4. Writing Agent Plug-ins: Background

<plugin name="JMX"
        displayName="Generic JMX"
        package="org.rhq.plugins.jmx"
        description="Supports management of JMX MBean Servers via various remoting systems."
        ampsVersion="2.0"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns="urn:xmlns:rhq-plugin"
        xmlns:c="urn:xmlns:rhq-configuration">

   <server name="JMX Server" discovery="JMXDiscoveryComponent" class="JMXServerComponent"
           description="Generic JMX Server"
	   supportsManualAdd="true" createDeletePolicy="neither">

<plugin-configuration>
  <c:list-property name="Servers">
     <c:map-property name="OneServer">
        <c:simple-property name="host"/>
        <c:simple-property name="port">
           <c:integer-constraint 
              minimum="0"
              maximum="65535"/> 
        </c:simple-property>
        <c:simple-property name="protocol">
           <c:property-options>
              <c:option value="http" default="true"/>
              <c:option value="https"/>
           </c:property-options>
        </c:simple-property>
     </c:map-property>
  </c:list-property>
</plugin-configuration>

         <c:template name="JDK 5" description="Connect to JDK 5">
            <c:simple-property name="type" default="org.mc4j.ems.connection.support.metadata.J2SE5ConnectionTypeDescriptor"/>
            <c:simple-property name="connectorAddress" default="service:jmx:rmi:///jndi/rmi://localhost:8999/jmxrmi"/>
         </c:template>

/**
 * Discovery class
 */
public class testDiscovery implements ResourceDiscoveryComponent
,ManualAddFacet
{

    private final Log log = LogFactory.getLog(this.getClass());

      /**
       * Do the manual add of this one resource
       */
      public DiscoveredResourceDetails discoverResource(Configuration pluginConfiguration, ResourceDiscoveryContext context) throws InvalidPluginConfigurationException {

            // TODO implement this
            DiscoveredResourceDetails detail = null; // new DiscoveredResourceDetails(
//                context.getResourceType(), // ResourceType
//            );

            return detail;
      }
}

    public DiscoveredResourceDetails discoverResource(Configuration pluginConfig,
                                                      ResourceDiscoveryContext discoveryContext)
            throws InvalidPluginConfigurationException {
        // TODO: Connect to the remote JVM to verify the user-specified conn props are valid, and if connecting
        // fails, throw an exception.
        String resourceKey = pluginConfig.getSimpleValue(CONNECTOR_ADDRESS_CONFIG_PROPERTY, null);
        String connectionType = pluginConfig.getSimpleValue(CONNECTION_TYPE, null);
                            
        // TODO (ips, 09/04/09): We should connect to the remote JVM in order to obtain its version.
        String version = null;
                    
        DiscoveredResourceDetails resourceDetails = new DiscoveredResourceDetails(discoveryContext.getResourceType(),
                resourceKey, "Java VM", version, connectionType + " [" + resourceKey + "]", pluginConfig, null);
        return resourceDetails;
    }  

process|attribute|match=value,arg|attribute|match=value

jsmith     2035   0.0 -1.5   724712  30616  p7  S+    9:49PM   0:01.61 java  
 -Dprogram.name=run.sh -Xms128m -Xmx512m -Dsun.rmi.dgc.client.gcInterval=3600000
 -Dsun.rmi.dgc.server.gcInterval=3600000 -Djboss.platform.mbeanserver
 -Djava.endorsed.dirs=/devel/jboss-4.0.5.GA/lib/endorsed
 -classpath /devel/jboss-4.0.5.GA/bin/run.jar:/lib/tools.jar
 org.jboss.Main -c minimal

process|attribute|match=value,arg|attribute|match=value
   |       |       |____      |_    |____     |______
   |       |            |       |        |           |
   |       |            |       |        |           |
   |       |            |       |        |           |
   |       |            |       |        |           |
process|basename|match=^java.*,arg|org.jboss.Main|match=.*

process|attribute|match=value

process|pidfile|match=/etc/product/lock.pid

   List<ProcessScanResult< autoDiscoveryResults = 
      context.getAutoDiscoveredProcesses();
   for (ProcessScanResult result : autoDiscoveryResults) {
       ProcessInfo procInfo = result.getProcessInfo();
       ....
       // as before
       DiscoveredResourceDetails detail = 
          new DiscoveredResourceDetails(
              resourceType, key, name, null,
              description, childConfig, procInfo
          );
       result.add(detail);
   }

        <metric displayName="Bytes Sent"
                description="Shows the rate that data bytes are sent by the Web service."
                property="Bytes Sent/sec"
                defaultOn="true"
                displayType="summary"
                measurementType="trendsup"
                units="bytes"/>

public class testComponent implements ResourceComponent
, MeasurementFacet
, OperationFacet

    public void getValues(MeasurementReport report, Set<MeasurementScheduleRequest> metrics) throws Exception {

        String propertyBase = "\\Web Service(_Total)\\";
        Pdh pdh = new Pdh();

        for (MeasurementScheduleRequest request : metrics) {
            double value = pdh.getRawValue(propertyBase + request.getName());
            report.addData(new MeasurementDataNumeric(request, value));
        }
}

<event name="errorLogEntry" description="an entry in the error log file"/>

    public PerfTestEventPoller(ResourceContext resourceContext) {
        this.resourceContext = resourceContext;
    }

    public String getEventType() {
        return PERFTEST_EVENT_TYPE;
    }

    public Set<Event> poll() {
        int count = Integer.parseInt(System.getProperty(SYSPROP_EVENTS_COUNT, "1"));
        String severityString = System.getProperty(SYSPROP_EVENTS_SEVERITY, EventSeverity.INFO.name());
        EventSeverity severity = EventSeverity.valueOf(severityString);
        Set<Event> events = new HashSet<Event>(count);
        for (int i = 0; i < count; i++) {
            Event event = new Event(PERFTEST_EVENT_TYPE, "source.loc", System.currentTimeMillis(), severity, "event #"
                + i);
            events.add(event);
        }
        return events;
    }

         <resource-configuration>
            <c:group name="Attributes">
               <c:simple-property
                  name="appBase"
                  required="true"
                  readOnly="true"
                  description="The Application Base directory for this virtual host." />
               <c:simple-property
                  name="autoDeploy"
                  type="boolean"
                  description="Does this host deploy new applications dropped in appBase at runtime?" />
               <c:simple-property
                  name="deployOnStartup"
                  type="boolean"
                  description="Does this host deploy applications in appBase at startup?" />
               <c:simple-property
                  name="deployXML"
                  displayName="Deploy XML"
                  type="boolean"
                  description="deploy Context XML config files?" />
               <c:simple-property
                  name="unpackWARs"
                  displayName="Unpack WARs"
                  type="boolean"
                  description="Does this Host automatically unpack deployed WAR files?" />
               <c:simple-property
                  name="aliases"
                  required="false"
                  type="longString"
                  description="Aliases assigned to the Host. When editing, each alias must be on a new line. Aliases are automatically lowercased." />
            </c:group>
         </resource-configuration>

    public Configuration loadResourceConfiguration() {
        Configuration configuration = super.loadResourceConfiguration();
        try {
            resetConfig(CONFIG_ALIASES, configuration);
        } catch (Exception e) {
            log.error("Failed to reset role property value", e);
        }

        return configuration;
    }

    public void updateResourceConfiguration(ConfigurationUpdateReport report) {
        Configuration reportConfiguration = report.getConfiguration();
        // reserve the new alias settings 
        PropertySimple newAliases = reportConfiguration.getSimple(CONFIG_ALIASES);
        // get the current alias settings
        resetConfig(CONFIG_ALIASES, reportConfiguration);
        PropertySimple currentAliases = reportConfiguration.getSimple(CONFIG_ALIASES);
        // remove the aliases config from the report so they are ignored by the mbean config processing
        reportConfiguration.remove(CONFIG_ALIASES);

        // perform standard processing on remaining config
        super.updateResourceConfiguration(report);

        // add back the aliases config so the report is complete
        reportConfiguration.put(newAliases);

        // if the mbean update failed, return now
        if (ConfigurationUpdateStatus.SUCCESS != report.getStatus()) {
            return;
        }

        // try updating the alias settings
        try {
            consolidateSettings(newAliases, currentAliases, "addAlias", "removeAlias", "alias");
        } catch (Exception e) {
            newAliases.setErrorMessage(ThrowableUtil.getStackAsString(e));
            report.setErrorMessage("Failed setting resource configuration - see property error messages for details");
            log.info("Failure setting Tomcat VHost aliases configuration value", e);
        }

        // If all went well, persist the changes to the Tomcat server.xml
        try {
            storeConfig();
        } catch (Exception e) {
            report
                .setErrorMessage("Failed to persist configuration change.  Changes will not survive Tomcat restart unless a successful Store Configuration operation is performed.");
        }
    }

<runs-inside>
   <parent-resource-type name="JMX Server" plugin="JMX" />
   <parent-resource-type name="JBoss Server" plugin="JBoss AS" />
</runs-inside>