feat: added ECS fargate-load-balanced-service Java example (#160)

* Initial commit of Java fargate-load-balanced-service

* Removed unused code and updated ECSFargateLoadBalancedStack

* Linked Java version of fargate-load-balanced-service to the README.md

* Updated expected CloudFormation for the JUnit test

* Removed unused imports

* Added some comments and did some code cleanup

README.md

@@ -64,6 +64,7 @@ $ cdk destroy
 
 | Example | Description |
 |---------|-------------|
+| [fargate-load-balanced-service](https://github.com/aws-samples/aws-cdk-examples/tree/master/java/ecs/fargate-load-balanced-service/) | Starting a container fronted by a load balancer on Fargate |
 | [hello-world](https://github.com/aws-samples/aws-cdk-examples/tree/master/java/hello-world/) | A demo application that uses the CDK in Java |
 | [lambda-cron](https://github.com/aws-samples/aws-cdk-examples/tree/master/java/lambda-cron/) | Running a Lambda on a schedule |
 | [resource-overrides](https://github.com/aws-samples/aws-cdk-examples/tree/master/java/resource-overrides/) | Use of the resource overrides (aka ["escape hatch"](https://docs.aws.amazon.com/cdk/latest/guide/cfn_layer.html)) mechanism. |

java/ecs/fargate-load-balanced-service/.gitignore

@@ -0,0 +1,14 @@
+.classpath.txt
+target
+.classpath
+.project
+.idea
+.settings
+.vscode
+*.iml
+cdk.context.json
+
+# CDK asset staging directory
+.cdk.staging
+cdk.out
+

java/ecs/fargate-load-balanced-service/README.md

@@ -0,0 +1,22 @@
+
+Welcome to your CDK Java project!
+
+It is a Maven-based project, so you can open this directory with any Maven-compatible Java IDE,
+and you should be able to build and run tests from your IDE.
+
+You should explore the contents of this template. It demonstrates a CDK app with two instances of
+a stack (`HelloStack`) which also uses a user-defined construct (`HelloConstruct`).
+
+The `cdk.json` file tells the CDK Toolkit how to execute your app. This example relies on maven
+to do that.
+
+# Useful commands
+
+ * `mvn package`     compile and run tests
+ * `cdk ls`          list all stacks in the app
+ * `cdk synth`       emits the synthesized CloudFormation template
+ * `cdk deploy`      deploy this stack to your default AWS account/region
+ * `cdk diff`        compare deployed stack with current state
+ * `cdk docs`        open CDK documentation
+
+Enjoy!

java/ecs/fargate-load-balanced-service/cdk.json

@@ -0,0 +1,3 @@
+{
+  "app": "mvn -q exec:java"
+}

java/ecs/fargate-load-balanced-service/pom.xml

@@ -0,0 +1,64 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+         xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.amazonaws.cdk</groupId>
+    <artifactId>fargate-load-balanced-service</artifactId>
+    <version>0.1</version>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.7.0</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+                <version>1.6.0</version>
+                <configuration>
+                    <mainClass>com.amazonaws.cdk.examples.ECSFargateLoadBalancedApp</mainClass>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <dependencies>
+        <!-- AWS Cloud Development Kit -->
+        <dependency>
+            <groupId>software.amazon.awscdk</groupId>
+            <artifactId>core</artifactId>
+            <version>1.16.0.DEVPREVIEW</version>
+        </dependency>
+
+        <!-- Respective AWS Construct Libraries -->
+        <dependency>
+            <groupId>software.amazon.awscdk</groupId>
+            <artifactId>ecs</artifactId>
+            <version>1.16.0.DEVPREVIEW</version>
+        </dependency>
+        <dependency>
+            <groupId>software.amazon.awscdk</groupId>
+            <artifactId>ecs-patterns</artifactId>
+            <version>1.16.0.DEVPREVIEW</version>
+        </dependency>
+
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

java/ecs/fargate-load-balanced-service/src/main/java/com/amazonaws/cdk/examples/ECSFargateLoadBalancedApp.java

@@ -0,0 +1,14 @@
+package com.amazonaws.cdk.examples;
+
+import software.amazon.awscdk.core.App;
+
+public class ECSFargateLoadBalancedApp {
+    public static void main(final String argv[]) {
+        App app = new App();
+
+        new ECSFargateLoadBalancedStack(app, "fargate-load-balanced-service");
+
+        // required until https://github.com/aws/jsii/issues/456 is resolved
+        app.synth();
+    }
+}

java/ecs/fargate-load-balanced-service/src/main/java/com/amazonaws/cdk/examples/ECSFargateLoadBalancedStack.java

@@ -0,0 +1,39 @@
+package com.amazonaws.cdk.examples;
+
+import software.amazon.awscdk.core.*;
+import software.amazon.awscdk.services.ec2.Vpc;
+import software.amazon.awscdk.services.ec2.VpcProps;
+import software.amazon.awscdk.services.ecs.Cluster;
+import software.amazon.awscdk.services.ecs.ClusterProps;
+import software.amazon.awscdk.services.ecs.ContainerImage;
+import software.amazon.awscdk.services.ecs.patterns.NetworkLoadBalancedFargateService;
+import software.amazon.awscdk.services.ecs.patterns.NetworkLoadBalancedFargateServiceProps;
+import software.amazon.awscdk.services.ecs.patterns.NetworkLoadBalancedTaskImageOptions;
+
+public class ECSFargateLoadBalancedStack extends Stack {
+
+    public ECSFargateLoadBalancedStack(final Construct parent, final String id) {
+        this(parent, id, null);
+    }
+
+    public ECSFargateLoadBalancedStack(final Construct parent, final String id, final StackProps props) {
+        super(parent, id, props);
+
+        // Create VPC with a AZ limit of two.
+        Vpc vpc = new Vpc(this, "MyVpc", VpcProps.builder().maxAzs(2).build());
+
+        // Create the ECS Service
+        Cluster cluster = new Cluster(this, "Ec2Cluster", ClusterProps.builder().vpc(vpc).build());
+
+        // Use the ECS Network Load Balanced Fargate Service construct to create a ECS service
+        NetworkLoadBalancedFargateService fargateService = new NetworkLoadBalancedFargateService(
+                this,
+                "FargateService",
+                NetworkLoadBalancedFargateServiceProps.builder()
+                        .cluster(cluster)
+                        .taskImageOptions(NetworkLoadBalancedTaskImageOptions.builder()
+                                .image(ContainerImage.fromRegistry("amazon/amazon-ecs-sample"))
+                                .build())
+                        .build());
+    }
+}

java/ecs/fargate-load-balanced-service/src/test/java/com/amazonaws/cdk/examples/ECSFargateLoadBalancedStackTest.java

@@ -0,0 +1,28 @@
+package com.amazonaws.cdk.examples;
+
+import software.amazon.awscdk.core.App;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.SerializationFeature;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import static junit.framework.TestCase.assertEquals;
+
+public class ECSFargateLoadBalancedStackTest {
+    private final static ObjectMapper JSON =
+        new ObjectMapper().configure(SerializationFeature.INDENT_OUTPUT, true);
+
+    @Test
+    public void testStack() throws IOException {
+        App app = new App();
+        ECSFargateLoadBalancedStack stack = new ECSFargateLoadBalancedStack(app, "test");
+
+        // synthesize the stack to a CloudFormation template and compare against
+        // a checked-in JSON file.
+        JsonNode actual = JSON.valueToTree(app.synth().getStackArtifact(stack.getArtifactId()).getTemplate());
+        JsonNode expected = JSON.readTree(getClass().getResource("expected.cfn.json"));
+        assertEquals(expected, actual);
+    }
+}