feat: add New Relic APM instrumentation to backend

Add Node.js New Relic agent with an on/off switch via NEW_RELIC_ENABLED
in .env. Uses a preload script (-r newrelic-preload.js) so the agent
loads before all other modules. Configured entirely through environment
variables — no newrelic.js config file needed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/Dockerfile

@@ -17,10 +17,16 @@ WORKDIR /app
 COPY package*.json ./
 RUN npm ci --omit=dev && npm cache clean --force
 
-# Copy compiled output from builder
+# Copy compiled output and New Relic preload from builder
 COPY --from=builder /app/dist ./dist
+COPY --from=builder /app/newrelic-preload.js ./newrelic-preload.js
+
+# New Relic agent — configured entirely via environment variables
+ENV NEW_RELIC_NO_CONFIG_FILE=true
+ENV NEW_RELIC_DISTRIBUTED_TRACING_ENABLED=true
+ENV NEW_RELIC_LOG=stdout
 
 EXPOSE 3000
 
-# Run the compiled JS directly — no ts-node, no watch, no devDeps
-CMD ["node", "dist/main"]
+# Preload the New Relic agent (activates only when NEW_RELIC_ENABLED=true)
+CMD ["node", "-r", "./newrelic-preload.js", "dist/main"]

backend/Dockerfile.dev

@@ -7,6 +7,11 @@ RUN npm install
 
 COPY . .
 
+# New Relic agent — configured entirely via environment variables
+ENV NEW_RELIC_NO_CONFIG_FILE=true
+ENV NEW_RELIC_DISTRIBUTED_TRACING_ENABLED=true
+ENV NEW_RELIC_LOG=stdout
+
 EXPOSE 3000
 
 CMD ["npm", "run", "start:dev"]

backend/newrelic-preload.js

@@ -0,0 +1,7 @@
+// Conditionally load the New Relic agent before any other modules.
+// Controlled by the NEW_RELIC_ENABLED environment variable (.env).
+'use strict';
+
+if (process.env.NEW_RELIC_ENABLED === 'true') {
+  require('newrelic');
+}

backend/package.json

@@ -8,7 +8,7 @@
     "start": "nest start",
     "start:dev": "nest start --watch",
     "start:debug": "nest start --debug --watch",
-    "start:prod": "node dist/main",
+    "start:prod": "node -r ./newrelic-preload.js dist/main",
     "lint": "eslint \"{src,apps,libs,test}/**/*.ts\"",
     "test": "jest",
     "test:watch": "jest --watch",
@@ -37,6 +37,7 @@
     "reflect-metadata": "^0.2.2",
     "rxjs": "^7.8.1",
     "typeorm": "^0.3.20",
+    "newrelic": "latest",
     "uuid": "^9.0.1"
   },
   "devDependencies": {