Securing web services using Talend's Open Studio for ESB - part I

This is the first part in a series of posts on securing web services using Talend's Open Studio for ESB. Talend's Open Studio for ESB is a freely available tool that comprises an eclipse-based studio to design and test web services, as well as a runtime based on Apache Karaf which can be used to deploy the web services built in the studio. In this post we will show how a simple SOAP web service can be designed and tested in the Studio.

1) Download and start the Studio and design a simple SOAP web service

Firstly download and extract Talend's Open Studio for ESB. Version 7.0.1 was used for the purpose of this blog post. The "Runtime_ESBSE" directory contains the runtime container, and the "Studio" directory the Open Studio for ESB. Launch the Studio and create a new project.

First we will create a simple SOAP "double-it" web service using the Studio. Right click on "Services" in the left-hand menu and then "Create Service". Call the service "DoubleIt" and click "Next" to create a new WSDL. The Studio then displays the design of the service, and the WSDL can be seen if you click on the "Source" tab. We will make a few changes to the default service.

Click on "DoubleItPortType" and change the operation name from "DoubleItOperation" to "DoubleIt". Next click on the right arrow next to "DoubleItRequest" and change the request type from "string" to "int". Do the same for the Response type. Now save the service and we are ready to move on to the next step.

2) Implement the "DoubleIt" service we have designed

After having designed the service above, now we need to implement the service by assigning a job to it. Right click on the "DoubleIt" service we have created ("Services/DoubleIt 0.1/DoubleItPortType 0.1/DoubleIt 0.1" in the left-hand menu) and select "Assign Job", and click "Next" to create a new job for this service. Now under "Job Designs" in the left-hand menu we see a new job has been created and the main window has been updated with tESBProviderRequest and tESBProviderResponse components.

Drag the tESBProviderResponse component over to the right hand side of the window. Now we need to think about how to handle the service logic. In our service, we want to take an input number, double it, and assign it to an output number. A Talend component available in the Studio that allows us to map XML is the "tXMLMap" component.

Find the "tXMLMap" component in the palette on the right hand side (under "XML"), and drag it onto the main window in between the two existing components. Now right click on tESBProviderRequest and select "Row" and "Main", and map the arrow onto the tXMLMap component. Do the same from tXMLMap to tESBProviderResponse, giving a name "Response" for the output when prompted.

Next we need to configure the "tXMLMap" component to implement the mapping logic. Double click on "tXMLMap". The input request is available on the left hand side, with a "root" payload. We want to map the request payload to the response payload. Hold the left mouse button down on the left-hand side over the request "root" payload, and move the mouse over to the right hand side and release on the response "root" payload, selecting "Add linker to target node".

Before we try to implement the "doubling" logic, we need to change the payload type from "String" to "int". Click on the "Tree Schema Editor" tab at the bottom of the screen and change both the request and response payload types to "int". Back up on the Response tab, click on "[row1.payload:/root]" and edit it to be "2 * [row1.payload:/root]".

Finally, we need to change the request/response elements to conform to the WSDL. Right-click on "root" in the left-hand request column and rename it to "ns2:DoubleItRequest". When this is done, right click again on this element and "Set a Namespace", with the namespace "http://www.talend.org/service/" and prefix "ns2". Similarly, on the right hand side, rename "root" to "ns2:DoubleItResponse", and set the namespace in the same way as for the request. Now click "Apply" and save the job.

Now click on the "Run" tab at the bottom of the screen and run the service. The service should now be deployed at "http://localhost:8090/services/DoubleIt".

3) Implement a client for the "DoubleIt" service

As well as designing, creating and testing web services, Talend Open Studio for ESB can also be used to create clients for these web services. To do this we need a new job. Right click on "Job Designs" in the left-hand menu and create a new job. Drag the "tESBConsumer" component to the main screen, as well as two "tLogRow" components. Right click on "tESBConsumer" and select "Row/Response" and drag the arrow to the first tLogRow component. In addition, select "Row/Fault" and drag the arrow to the second tLogRow component. This way we are logging both the response + faults from the remote service.

Left-click on "tESBConsumer" and specify "http://localhost:8090/services/DoubleIt?wsdl" as the WSDL location (the WSDL of our service is available at this address due to WSDL publish). Then click the "reload" button on the right-hand side and click "Finish". Next we need to implement the client logic - namely, to supply a number to double. Drag the "tFixedFlowInput" and "tXMLMap" components to the screen. Map "Row/Main" from "tFixedFlowInput" to "tXMLMap", and "Row" from "tXMLMap" to "tESBConsumer" with a new output name of "Request".

Now click on "tFixedFlowInput" and "Edit Schema". Add a new column of type "int" called "numberToDouble". Back in the component screen for "tFixedFlowInput" select "Use inline table" and enter a number (e.g. 200). Now click on "tXMLMap" to configure our mapping. Drag "numberToDouble" on the left-hand side over to "root" on the right-hand side, selecting "Add linker to target node". Right click on "root" on the right-hand side, and rename it to "ns2:DoubleItRequest", and again "Set a Namespace" with namespace "http://www.talend.org/service/" and prefix "ns2".

Click OK and save the job, and run it via the "Run" tab. In the console window we should see the response from the service, informing us that 200 doubled is "400". The job is also updated so that you can see the flow along with the throughput:

In the next tutorial we'll look at how to deploy our service and client jobs in the runtime container.