How to extend prototyping capabilities of WSO2 API Manager

whats covered: creating API prototypes using mediation policies for APIM 1.10.0

WSO2 API Manager comes with API prototyping capability OOTB. However if you are in need of advance prototyping capabilities or feel restricted by the available implementation for the time being you could tap into the underlying mediation engine (WSO2 ESB) to meet your prototyping need.

1) Create a mediation policy with the prototype logic

The mediation policy should be such that it respond back to the client with configured response rather than passing the message back to the backend. We can achieve this requirement using Respond[1] and Payload Factory mediators[2].

 <sequence xmlns="http://ws.apache.org/ns/synapse" name="prototypesequence">
   <header name="To" action="remove"></header>
   <header name="CustomHeader" scope="transport" value="test123"></header>
   <property name="RESPONSE" value="true"></property>
   <property name="NO_ENTITY_BODY" action="remove" scope="axis2"></property>
   <payloadFactory media-type="json">
      <format>               {"id":"101","name": "dumiduh","desc": "hard coded json"}            </format>
   </payloadFactory>
   <class name="org.wso2.carbon.apimgt.usage.publisher.APIMgtResponseHandler"/>
   <respond></respond>
</sequence>

The example above is using a hard coded response body and headers, you could also populate the response with variables as required[3]. Find the example mediation policy here [4]

 

2) Attach mediation policy to API in flow

Start creating an API with required HTTP methods etc, select Manage API from implementation and from Message Mediation Policies section upload the prototype mediation policy. Publish the API.

3) Invoke

Invoke the API as you would any other managed API.


[1] - https://docs.wso2.com/display/ESB490/Respond+Mediator
[2] - https://docs.wso2.com/display/ESB490/PayloadFactory+Mediator
[3] - https://docs.wso2.com/display/ESB490/PayloadFactory+Mediator#PayloadFactoryMediator-Example3:Addingarguments
[4] -  https://drive.google.com/file/d/0B9oVIeyHJKBXb0xkTGUwSmlJc0E/view?usp=sharing

Running a Jmeter script through Java

It may be useful to run a jmeter script through java and take actions depending on assertions in the script.

1) Creating the project

generate a java project using maven and add following dependencies,

• ApacheJMeter_core
• ApacheJMeter_http
• jorphan

further dependencies[1] may need to be put if the jmeter script being run uses samplers other than http sampler or other comps such as pre-post processors.

 

2) Code

        ....
        ....   
        StandardJMeterEngine jmeter = new StandardJMeterEngine();
       
        //Initialize Properties, logging, locale, etc.
        JMeterUtils.loadJMeterProperties(JMETERPROPFILE);
        JMeterUtils.setJMeterHome(JMETERHOME);
        JMeterUtils.initLocale();
        SaveService.loadProperties();
               
        // Load existing .jmx Test Plan
        FileInputStream in = new FileInputStream(JMETERSCRIPT);
        HashTree testPlanTree = SaveService.loadTree(in);
        in.close();
       
        // Runing JMeter Test       
        Summariser summer = new Summariser();
        String testLog = JTLHOME+new Date().getTime()+".jtl";
        MyResultCollector resultCollector = new MyResultCollector(summer);
        resultCollector.setFilename(testLog);
        testPlanTree.add(testPlanTree.getArray()[0], resultCollector);      
        jmeter.configure(testPlanTree);
        jmeter.run();
        results = resultCollector.getResults();
        ....
        ....

ResultCollector class is extended so that actions can be taken based on the assertion result.

    ....
    ....   
    @Override
        public void sampleOccurred(SampleEvent e) {
        super.sampleOccurred(e);
        SampleResult r = e.getResult();
       
        ResultDTO result = new  ResultDTO();
        result.setSamplerName(r.getSampleLabel());
        result.setResponseCode(r.getResponseCode());
        result.setResult(r.isSuccessful());               
        results.add(result);
    }
    ....
    ....



Find the full example here,
https://github.com/handakumbura/jmeterrunner