Java SDK Guide

Red Hat Virtualization 4.4

Using the Red Hat Virtualization Java SDK

Red Hat Virtualization Documentation Team

Red Hat Customer Content Services

Abstract

This guide describes how to install and work with version 4 of the Red Hat Virtualization Java software development kit.

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Chapter 1. Overview

Version 4 of the Java software development kit is a collection of classes that allows you to interact with the Red Hat Virtualization Manager in Java-based projects. By downloading these classes and adding them to your project, you can access a range of functionality for high-level automation of administrative tasks.

Note

Version 3 of the SDK is no longer supported. For more information, consult the RHV 4.3 version of this guide.

1.1. Prerequisites

To install the Java software development kit, you must have:

  • A system where Red Hat Enterprise Linux 7 is installed. Both the Server and Workstation variants are supported.
  • A subscription to Red Hat Virtualization entitlements.
Important

The software development kit is an interface for the Red Hat Virtualization REST API. Use the version of the software development kit that corresponds to the version of your Red Hat Virtualization environment. For example, if you are using Red Hat Virtualization 4.3, use V4 Java software development kit.

1.2. Installing the Java Software Development Kit

Install the Java software development kit and accompanying documentation.

Installing the Java Software Development Kit

  1. Enable the repositories:

    # subscription-manager repos \
        --enable=rhel-8-for-x86_64-baseos-rpms \
        --enable=rhel-8-for-x86_64-appstream-rpms \
        --enable=rhv-4.4-manager-for-rhel-8-x86_64-rpms\
        --enable=jb-eap-7.3-for-rhel-8-x86_64-rpms
  2. Enable the pki-deps module.

    # dnf module -y enable pki-deps
  3. Install the required packages for Java SDK V4:

    # dnf install java-ovirt-engine-sdk4

    The V4 Java software development kit and accompanying documentation are downloaded to the /usr/share/java/java-ovirt-engine-sdk4 directory and can be added to Java projects.

1.3. Dependencies

To use the Java software development kit in Java applications, you must add the following JAR files to the class path of those applications:

  • commons-beanutils.jar
  • commons-codec.jar
  • httpclient.jar
  • httpcore.jar
  • jakarta-commons-logging.jar
  • log4j.jar

The packages that provide these JAR files are installed as dependencies to the ovirt-engine-sdk-java package. By default, they are available in the /usr/share/java directory on Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7 systems.

1.4. Configuring SSL

The Red Hat Virtualization Manager Java SDK provides full support for HTTP over Secure Socket Layer (SSL) and the IETF Transport Layer Security (TLS) protocol using the Java Secure Socket Extension (JSSE). JSSE has been integrated into the Java 2 platform as of version 1.4 and works with the Java SDK out of the box. On earlier Java 2 versions, JSSE must be manually installed and configured.

1.4.1. Configuring SSL

The following procedure outlines how to configure SSL using the Java SDK.

Configuring SSL

  1. Download the certificate used by the Red Hat Virtualization Manager.

    Note

    By default, the location of the certificate used by the Red Hat Virtualization Manager is in /etc/pki/ovirt-engine/ca.pem.

  2. Create a truststore:

    $ keytool -import -alias "server.crt truststore" -file ca.crt -keystore server.truststore
  3. Specify the trustStoreFile and trustStorePassword arguments when constructing an instance of the Api or Connection object:

    myBuilder.trustStoreFile("/home/username/server.truststore");
    myBuilder.trustStorePassword("p@ssw0rd");
    Note

    If you do not specify the trustStoreFile option when creating a connection, the Java SDK attempts to use the default truststore specified by the system variable javax.net.ssl.trustStore. If this system variable does not specify a truststore, the Java SDK attempts to use a truststore specified in $JAVA_HOME/lib/security/jssecacerts or $JAVA_HOME/lib/security/cacerts.

1.4.2. Host Verification

By default, the identity of the host name in the certificate is verified when attempting to open a connection to the Red Hat Virtualization Manager. You can disable verification by passing the following argument when constructing an instance of the Connection class:

myBuilder.insecure(true);
Important

This method should not be used for production systems due to security reasons, unless it is a conscious decision and you are aware of the security implications of not verifying host identity.

Chapter 2. Using the Software Development Kit

This chapter outlines several examples of how to use the Java Software Development Kit. All examples in this chapter use version 3 of the software development kit unless otherwise noted.

2.1. Connecting to the Red Hat Virtualization Manager in Version 4

In V4 of the Java software development kit, the Connection class is the main class you use to connect to and manipulate objects in a Red Hat Virtualization environment. To declare an instance of this class, you must declare an instance of the ConnectionBuilder class, pass the required arguments to this instance using builder methods, then call the build method on the instance. The build method returns an instance of the Connection class that you can then assign to a variable and use to perform subsequent actions.

The following is an example of a simple Java SE program that creates a connection with a Red Hat Virtualization environment using version 4 of the software development kit:

Example 2.1. Connecting to the Red Hat Virtualization Manager

package rhevm;

import org.ovirt.engine.sdk4.Connection;
import org.ovirt.engine.sdk4.ConnectionBuilder;

public class rhevm {

    public static void main(String[] args) {

            ConnectionBuilder myBuilder = ConnectionBuilder.connection()

            .url("https://rhevm.example.com/ovirt-engine/api")
            .user("admin@internal")
            .password("p@ssw0rd")
            .trustStoreFile("/home/username/server.truststore")
            .trustStorePassword("p@ssw0rd");

        try (Connection conn = myBuilder.build()) {

            // Requests

        } catch (Exception e) {

            // Error handling

        }
    }
}

This example creates a connection using basic authentication, but other methods are also available. For a list of the key arguments that can be passed to instances of the ConnectionBuilder class, see Appendix A, ConnectionBuilder Methods.

2.2. Listing Entities

The following example outlines how to list entities in the Red Hat Virtualization Manager. In this example, the entities to be listed are virtual machines, which are listed using the getVMs() method of the Api class.

Listing Entities

  1. Declare a List of the type of entity to be listed and use the corresponding method to get the list of entities:

    List<VM> vms = api.getVMs().list();

2.3. Modifying the Attributes of Resources

The following example outlines how to modify the attributes of a resource. In this example, the attribute to be modified is the description of the virtual machine with the name 'test', which is changed to 'java_sdk'.

Modifying the Attributes of a Resource

  1. Declare an instance of the resource whose attributes are to be modified:

    VM vm = api.getVMs().get("test");
  2. Set the new value of the attribute:

    vm.setDescription("java_sdk");
  3. Update the virtual machine to apply the change:

    VM newVM = vm.update();

2.4. Getting a Resource

In the Java Software Development Kit, resources can be referred to via two attributes: name, and UUID. Both return an object with the specified attribute if that object exists.

To get a resource using the value of the name attribute:

VM vm = api.getVMs().get("test");

To get a resource using the value of the UUID attribute:

VM vm = api.getVMs().get(UUID.fromString("5a89a1d2-32be-33f7-a0d1-f8b5bc974ff6"));

2.5. Adding Resources

The following examples outline two ways to add resources to the Red Hat Virtualization Manager. In these examples, the resource to be added is a virtual machine.

Example 1

In this example, an instance of the VM class is declared to represent the new virtual machine to be added. Next, the attributes of that virtual machine set to the preferred values. Finally, the new virtual machine is added to the Manager.

org.ovirt.engine.sdk.entities.VM vmParams = new org.ovirt.engine.sdk.entities.VM();

vmParams.setName("myVm");
vmParams.setCluster(api.getClusters().get("myCluster"));
vmParams.setTemplate(api.getTemplates().get("myTemplate"));
...
VM vm = api.getVMs().add(vmParams);

Example 2

In this example, an instance of the VM class is declared in the same way as Example 1. However, rather than using the get method to reference existing objects in the Manager, each attribute is referenced by declaring an instance of that attribute. Finally, the new virtual machine is added to the Manager.

org.ovirt.engine.sdk.entities.VM vmParams = new org.ovirt.engine.sdk.entities.VM();

vmParams.setName("myVm");
org.ovirt.engine.sdk.entities.Cluster clusterParam = new Cluster();
clusterParam.setName("myCluster");
vmParams.setCluster(clusterParam);
org.ovirt.engine.sdk.entities.Template templateParam = new Template();
templateParam.setName("myTemplate");
vmParams.setTemplate(templateParam);
...
VM vm = api.getVMs().add(vmParams);

2.6. Performing Actions on Resources

The following example outlines how to perform actions on a resource. In this example, a virtual machine with the name 'test' is started.

Performing an Action on a Resource

  1. Declare an instance of the resource:

     VM vm = api.getVMs().get("test");
  2. Declare action parameters to send to the resource:

    Action actionParam = new Action();
    org.ovirt.engine.sdk.entities.VM vmParam = new org.ovirt.engine.sdk.entities.VM();
    actionParam.setVm(vmParam);
  3. Perform the action:

    Action res = vm.start(actionParam);

    Alternatively, you can perform the action as an inner method:

    Action res = vm.start(new Action()
    {
        {
            setVm(new org.ovirt.engine.sdk.entities.VM());
        }
    });

2.7. Listing Sub-Resources

The following example outlines how to list the sub-resources of a resource. In this example, the sub-resources of a virtual machine with the name 'test' are listed.

Listing Sub-Resources

  1. Declare an instance of the resource whose sub-resources are to be listed:

    VM vm = api.getVMs().get("test");
  2. List the sub-resources:

    List<VMDisk>; disks = vm.getDisks().list();

    === Getting Sub-Resources

The following example outlines how to reference the sub-resources of a resource. In this example, a disk with the name 'my disk' that belongs to a virtual machine with the name 'test' is referenced.

Getting the Sub-Resources of a Resource

  1. Declare an instance of the resource whose sub-resources are to be referenced:

    VM vm = api.getVMs().get("test");
  2. Declare an instance of the sub-resource to be referenced:

    VMDisk disk = vm.getDisks().get("my disk");

2.8. Adding Sub-Resources to a Resource

The following example outlines how to add sub-resources to a resource. In this example, a new disk with a size of '1073741824L', interface 'virtio' and format 'cow' are added to a virtual machine with the name 'test'.

Adding a Sub-Resource to a Resource

  1. Declare an instance of the resource to which sub-resources are to be added:

    VM vm = api.getVMs().get("test");
  2. Create parameters to define the attributes of the resource:

    Disk diskParam = new Disk();
    diskParam.setProvisionedSize(1073741824L);
    diskParam.setInterface("virtio");
    diskParam.setFormat("cow");
  3. Add the sub-resource:

    Disk disk = vm.getDisks().add(diskParam);

2.9. Modifying Sub-Resources

The following example outlines how to modify sub-resources. In this example, the name of a disk with the name 'test_Disk1' belonging to a virtual machine with the name 'test' is changed to 'test_Disk1_updated'.

Updating a Sub-Resource

  1. Declare an instance of the resource whose sub-resource is to be modified:

    VM vm = api.getVMs().get("test");
  2. Declare an instance of the sub-resource to be modified:

    VMDisk disk = vm.getDisks().get("test_Disk1");
  3. Set the new value of the attribute:

    disk.setAlias("test_Disk1_updated");
  4. Update the sub-resource:

    VMDisk updateDisk = disk.update();

2.10. Performing Actions on Sub-Resources

The following example outlines how to perform actions on sub-resources. In this example, a disk with the name 'test_Disk1' belonging to a virtual machine with the name 'test' is activated.

Performing an Action on a Sub-Resource

  1. Declare an instance of the resource containing the sub-resource on which the action is to be performed:

    VM vm = api.getVMs().get("test");
  2. Declare an instance of the sub-resource:

    VMDisk disk = vm.getDisks().get("test_Disk1");
  3. Declare action parameters to send to the sub-resource:

    Action actionParam = new Action();
  4. Perform the action:

    Action result = disk.activate(actionParam);

Appendix A. ConnectionBuilder Methods

The following table outlines the key methods available to the ConnectionBuilder class used in V4 of the Java software development kit.

Table A.1. ConnectionBuilder Methods

MethodArgument TypeDescription

user

String

The name of the user with which to connect to the Manager. You must specify both the user name and domain, such as admin@internal. This method must be used together with the password method.

password

String

The password of the user with which to connect to the Manager.

compress

Boolean

Specifies whether responses from the server where the Manager is hosted should be compressed. This option is disabled by default, so this method is only required to enable this option.

timeout

Integer

The timeout, in seconds, to wait for responses to requests. If a request takes longer than this value to respond, the request is cancelled, and an exception is thrown. This argument is optional.

ssoUrl

String

The base URL of the server where the Manager is hosted. For example, https://server.example.com/ovirt-engine/sso/oauth/token?\grant_type=password&scope=ovirt-app-api for password authentication.

ssoRevokeUrl

String

The base URL of the SSO revoke service. This option only needs to be specified when you use an external authentication service. By default, this URL is automatically calculated from the value of the url option so that SSO token revoke is performed using the SSO service that is part of the engine.

ssoTokenName

String

The token name in the JSON SSO response returned from the SSO server. By default, this value is access_token.

insecure

Boolean

Enables or disables verification of the host name in the SSL certificate presented by the server where the Manager is hosted. By default, the identity of host names is verified, and the connection is rejected if the host name is not correct, so this method is only required to disable this option.

trustStoreFile

String

Specifies the location of a file containing the CA certificate used to verify the certificate presented by the server where the Manager is hosted. This method must be used together with the trustStorePassword method.

trustStorePassword

String

The password used to access the keystore file specified in the trustStorePath method.