Objective
To demonstrate the ability of a Fiorano REST application to interact with an end user by exposing a REST service which accepts HTTP GET requests at a URL and responds with a Hello World message.
Prerequisites
- Start Fiorano Enterprise Server (FES) and Fiorano Peer Server (FPS)
- Login to eStudio application
- Understand the basic menus and perspectives (panels) in eStudio application
Scenario
Build a REST service to accept HTTP GET requests at: http://localhost:1880/restgateway/services/HelloWorld/sayHello and respond with message "HelloWorld".
How it Works
The REST service gets deployed in the jetty server running inside the peer server and whenever a rest client sends a request to the service, the request is available on the output port and the response can be routed back by connecting a route to the input port
Components used
- RESTStub component.
Setting up the Example
Configuring RESTStub component
To configure RESTstub component, perform the following actions in eStudio application:
- Open Server Explorer window (Window > Show View > Fiorano > Server Explorer), right-click Event Process Repository and select Add Event Process and create a new Event Process with name 'RESTStub_Example'.
- In the Micro Service Palette, under Web category, drag the RESTStub component to the Fiorano Orchestrator.
Figure 1: Adding RESTStub component to Orchestrator
- Double-click the component to open the Configuration Property Sheet (CPS).
- First screen in the CPS, that is, wizard (1 of 3) is used to define the service using a user interface for WADL. User can create a WADL manually by defining different aspects of the service or can load an existing WADL and edit the configurations.
In the first screen, perform the following actions and click Next:- Provide Service Name as 'HelloWorld' with which the event process functionality is exposed as RESTful service.
Go to resource under Resources node. Under Resource Configuration tab, replace the default value of Path 'resourcePath' with 'sayHello' to give a logical meaning to the scenario.
Figure 2: Service Name and resource configuration
- Click Next in the second screen: wizard (2 of 3) where SSL Configuration, HTTP Authentication Configuration and Additional Configuration can be done (no change required for this example).
Figure 3: Clicking Next button to move to the final screen
Click Finish in the third screen, that is, wizard (3 of 3) to close the CPS and to save the configuration. The input and output ports gets generated.
Figure 4: Clicking the Finish button to save configuration
- Drag the Output port to connect it to Input port. Route will be created with default name 'route1'
Figure 5: Connecting input port to output port
Configuring Transformation
To configure transformation between input and output port, perform the following actions in the Fiorano Orchestrator:
- Right-click route1, point to Configure Transformation and select Mapper Project to open Fiorano Mapper editor.
Figure 6: Opening Mapper Project window
- In the Output Structures panel in Mapper Project, click ANY element to make it appear in Funclet View.
Figure 7: Clicking ANY element
- Click the Funclet View tab and select 'String Functions' from Function Palette (Advanced Functions drop-down in Figure 3).
Figure 8: Selecting String Functions from Function palette
- Drag and drop Constant function to Funclet easel. Connect the Source node of Constant and the Destination node of ANY (drag from the grey color box in the constant).
Figure 9: Connecting Constant function to ANY element
- Double-click the Constant present in the easel. In the String Constant dialog box, replace the default text 'Constant' with 'HelloWorld'. The name 'Constant' will be replaced with 'HelloWorld'.
Figure 10: Changing the Constant name
- Click Save icon (or File ? Save) to save the transformation configuration and close the Mapper Project editor.
Running the Example
To run the HElloWorld_example, perform the following actions in the Fiorano Orchestrator:
- Click Check Resource and Connectivity icon (or press ALT+SHIFT+C) to check resource and connectivity.
- Click Run Event Process icon (ALT+SHIFT+R) to run the event process.
- Right-click the RESTStub component and click View WADL option.
Figure 11: Navigating to view WADL
- WADL appears on your browser.
Figure 12: WADL displayed in the browser
- To access the service, type the following URL in a new tab and press ENTER to prompt a response from HelloWorld service:
http://localhost:1880/restgateway/services/HelloWorld/sayHello
Figure 13: Response from HelloWorld service
Reference
- Please note that the component options used in this example are minimum, which helps you to get an overview of the application. To explore the other options present in the RESTStub component, refer: RESTStub section.