Enable Job scripts and Monitor scripts to use REST web services

Requirements

• Users want to call REST web services in job scripts and monitor scripts. This includes scripts implemented with Java or JavaScript.
• The web service response should be available as an object with properties.

Feature

• JITL provides a static Java class that can be used with Java and JavaScript. This class accepts a URL and returns an object in JSON syntax.
• For use with JavaScript the JSON object can be converted to a JavaScript object.
• JavaScript sample for use with a job: this sample requests the status information from the JobScheduler Universal Agent and returns the total number of tasks that have been executed during the Agents' lifetime:

  <job  stop_on_error="no" >
      <params >
          <param  name="agent_service" value="localhost:4445/jobscheduler/agent/api/"/>
      </params>
  
      <script  language="java:javascript">
          <![CDATA[
  function spooler_process() {
  
      var parameters = spooler.create_variable_set();
      parameters.merge( spooler_task.params );
  
      var agent_service = parameters.value( "agent_service" );
      var response = com.sos.jitl.restclient.JobSchedulerRestClient.executeRestService( agent_service );
  
  //  alternative REST methods
  //  var response = com.sos.jitl.restclient.JobSchedulerRestClient.executeRestService( "http://localhost:44445/jobscheduler/agent/api/" );
  //  var response = com.sos.jitl.restclient.JobSchedulerRestClient.executeRestServiceCommand("get", "http://localhost:4445/jobscheduler/agent/api/" );
  //  var response = com.sos.jitl.restclient.JobSchedulerRestClient.getRestService( "localhost", 4445, "/jobscheduler/agent/api/", "http" );
  
      if (response) {
          eval ( "var jsonObject = " + response + ";" ); 
          spooler_log.info( jsonObject.totalTaskCount + " tasks on Agent [" + agent_service + "]: " + jsonObject.system.hostname );
      } else {
          spooler_log.error( "no response from Agent web service at: " + agent_service );
      }
  
      return (response != "");
  }
          ]]>
      </script>
  
      <run_time />
  </job>
  

Implementation

• Web Service Request
  • REST web services can be used with any of the verbs GET, POST, PUT, DELETE
  • A web service request optionally includes
    • a JSON object
    • a XML document object
    • a file
  • Header Information
    • Additional headers such as "accepted mime-type", "content-type", "user", password" etc. can be specified
• Web Service Response
  • A web service reponse optionally includes
    • a JSON object provided with the mime type "application/json"
    • a XML document object provided with the mime type "application/xml"
    • a file, e.g. from a REST Web Service that return PDF documents, including the respective response headers, e.g. "application/pdf"
  • Web Service Requests throw exceptions should an error occur. Such exceptions are handled in the job script or monitor script.