step 2

app/Dockerfile

@@ -0,0 +1,9 @@
+FROM gradle:7.4.0-jdk17
+
+WORKDIR /app
+
+COPY /app .
+
+RUN gradle installDist
+
+CMD ./build/install/app/bin/app

app/build.gradle

@@ -17,6 +17,8 @@ dependencies {
     testImplementation 'org.junit.jupiter:junit-jupiter-api:5.8.1'
     testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.8.1'
     implementation 'info.picocli:picocli:4.7.1'
+    implementation 'io.javalin:javalin:4.6.1'
+    implementation 'org.slf4j:slf4j-simple:1.7.36'
 }
 
 test {

app/src/main/java/hexlet/code/App.java

@@ -1,8 +1,17 @@
 package hexlet.code;
 
+import io.javalin.Javalin;
+import io.javalin.core.JavalinConfig;
+
 public class App {
     public static void main(String[] args) {
-        System.out.println("Hello world!");
+        Javalin app = getApp();
+        app.start(8080);
+    }
+    public static Javalin getApp() {
+        Javalin app = Javalin.create(JavalinConfig::enableDevLogging)
+                .get("/", ctx -> ctx.result("Hello World"));
+        return app;
     }
     public static String forTest() {
         return "Im worked";