aula-02: Kubernetes com liveness probe

Deployment com liveness probe para detectar quando a app
trava e reiniciar o container automaticamente.

aula-02/configmap.yaml

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+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: app-config
+data:
+  MAX_REQUESTS: "3"
+
+  app.js: |
+    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) {
+          console.log('❌ O health check falhou');
+          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-02/deployment.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: node-bugado
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: node-bugado
+  template:
+    metadata:
+      labels:
+        app: node-bugado
+    spec:
+      terminationGracePeriodSeconds: 5
+      containers:
+        - name: app
+          image: node:24-alpine
+          command: ["node", "/app/app.js"]
+          env:
+            - name: MAX_REQUESTS
+              valueFrom:
+                configMapKeyRef:
+                  name: app-config
+                  key: MAX_REQUESTS
+          ports:
+            - containerPort: 3000
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: 3000
+            initialDelaySeconds: 5 # Espera para começar a testar
+            periodSeconds: 2 # A cada 5 segs faz o teste novamente
+            failureThreshold: 2 # Vezes seguidas antes de ser considerado morto
+          volumeMounts:
+            - name: app-volume
+              mountPath: /app
+      volumes:
+        - name: app-volume
+          configMap:
+            name: app-config

aula-02/service.yaml

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+apiVersion: v1
+kind: Service
+metadata:
+  name: node-bugado
+spec:
+  type: LoadBalancer
+  selector:
+    app: node-bugado
+  ports:
+    - port: 3000
+      targetPort: 3000
+      protocol: TCP