Alibaba Cloud Service Mesh:Manage Istio resources with the Java SDK

Add the SDK dependency

Add the istio-client dependency to your Maven pom.xml:

<dependencies>
  <dependency>
    <groupId>io.fabric8</groupId>
    <artifactId>istio-client</artifactId>
    <version>6.0.0-RC1</version>
  </dependency>
</dependencies>

Connect to the ASM instance

The istio-client SDK reads your kubeconfig to connect to the ASM control plane. Copy the kubeconfig from the ASM console to your local machine:

1. Log on to the ASM console.

2. In the left-side navigation pane, choose Service Mesh > Mesh Management.

3. On the Mesh Management page, find your ASM instance and click its name, or click Manage in the Actions column.

4. In the left-side navigation pane, click Base Information. On the Basic Information page, click Connection.

5. In the Connection panel, copy the system kubeconfig file to $HOME/.kube/config on your machine.

By default, the SDK reads $HOME/.kube/config automatically. To use a different kubeconfig file, see Connect with a custom kubeconfig.

Prepare YAML configuration files

Save the virtualService.yaml and gateway.yaml files from Use ASM SDK to manage Istio resources in code to the Maven static resource folder (src/main/resources) in your project.

Load from a YAML file

The following example loads virtualService.yaml from the project resource folder and creates the VirtualService in the default namespace:

import java.io.FileReader;
import java.io.IOException;

import io.fabric8.istio.api.networking.v1beta1.VirtualService;
import io.fabric8.istio.client.DefaultIstioClient;
import io.fabric8.istio.client.IstioClient;
import io.fabric8.kubernetes.client.Config;
import io.fabric8.kubernetes.client.utils.IOHelpers;

public class VirtualServiceExample {
    public static void main(String[] args) {
        try {
            IstioClient istioClient = new DefaultIstioClient();
            final String NAMESPACE = "default"; // Target namespace for the resource
            VirtualService virtualService = istioClient.v1beta1().virtualServices().load(
                VirtualServiceExample.class.getResourceAsStream("/virtualService.yaml")
                ).get();
            istioClient.v1beta1().virtualServices().inNamespace(NAMESPACE).resource(virtualService).create();
            printAllVirtualServices(istioClient);
            istioClient.close();
        } catch (Exception e) {
            System.err.println("Failed to create VirtualService: " + e.getMessage());
            System.exit(1);
        }
    }

    // List all virtual services in the ASM instance
    static void printAllVirtualServices(IstioClient istioClient) {
        istioClient.v1beta1().virtualServices().list().getItems().forEach(System.out::println);
    }
}

Build with method chaining

Use VirtualServiceBuilder to construct the resource in code instead of loading YAML. The following example creates a Bookinfo VirtualService that routes traffic from the bookinfo-gateway to the productpage service on port 9080.

import io.fabric8.istio.api.networking.v1beta1.VirtualServiceBuilder;
import io.fabric8.istio.client.DefaultIstioClient;
import io.fabric8.istio.client.IstioClient;

public class VirtualServiceChainingExample {
    public static void main(String[] args) {
        try {
            IstioClient istioClient = new DefaultIstioClient();
            final String NAMESPACE = "default";
            istioClient.v1beta1().virtualServices().inNamespace(NAMESPACE).resource(
                new VirtualServiceBuilder()
                .withNewMetadata()
                .withName("bookinfo")
                .endMetadata()
                .withNewSpec()
                    .addToHosts("*")
                    .addToGateways("bookinfo-gateway")
                    .addNewHttp()
                        .addNewMatch().withNewUri().withNewStringMatchExactType("/productpage").endUri().endMatch()
                        .addNewMatch().withNewUri().withNewStringMatchPrefixType("/static").endUri().endMatch()
                        .addNewMatch().withNewUri().withNewStringMatchExactType("/login").endUri().endMatch()
                        .addNewMatch().withNewUri().withNewStringMatchExactType("/logout").endUri().endMatch()
                        .addNewMatch().withNewUri().withNewStringMatchPrefixType("/api/v1/products").endUri().endMatch()
                        .addNewRoute()
                            .withNewDestination()
                                .withHost("productpage")
                                .withNewPort()
                                    .withNumber(9080)
                                .endPort()
                            .endDestination()
                        .endRoute()
                    .endHttp()
                .endSpec()
                .build()
                ).create();
            printAllVirtualServices(istioClient);
            istioClient.close();
        } catch (Exception e) {
            System.err.println("Failed to create VirtualService: " + e.getMessage());
            System.exit(1);
        }
    }

    // List all virtual services in the ASM instance
    static void printAllVirtualServices(IstioClient istioClient) {
        istioClient.v1beta1().virtualServices().list().getItems().forEach(System.out::println);
    }
}