend**              |                                                                                                                         | 
+| `BACKEND_ANALYTICS`      | Semicolon-separated list of analytics flags (see backend.analytics.ts). Flags: `domain` logs the responding domain.     |
 
 ---
 

diff --git a/src/modules/backend/backend.analytics.ts b/src/modules/backend/backend.analytics.ts
@@ -0,0 +1,23 @@
+import { track } from '@vercel/analytics/server';
+
+import { env } from '~/server/env.mjs';
+
+
+// all the backend analytics flags
+type BackendAnalyticsFlag =
+  | 'domain';   // logs which domain the initial (capabilities) request is sent to
+
+
+const checkAnalyticsFlag = (flag: BackendAnalyticsFlag): boolean =>
+  env.BACKEND_ANALYTICS?.includes(flag) || false;
+
+
+export function analyticsListCapabilities(backendHostName: string) {
+  if (checkAnalyticsFlag('domain')) {
+    // Note: fire-and-forget
+    void track('backend-domain', {
+      hostname: backendHostName,
+      vercel_url: process.env.VERCEL_URL || 'no-vercel',
+    });
+  }
+}
diff --git a/src/modules/backend/backend.router.ts b/src/modules/backend/backend.router.ts
@@ -1,6 +1,8 @@
 import { createTRPCRouter, publicProcedure } from '~/server/api/trpc.server';
 import { env } from '~/server/env.mjs';
 
+import { analyticsListCapabilities } from './backend.analytics';
+
 
 /**
  * This is the primary router for the backend. Mainly, this deals with letting
@@ -12,7 +14,8 @@ export const backendRouter = createTRPCRouter({
 
   /* List server-side capabilities (pre-configured by the deployer) */
   listCapabilities: publicProcedure
-    .query(async () => {
+    .query(async ({ ctx }) => {
+      analyticsListCapabilities(ctx.hostName);
       return {
         hasDB: !!env.POSTGRES_PRISMA_URL && !!env.POSTGRES_URL_NON_POOLING,
         hasBrowsing: !!env.PUPPETEER_WSS_ENDPOINT,

diff --git a/src/server/api/trpc.server.ts b/src/server/api/trpc.server.ts
@@ -19,10 +19,13 @@ import { ZodError } from 'zod';
  * These allow you to access things when processing a request, like the database, the session, etc.
  */
 
-export const createTRPCFetchContext = ({ /*req, resHeaders*/ }: { req: Request; resHeaders: Headers; }) => {
+export const createTRPCFetchContext = ({ req /*, resHeaders*/ }: { req: Request; resHeaders: Headers; }) => {
   // const user = { name: req.headers.get('username') ?? 'anonymous' };
   // return { req, resHeaders };
-  return {};
+  return {
+    // only used by Backend Analytics
+    hostName: req.headers?.get('host') ?? 'localhost',
+  };
 };
 
 

diff --git a/src/server/env.mjs b/src/server/env.mjs
@@ -4,7 +4,7 @@ import { z } from 'zod';
 export const env = createEnv({
   server: {
 
-    // Postgres, for optional storage via Prisma
+    // Backend Postgres, for optional storage via Prisma
     POSTGRES_PRISMA_URL: z.string().url().optional(),
     POSTGRES_URL_NON_POOLING: z.string().url().optional(),
 
@@ -44,7 +44,10 @@ export const env = createEnv({
 
     // Browsing Service
     PUPPETEER_WSS_ENDPOINT: z.string().url().optional(),
-
+
+    // Backend: Analytics flags (e.g. which hostname responds) for managed installs
+    BACKEND_ANALYTICS: z.string().optional().transform(list => (list || '').split(';').filter(flag => !!flag)),
+
   },
 
   onValidationError: error => {