Alibaba Cloud Service Mesh:Use the SDK for Java to manage Istio resources

Preparations

Install dependencies

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

Configure a connection

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 the ASM instance that you want to configure. Click the name of the ASM instance or click Manage in the Actions column.

4. On the details page of the ASM instance, click Base Information in the left-side navigation pane. On the Basic Information page, click Connection.

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

   Note

   By default, the system kubeconfig file is used to configure a connection. For more information about how to use a specific kubeconfig file, see the Create an Istio gateway section of this topic.

Generate configuration files

Create a virtual service

If you use istio-client to create Istio resources in Java, you can use YAML files or method chaining. To create a virtual service, you can use one of the following methods:

Method 1: Use a YAML file to create a virtual service

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 ) {
        IstioClient istioClient = new DefaultIstioClient();
        final String NAMESPACE = "default"; // The namespace in which you want to create 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();
    }


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

Method 2: Use method chaining to create a virtual service

You can use the method chaining capability of istio-client to create a virtual service by running code.

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) {
        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();
    }

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

Create an Istio gateway

After you use a specific kubeconfig file to configure a connection, you can create an Istio gateway in the default namespace by using the gateway.yaml file. In this example, a YAML file is used to create an Istio gateway. For more information about how to use method chaining, see the Method 2: Use method chaining to create a virtual service section of this topic.

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

import io.fabric8.istio.api.networking.v1beta1.Gateway;
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 GateWayExample {
    public static void main(String[] args) throws IOException {
        // Read the specified kubeconfig file to configure a connection. 
        String kubeconfigContents = null;
        FileReader reader = new FileReader("{path to kube config file}"); // Replace the content of {} with the path of the kubeconfig file that you want to use. 
        kubeconfigContents = IOHelpers.readFully(reader);
        Config config = Config.fromKubeconfig(null, kubeconfigContents, null);

        IstioClient istioClient = new DefaultIstioClient(config);
        final String NAMESPACE = "default"; // The namespace in which you want to create the resource. 
        Gateway gateway = istioClient.v1beta1().gateways().load(
            GateWayExample.class.getResourceAsStream("/gateway.yaml")
        ).get();
        istioClient.v1beta1().gateways().inNamespace(NAMESPACE).resource(gateway).create();
        printAllGateways(istioClient);
        istioClient.close();
    }

    // Display all gateways in the ASM instance. 
    static void printAllGateways(IstioClient istioClient) {
        istioClient.v1beta1().gateways().list().getItems().forEach(System.out::println);
    }
}