update

Jenkinsfile

@@ -2,11 +2,52 @@ pipeline {
   agent any
 
   stages {
-        stage('Build') {
+    stage('Checkout') {
       steps {
-                echo 'Building...'
+        checkout scm
-                sh 'docker build -t my-python-app .'
       }
     }
+
+    stage('Build Image') {
+      steps {
+        echo 'Building image...'
+        // --pull ensures base layer is fresh; tag includes BUILD_NUMBER to avoid cache clashes
+        sh 'docker build --pull -t my-python-app:${BUILD_NUMBER} .'
+      }
+    }
+
+    stage('Run Container') {
+      steps {
+        echo 'Running container...'
+        // --rm cleans up; this will print "Hello, World!" to the console
+        sh 'docker run --rm --name my-python-app-${BUILD_NUMBER} my-python-app:${BUILD_NUMBER}'
+      }
+    }
+
+    stage('(Optional) Verify Output') {
+      steps {
+        script {
+          // Re-run capturing output to assert expected behavior (example)
+          def out = sh(
+            script: 'docker run --rm my-python-app:${BUILD_NUMBER}',
+            returnStdout: true
+          ).trim()
+          if (out != 'Hello, World!') {
+            error "Unexpected output: '${out}'"
+          }
+        }
+      }
+    }
+  }
+
+  post {
+    always {
+      // Best-effort cleanup of any leftover container/image for this build tag
+      sh '''
+        docker rm -f my-python-app-${BUILD_NUMBER} 2>/dev/null || true
+        docker image rm my-python-app:${BUILD_NUMBER} 2>/dev/null || true
+      '''
+    }
   }
 }
+``