diff --git a/.DS_Store b/.DS_Store
index f2af216..6f081f6 100644
Binary files a/.DS_Store and b/.DS_Store differ
diff --git a/.gitignore b/.gitignore
index cc5ffdb..a88d11a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,5 @@ CuestionarioKubernetes.docx
 Videos de Clase
 Hojas de Asistencia
 Clase 3/Clase 3.pptx
-Clase 3/Ejercicio/nginx-app
\ No newline at end of file
+Clase 3/Ejercicio/nginx-app
+Clase 4/Clase 4.pptx
\ No newline at end of file
diff --git a/Clase 1/.DS_Store b/Clase 1/.DS_Store
index ef7dd80..352fcff 100644
Binary files a/Clase 1/.DS_Store and b/Clase 1/.DS_Store differ
diff --git a/Clase 1/Ejercicio/.DS_Store b/Clase 1/Ejercicio/.DS_Store
index 29d4177..6a28dc5 100644
Binary files a/Clase 1/Ejercicio/.DS_Store and b/Clase 1/Ejercicio/.DS_Store differ
diff --git a/Clase 2/.DS_Store b/Clase 2/.DS_Store
index c1db7d3..c62c457 100644
Binary files a/Clase 2/.DS_Store and b/Clase 2/.DS_Store differ
diff --git a/Clase 2/Ejercicio/.DS_Store b/Clase 2/Ejercicio/.DS_Store
index 9570fcf..5426c66 100644
Binary files a/Clase 2/Ejercicio/.DS_Store and b/Clase 2/Ejercicio/.DS_Store differ
diff --git a/Clase 4/.DS_Store b/Clase 4/.DS_Store
new file mode 100644
index 0000000..ea07b92
Binary files /dev/null and b/Clase 4/.DS_Store differ
diff --git a/Clase 4/Ejercicio/node-show-text-app/configmap.yaml b/Clase 4/Ejercicio/node-show-text-app/configmap.yaml
new file mode 100644
index 0000000..e3ea512
--- /dev/null
+++ b/Clase 4/Ejercicio/node-show-text-app/configmap.yaml	
@@ -0,0 +1,42 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: node-app-configmap
+  namespace: node-app
+data:
+  # Mensaje personalizado
+  message: "Este es un mensaje personalizado."
+  # file-like keys
+  # Archivo de app (Código)
+  app.js: |
+    const express = require('express')
+    const app = express()
+    const port = process.env.PORT ? process.env.PORT : 80
+
+    app.get('/', (req, res) => {
+      res.send(process.env.MESSAGE ? process.env.MESSAGE : 'Hello World!')
+    })
+
+    app.get('/secret', (req, res) => {
+      res.send(process.env.SECRET ? process.env.SECRET : 'Hello Secret World!')
+    })
+
+
+    app.listen(port, () => {
+      console.log(`Example app listening on port ${port}`)
+    })
+  package.json: |
+    {
+      "name": "show-text-app",
+      "version": "1.0.0",
+      "description": "example app",
+      "main": "app.js",
+      "scripts": {
+        "test": "echo \"Error: no test specified\" && exit 1"
+      },
+      "author": "Alejandro Lembke Barrientos",
+      "license": "MIT",
+      "dependencies": {
+        "express": "^4.18.1"
+      }
+    }
\ No newline at end of file
diff --git a/Clase 4/Ejercicio/node-show-text-app/deployment.yaml b/Clase 4/Ejercicio/node-show-text-app/deployment.yaml
new file mode 100644
index 0000000..8791d6d
--- /dev/null
+++ b/Clase 4/Ejercicio/node-show-text-app/deployment.yaml	
@@ -0,0 +1,69 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: node-app
+  namespace: node-app
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: node-app
+  template:
+    metadata:
+        labels:
+          app: node-app
+    spec:
+      containers:
+        - name: node-app
+          image: ubuntu
+          command:
+            - "/bin/sh"
+            - "-c"
+            - "tail -f /dev/null"
+          env:
+          - name: PORT
+            value: "3000"
+          - name: SECRET
+            valueFrom:
+              secretKeyRef:
+                name: node-app-secret
+                key: secret
+          - name: MESSAGE
+            valueFrom:
+              configMapKeyRef:
+                name: node-app-configmap
+                key: message
+          resources:
+            limits:
+              memory: "128Mi"
+              cpu: "500m"
+          ports:
+            - containerPort: 3000
+          lifecycle:
+            postStart:
+              exec:
+                command:
+                  - "/bin/sh"
+                  - "-c"
+                  - "apt-get update"
+                  - "&&"
+                  - "apt-get install curl -y"
+                  - "&&"
+                  - "curl -sL https://deb.nodesource.com/setup_16.x -o nodesource_setup.sh"
+                  - "&&"
+                  - "bash nodesource_setup.sh"
+                  - "&&"
+                  - "apt install nodejs"
+                  - "&&"
+                  - "cd /app && npm install && node app.js"
+          volumeMounts:
+            - name: app-files
+              mountPath: /app/app.js
+              subPath: app.js
+            - name: app-files
+              mountPath: /app/package.json
+              subPath: package.json
+      volumes:
+      - name: app-files
+        configMap:
+          name: node-app-configmap
\ No newline at end of file
diff --git a/Clase 4/Ejercicio/node-show-text-app/namespace.yaml b/Clase 4/Ejercicio/node-show-text-app/namespace.yaml
new file mode 100644
index 0000000..4875e50
--- /dev/null
+++ b/Clase 4/Ejercicio/node-show-text-app/namespace.yaml	
@@ -0,0 +1,4 @@
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: node-app
\ No newline at end of file
diff --git a/Clase 4/Ejercicio/node-show-text-app/secret.yaml b/Clase 4/Ejercicio/node-show-text-app/secret.yaml
new file mode 100644
index 0000000..c16ae59
--- /dev/null
+++ b/Clase 4/Ejercicio/node-show-text-app/secret.yaml	
@@ -0,0 +1,8 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  name: node-app-secret
+  namespace: node-app
+type: Opaque
+data:
+  secret: RXN0ZSBlcyB1biB0ZXh0byBzZWNyZXRvLg==
diff --git a/Clase 4/Ejercicio/node-show-text-app/service.yaml b/Clase 4/Ejercicio/node-show-text-app/service.yaml
new file mode 100644
index 0000000..7a69df2
--- /dev/null
+++ b/Clase 4/Ejercicio/node-show-text-app/service.yaml	
@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: node-app-svc
+  namespace: node-app
+  labels:
+    app: node-app
+spec:
+  type: ClusterIP
+  selector:
+    app: node-app
+  ports:
+  - port: 80
+    targetPort: 3000
\ No newline at end of file