[ BAEL-5503 ] - Difference Between links and depends_on in Docker-Compose (#12503)

* updates pom-xml and adds Dockerfile to build a web-app image

* add depends-on vs links yml examples

docker-modules/docker-compose/Dockerfile

@@ -0,0 +1,4 @@
+FROM openjdk:11
+MAINTAINER baeldung.com
+COPY target/docker-compose-0.0.1-SNAPSHOT.jar app.jar
+ENTRYPOINT ["java","-jar","/app.jar"]

docker-modules/docker-compose/depends-on_vs_links/docker-compose-depends-on.yml

@@ -0,0 +1,14 @@
+services:
+  db:
+    image: postgres:latest
+    environment:
+      - POSTGRES_USER=postgres
+      - POSTGRES_PASSWORD=postgres
+    ports:
+      - 5432:5432
+  web-app:
+    image: web-app:latest
+    ports:
+      - 8080:8080
+    depends_on:
+      - db

docker-modules/docker-compose/depends-on_vs_links/docker-compose-links.yml

@@ -0,0 +1,14 @@
+services:
+  db:
+    image: postgres:latest
+    environment:
+      - POSTGRES_USER=postgres
+      - POSTGRES_PASSWORD=postgres
+    ports:
+      - 5432:5432
+  web-app:
+    image: web-app:latest
+    ports:
+      - 8080:8080
+    links:
+      - db

docker-modules/docker-compose/depends-on_vs_links/docker-compose-network.yml

@@ -0,0 +1,36 @@
+services:
+  db:
+    image: postgres:latest
+    restart: always
+    environment:
+      - POSTGRES_USER=postgres
+      - POSTGRES_PASSWORD=postgres
+    ports:
+      - 5432:5432
+    volumes:
+      - db:/var/lib/postgresql/data
+    networks:
+      - mynet
+
+  web-app:
+    image: web-app:latest
+    depends_on:
+      - db
+    networks:
+      - mynet
+    ports:
+      - 8080:8080
+    environment:
+      DB_HOST: db
+      DB_PORT: 5432
+      DB_USER: postgres
+      DB_PASSWORD: postgres
+      DB_NAME: postgres
+
+networks:
+  mynet:
+    driver: bridge
+
+volumes:
+  db:
+    driver: local

docker-modules/docker-compose/pom.xml

@@ -34,6 +34,16 @@
             <plugin>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-maven-plugin</artifactId>
+                <configuration>
+                    <mainClass>com.baeldung.docker.app.DockAppApplication</mainClass>
+                </configuration>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                    </execution>
+                </executions>
             </plugin>
         </plugins>
     </build>