Chapter 4 Extending the asadmin Utility

The asadmin utility is a command-line tool for configuring and administering Enterprise Server. Extending the asadmin utility enables you to provide administrative interfaces for an add-on component that are consistent with the interfaces of other Enterprise Server components. A user can run asadmin commands either from a command prompt or from a script. For more information about the asadmin utility, see the asadmin(1M) man page.

The following topics are addressed here:

• About the Administrative Command Infrastructure of Enterprise Server

• Adding an asadmin Command

• Adding Parameters to an asadmin Command

• Adding Message Text Strings to an asadmin Command

• Enabling an asadmin Command to Run

• Setting the Context of an asadmin Command

• Changing the Brand in the Enterprise Server CLI

• Examples of Extending the asadmin Utility

About the Administrative Command Infrastructure of Enterprise Server

To enable multiple containers to be independently packaged and loaded, the administrative command infrastructure of Enterprise Server provides the following features:

• Location independence. Administration commands can be loaded from any add-on component that is known to Enterprise Server.

• Extensibility. Administrative commands that are available to Enterprise Server are discovered on demand and not obtained from a preset list of commands.

• Support for the HK2 architecture. Commands can use injection to express their dependencies, and extraction to provide results to a user. For more information, see Chapter 2, Writing HK2 Components.

Adding an asadmin Command

An asadmin command identifies the operation or task that a user is to perform. Adding an asadmin command enables the user to perform these tasks and operations through the asadmin utility.

The following topics are addressed here:

• Representing an asadmin Command as a Java Class

• Specifying the Name of an asadmin Command

• Ensuring That an AdminCommand Implementation Is Stateless

• Example of Adding an asadmin Command

Representing an asadmin Command as a Java Class

Each asadmin command that you are adding must be represented as a Java class. To represent an asadmin command as a Java class, write a Java class that implements the org.glassfish.api.admin.AdminCommand interface. Write one class for each command that you are adding. Do not represent multiple asadmin commands in a single class.

Annotate the declaration of your implementations of the AdminCommand interface with the org.jvnet.hk2.annotations.Service annotation. The @Service annotation ensures that the following requirements for your implementations are met:

• The implementations are eligible for resource injection and resource extraction.

• The implementations are location independent, provided that the component that contains them is made known to the Enterprise Server runtime.

  For information about how to make a component known to the Enterprise Server runtime, see Integrating an Add-On Component With Enterprise Server.

Specifying the Name of an asadmin Command

To specify the name of the command, set the name element of the @Service annotation to the name.

Command names are case-sensitive.

Commands that are supplied in Enterprise Server distributions typically create, delete, and list objects of a particular type. For consistency with the names of commands that are supplied in Enterprise Server distributions, follow these conventions when specifying the name of a command:

• For commands that create an object of a particular type, use the name create-object.

• For commands that delete an object of a particular type, use the name delete-object.

• For commands that list all objects of a particular type, use the name list-objects.

For example, Enterprise Server provides the following commands for creating, deleting, and listing HTTP listeners:

• create-http-listener

• delete-http-listener

• list-http-listeners

You must also ensure that the name of your command is unique. To obtain a complete list of the names of all asadmin commands that are installed, use the list-commands(1) command. For a complete list of asadmin commands that are supplied in Enterprise Server distributions, see Sun GlassFish Enterprise Server v3 Prelude Reference Manual.

Ensuring That an AdminCommand Implementation Is Stateless

To enable multiple clients to run a command simultaneously, ensure that the implementation of the AdminCommand interface for the command is stateless. To ensure that the implementation of the AdminCommand interface is stateless, annotate the declaration of your implementation with the org.jvnet.hk2.annotations.Scoped annotation. In the @Scoped annotation, set the scope as follows:

• To instantiate the command for each lookup, set the scope to PerLookup.class.

• To instantiate the command only once for each session, set the scope to Singleton.

Example of Adding an asadmin Command

Example 4–1 Adding an asadmin Command

This example shows the declaration of the class CreateMycontainer that represents an asadmin command that is named create-mycontainer. The command is instantiated for each lookup.

package com.example.mycontainer;

import org.glassfish.api.admin.AdminCommand;
...
import org.jvnet.hk2.annotations.Service;
...
import org.jvnet.hk2.annotations.Scoped;
import org.jvnet.hk2.component.PerLookup;

/**
 * Sample command
 */
@Service(name="create-mycontainer")
@Scoped(PerLookup.class)
public Class CreateMycontainer implements AdminCommand {
…
}

Adding Parameters to an asadmin Command

The parameters of an asadmin command are the options and operands of the command.

• Options control how the asadmin utility performs a command.

• Operands are the objects on which a command acts. For example, the operand of the start-domain(1) command is the domain that is to be started.

The following topics are addressed here:

• Representing a Parameter of an asadmin Command

• Identifying a Parameter of an asadmin Command

• Specifying Whether a Parameter Is an Option or an Operand

• Specifying the Name of an Option

• Specifying the Acceptable Values of a Parameter

• Specifying the Default Value of a Parameter

• Specifying Whether a Parameter Is Required or Optional

• Example of Adding Parameters to an asadmin Command

Representing a Parameter of an asadmin Command

Represent each parameter of a command in your implementation as a field or as the property of a JavaBeans^TM specification setter method. Use the property of a setter method for the following reasons:

• To provide data encapsulation for the parameter

• To add code for validating the parameter before the property is set

Identifying a Parameter of an asadmin Command

Identifying a parameter of an asadmin command enables Enterprise Server to perform the following operations at runtime on the parameter:

• Validation. The Enterprise Server determines whether all required parameters are specified and returns an error if any required parameter is omitted.

• Injection. Before the command runs, the Enterprise Server injects each parameter into the required field or method before the command is run.

• Usage message generation. The Enterprise Server uses reflection to obtain the list of parameters for a command and to generate the usage message from this list.

• Localized string display. If the command supports internationalization and if localized strings are available, the Enterprise Server can automatically obtain the localized strings for a command and display them to the user.

To identify a parameter of a command, annotate the declaration of the item that is associated with the parameter with the org.glassfish.api.Param annotation. This item is either the field or setter method that is associated with the parameter.

To specify the properties of the parameter, use the elements of the @Param annotation as explained in the sections that follow.

Specifying Whether a Parameter Is an Option or an Operand

Whether a parameter is an option or an operand determines how a user must specify the parameter when running the command:

• If the parameter is an option, the user must specify the option with the parameter name.

• If the parameter is an operand, the user may omit the parameter name.

To specify whether a parameter is an option or an operand, set the primary element of the @Param annotation as follows:

• If the parameter is an option, set the primary element to false. This value is the default.

• If the parameter is an operand, set the primary element to true.

Specifying the Name of an Option

The name of an option is the name that a user must type on the command line to specify the option when running the command.

The name of each option that you add in your implementation of an asadmin command can have a long form and a short form. When running the command, the user specifies the long form and the short form as follows:

• The short form of an option name has a single dash (-) followed by a single character.

• The long form of an option name has two dashes (--) followed by an option word.

For example, the short form and the long form of the name of the option for specifying terse output are as follows:

• Short form: -m

• Long form: --monitor

Option names are case-sensitive.

Specifying the Long Form of an Option Name

To specify the long form of an option name, set the name element of the @Param annotation to a string that specifies the name. If you do not set this element, the default name depends on how you represent the option.

• If you represent the option as a field, the default name is the field name.

• If you represent the option as the property of a JavaBeans specification setter method, the default name is the property name from the setter method name. For example, if the setter method setPassword is associated with an option, the property name and the option name are both password.

Specifying the Short Form of an Option Name

To specify the short form of an option name, set the shortName element of the @Param annotation to a single character that specifies the short form of the parameter. The user can specify this character instead of the full parameter name, for example -m instead of --monitor. If you do not set this element, the option has no short form.

Specifying the Acceptable Values of a Parameter

When a user runs the command, the Enterprise Server validates option arguments and operands against the acceptable values that you specify in your implementation.

To specify the acceptable values of a parameter, set the acceptableValues element of the @Param annotation to a string that contains a comma-separated list of acceptable values. If you do not set this element, any string of characters is acceptable.

Specifying the Default Value of a Parameter

The default value of a parameter is the value that is applied if a user omits the parameter when running the command.

To specify the default value of a parameter, set the defaultValue element of the @Param annotation to a string that contains the default value. If you do not set this element, the parameter has no default value.

Specifying Whether a Parameter Is Required or Optional

Whether a parameter is required or optional determines how a command responds if a user omits the parameter when running the command:

• If the parameter is required, the command returns an error.

• If the parameter is optional, the command runs successfully.

To specify whether a parameter is optional or required, set the optional element of the @Param annotation as follows:

• If the parameter is required, set the optional element to false. This value is the default.

• If the parameter is optional, set the optional element to true.

Example of Adding Parameters to an asadmin Command

Example 4–2 Adding Parameters to an asadmin Command

This example shows the code for adding parameters to an asadmin command with the properties as shown in the table.

...
import org.glassfish.api.Param;
...
{
…
    @Param
    String originator;
    
    @Param(name="description", optional=true)
    …
    String mycontainerDescription
    
    @Param (acceptableValues="true,false", defaultValue="false", optional=true)
    String enabled
    
    @Param(primary=true)
    String containername;
…
}

Adding Message Text Strings to an asadmin Command

A message text string provides useful information to the user about an asadmin command or a parameter.

To provide internationalization support for the text string of a command or parameter, annotate the declaration of the command or parameter with the org.glassfish.api.I18n annotation. The @I18n annotation identifies the resource from the resource bundle that is associated with your implementation.

To add message text strings to an asadmin command, create a plain text file that is named LocalStrings.properties to contain the strings. Define each string on a separate line of the file as follows:

key=string

key

A key that maps the string to a command or a parameter. The format to use for key depends on the target to which the key applies and whether the target is annotated with the @I18n annotation. See the following table.

Target	Format
Command or parameter with the @I18n annotation	command-name.command.resource-name
Command without the @I18n annotation	command-name.command
Parameter without the @I18n annotation	command-name.command.param-name

The replaceable parts of these formats are as follows:

command-name

The name of the command.

resource-name

The name of the resource that is specified in the@I18n annotation.

param-name

The name of the parameter.

string

A string without quotes that contains the text of the message.

To display the message strings to users, you must provide code in your implementation of the execute method to display the text. For more information about implementing the execute method, see Enabling an asadmin Command to Run.

Example 4–3 Adding Message Strings to an asadmin Command

This example shows the code for adding message strings to the create-mycontainer command as follows:

• The create-mycontainer command is associated with the message Creates a custom container. No internationalization support is provided for this message.

• The --originator parameter is associated with the message The originator of the container. No internationalization support is provided for this message.

• The --description parameter is associated with the message that is contained in the resource mydesc, for which internationalization is provided. This resource contains the message text A description of the container.

• The --enabled parameter is associated with the message Whether the container is enabled or disabled. No internationalization support is provided for this message.

• The --containername parameter is associated with the message The container name. No internationalization support is provided for this message.

The addition of the parameters originator, description, enabled and containername to the command is shown in Example 4–2.

package com.example.mycontainer;

import org.glassfish.api.admin.AdminCommand;
...
import org.glassfish.api.I18n;
import org.glassfish.api.Param;
import org.jvnet.hk2.annotations.Service;
...
import org.jvnet.hk2.annotations.Scoped;
import org.jvnet.hk2.component.PerLookup;

/**
 * Sample command
 */
@Service(name="create-mycontainer")
@Scoped(PerLookup.class)
public Class CreateMycontainer implements AdminCommand {

    …

    @Param
    String originator;

    @Param(name="description", optional=true)
    @I18n("mydesc")
    String mycontainerDescription
   
    @Param (acceptableValues="true,false", defaultValue="false", optional=true)
    String enabled
    
    @Param(primary=true)
    String containername;
 …

}

The following message text strings are defined in the file LocalStrings.properties for use by the command:

create-mycontainer.command=Creates a custom container
create-mycontainer.command.originator=The originator of the container 
create-mycontainer.command.mydesc=A description of the container
create-mycontainer.command.enabled=Whether the container is enabled or disabled
create-mycontainer.command.containername=The container name

Enabling an asadmin Command to Run

To enable an asadmin command to run, implement the execute method in your implementation of the AdminCommand interface. The declaration of the execute method in your implementation must be as follows.

    public void execute(AdminCommandContext context);

Pass each parameter of the command as a property to your implementation of the execute method. Set the key of the property to the parameter name and set the value of the property to the parameter's value.

Setting the Context of an asadmin Command

The org.glassfish.api.admin.AdminCommandContext class provides the following services to an asadmin command:

• Access to the parameters of the command

• Logging

• Reporting

To set the context of an asadmin command, pass an AdminCommandContext object to the execute method of your implementation.

Changing the Brand in the Enterprise Server CLI

The brand in the Enterprise Server command-line interface (CLI) consists of the product name and release information that are displayed in the following locations:

• In the string that the version(1) command displays

• In each entry in the server.log file

If you are incorporating Enterprise Server into a new product with an external vendor's own brand name, change the brand in the Enterprise Server CLI.

To change the brand in the Enterprise Server CLI, create an OSGi fragment bundle that contains a plain text file that is named src/main/resources/BrandingVersion.properties.

In the BrandingVersion.properties file, define the following keyword-value pairs:

product_name=product-name
abbrev_product_name=abbrev-product-name
major_version=major-version
minor_version=minor-version
build_id=build-id
version_prefix=version-prefix
version_suffix=version-suffix

Define each keyword-value pair on a separate line of the file. Each value is a text string without quotes.

The meaning of each keyword-value pair is as follows:

product_name=product-name

Specifies the full product name without any release information, for example, Sun GlassFish Enterprise Server.

abbrev_product_name=abbrev-product-name

Specifies an abbreviated form of the product name without any release information, for example, Sun GlassFish.

major_version=major-version

Returns the product major version, for example, 3

minor_version=minor-version

Specifies the product minor version, for example, 0.

build_id=build-id

Specifies the build version, for example, build 17.

version_prefix=version-prefix

Specifies a prefix for the product version, for example, v.

version_suffix=version-suffix

Specifies a suffix for the product version, for example, Prelude.

Example 4–4 BrandingVersion.properties File for Changing the Brand in the Enterprise Server CLI

This example shows the content of the BrandingVersion.properties for defining the product name and release information of Sun GlassFish Enterprise Server v3.0 Prelude, build 17. The abbreviated product name is sun-glassfish.

product_name=Sun GlassFish Enterprise Server
abbrev_product_name=sun-glassfish
major_version=3
minor_version=0
build_id=build 17
version_prefix=v
version_suffix=Prelude

Examples of Extending the asadmin Utility

Example 4–5 Example asadmin Command With Empty execute Method

This example shows a class that represents the asadmin command create-mycontainer.

The usage statement for this command is as follows:

asadmin create-mycontainer --originator any-character-string
[--description any-character-string]
[--enabled {true|false}]  any-character-string

This command uses injection to specify that a running domain is required.

package com.example.mycontainer;

import org.glassfish.api.admin.AdminCommand;
import org.glassfish.api.admin.AdminCommandContext;
import org.glassfish.api.I18n;
import org.glassfish.api.Param;
import org.jvnet.hk2.annotations.Service;
import org.jvnet.hk2.annotations.Inject;
import org.jvnet.hk2.annotations.Scoped;
import org.jvnet.hk2.component.PerLookup;

/**
 * Sample command
 */
@Service(name="create-mycontainer")
@Scoped(PerLookup.class)
public Class CreateMycontainer implements AdminCommand {

    @Inject
    Domain domain;

    @Param
    String originator;

    @Param(name="description", optional=true)
    @I18n("mydesc")
    String mycontainerDescription

    @Param (acceptableValues="true,false", defaultValue="false", optional=true)
    String enabled
    
    @Param(primary=true)
    String containername;

    /**
     * Executes the command with the command parameters passed as Properties 
     * where the keys are the paramter names and the values the parameter values
     * @param context information 
     */
    public void execute(AdminCommandContext context) {
        // domain and originator are not null
        // mycontainerDescription can be null.
    }
}

The following message text strings are defined in the file LocalStrings.properties for use by the command:

create-mycontainer.command=Creates a custom container
create-mycontainer.command.originator=The originator of the container 
create-mycontainer.command.mydesc=A description of the container
create-mycontainer.command.enabled=Whether the container is enabled or disabled
create-mycontainer.command.containername=The container name

Example 4–6 Fully Functional asadmin Command

This example shows a class that represents the asadmin command list-runtime-environment. The command determines the operating system or runtime information for Enterprise Server

The usage statement for this command is as follows:

asadmin list-runtime-environment{runtime|os}

package com.example.env.cli;

import org.glassfish.api.admin.AdminCommand;
import org.glassfish.api.admin.AdminCommandContext;
import org.glassfish.api.ActionReport;
import org.glassfish.api.I18n;
import org.glassfish.api.ActionReport.ExitCode;
import org.glassfish.api.Param;
import org.jvnet.hk2.annotations.Service;
import org.jvnet.hk2.annotations.Inject;
import org.jvnet.hk2.annotations.Scoped;
import org.jvnet.hk2.component.PerLookup;

import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.lang.management.RuntimeMXBean;

/**
 * Demos asadmin CLI extension
 *
  */
@Service(name="list-runtime-environment")
@Scoped(PerLookup.class)
public class ListRuntimeEnvironmentCommand implements AdminCommand {
    
    // this value can be either runtime or os for our demo
    @Param(primary=true)
    String inParam;
    
    public void execute(AdminCommandContext context) {

        ActionReport report = context.getActionReport();
        report.setActionExitCode(ExitCode.SUCCESS);

        // If the inParam is 'os' then this command returns operating system info
        // and if the inParam is 'runtime' then it returns runtime info.
        // Both of the above are based on mxbeans.

        if ("os".equals(inParam)) {
            OperatingSystemMXBean osmb = ManagementFactory.getOperatingSystemMXBean();
            report.setMessage("Your machine operating system name = " + osmb.getName());
        } else if ("runtime".equals(inParam)) {
            RuntimeMXBean rtmb = ManagementFactory.getRuntimeMXBean();
            report.setMessage("Your JVM name = " + rtmb.getVmName());
        } else {
            report.setActionExitCode(ExitCode.FAILURE);
            report.setMessage("operand should be either 'os' or 'runtime'");
        }

    }
}