aula-01: Docker Compose com restart policy

App Node.js que trava após MAX_REQUESTS para demonstrar
como o Docker Compose lida com containers que falham.

aula-01/.env

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+MAX_REQUESTS=3

aula-01/app.js

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+const http = require("http");
+
+const MAX_REQUESTS = Number(process.env.MAX_REQUESTS || 3);
+
+let requestCount = 0;
+
+console.log("MAX_REQUESTS =", MAX_REQUESTS);
+
+const server = http.createServer((req, res) => {
+  if (req.url === "/health") {
+    if (requestCount > MAX_REQUESTS) {
+      // app travado, mas processo vivo
+      return;
+    }
+
+    res.writeHead(200);
+    res.end(`ok`);
+    return;
+  }
+
+  requestCount++;
+  console.log("request", requestCount);
+
+  if (requestCount > MAX_REQUESTS) {
+    console.log(`🔥 App travado após ${MAX_REQUESTS} requests`);
+    return;
+  }
+
+  res.writeHead(200);
+  res.end(`Req -> ${requestCount}/${MAX_REQUESTS}`);
+});
+
+server.listen(3000, () => {
+  console.log("App rodando na porta 3000");
+});
+

aula-01/docker-compose.yml

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+services:
+  node-app:
+    image: node:24-alpine
+    container_name: node-bugado
+    working_dir: /app
+    volumes:
+      - ./app.js:/app/app.js
+    command: node app.js
+    ports:
+      - "3000:3000"
+    restart: always