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/app.js

@@ -0,0 +1,36 @@
+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");
+});
+