Tutorial: Creating an invoke REST API definition

This tutorial shows you how to define and implement a REST API definition that proxies an existing service in IBM® API Connect Version 5.0.7 and later.

Before you begin

Note: For tutorials about working with the developer toolkit in IBM API Connect Version 5.0.6 and earlier, see Developer toolkit tutorials for V5.0.6 and earlier.
The following diagram shows the sequential flow through the IBM API Connect Developer toolkit tutorials for working with API definitions that call an existing endpoint. Before beginning a tutorial, ensure that you have completed the previous tutorials in the sequence. You can click a tutorial in the diagram to open the instructions for that tutorial.
Tutorial flow diagram for API definitions that call an existing endpoint Installing the toolkit Prerequisites Tutorial: Creating and publishing an API definition from the command line Tutorial: Creating an invoke REST API definition Using the Developer Portal Tutorial: Securing an API with a client ID and client secret Tutorial: Securing APIs by using an LDAP user registry Tutorial: Securing an API by using OAuth 2.0

About this tutorial

Creating a REST API definition

Add and define a REST API to return the branch details of an example BankA.

To add and define a REST API, complete the following steps:
  1. Create a folder to hold your API and Product definitions, and change to that folder in a command window.
  2. Change directories to your LoopBack® project and enter the following command:
    apic edit
    After a brief pause, the console displays this message:
    Express server listening on

    API Designer opens in your web browser, initially displaying the login page if you haven't logged in recently.

    Note: The login page prompts you to Sign in with IBM Cloud. Enter your IBM Cloud credentials, which authenticates you on IBM Cloud and provides access to the API Manager features such as Publish, Explore, and Analytics. You will continue to work in API Designer locally to create APIs, models and data sources.
    Note: If you need to run the editor on a different port, use the following command:
    [Icon indicating that this applies on Linux platforms][Icon indicating that this applies on Mac OS X platforms]
    PORT=port_number apic edit
    [Icon indicating that this applies on Windows platforms]
    set PORT=port_number && apic edit
    where port_number is the port number to use.
  3. Log in to APIConnect Designer with the appropriate method.
  4. Click Add > New API.
  5. Enter the appropriate information to create a REST API definition.
    1. In the Title field, enter Branches.
    2. The Name and Base Path fields autopopulate with the terms branches and /branches respectively.
    3. Leave the Version field at 1.0.0.
    4. Leave the default Additional properties as they are.
  6. You do not add a product at this time, click Create API.
  7. If the API Editor help screen appears, click the sentence Learn more about composing APIs, or click Got it! to access the main screen immediately.
  8. In the side bar, click Lifecycle to display the Lifecycle panel. Ensure that the Enforced, Testable, and CORS toggles are set to the On position as shown in the following screen capture:

    The Lifecycle section

  9. In the side bar, click Security Definitions to display the Security Definitions panel. Notice that clientIdHeader security definition already exists, and in the Security section you see that Option 1 is active with clientIdHeader (API Key).
  10. In the side bar, select Paths to display the Paths panel. Create a new path by clicking the Add Path icon The Add path icon.
  11. In the Path field, replace the default path segment with /details. When an operation is called, this path segment is appended to the URL of your API.

    Path screen capture

  12. By default, a single GET operation is already in your Path. Click the GET button to expand the setting dialog.
  13. For the operation, provide a summary and a description as in the following table.
    Table 1. Operation definition values
    Field Value
    Summary Branch details
    Description Retrieve details of the current branches of BankA

    The GET /details operation

  14. In the side bar, click Definitions to display the Definitions panel. Add a Definition by clicking the Add Definition icon The Add Definition icon.
  15. Expand your new definition by clicking new-definition-1. For the Name field, enter address, and a Description of The format of the address object.
  16. Using the same Definitions panel, configure the Properties definition according to the following table. Edit the default property and then create new properties by clicking Add Property and editing the default values.
    Table 2. Properties
    Property Name Description Type Example
    street1 The first line of the address string 4660 La Jolla Village Drive
    street2 The second line of the address string Suite 300
    city The city of the address string San Diego
    state The state of the address string CA
    zip_code The zip code of the address string 92122

    This is an OpenAPI (Swagger 2.0) schema definition and is presented to developers in the Developer Portal to provide them with information about the type of data to expect in their response.

    The Required The Required icon column indicates whether a property is required for success if a rest-validate policy uses the definition to perform validation. In this tutorial, no validation is performed and so none of your properties need to be marked as required.

  17. Create a second definition by clicking the Add icon The Add definition icon in the Definitions panel.
  18. Name the definition branch and, in the Description field, enter The format of the branch field.
  19. Configure the branch definition to have the properties listed in the following table by creating new properties and editing the default property. Create new properties by clicking Add Property.
    Table 3. Properties
    Property Name Description Type Example
    address The address of the branch address  
    type The type of branch string atm
    id The ID of the branch string 9d72ece0-7e7b-11e5-9038-55f9f9c08c06

    Notice that for the address property, the type of the property references another definition within your API and the example is left blank. In this manner, you can create complex data structures.

    The branch definition

  20. In the side bar, select Paths to display the Paths panel. For the /details Path, click GET to expand the available settings. Include the branch definition in the GET operation Status Code 200 response by clicking the Schema field and selecting branch from the drop-down list.
    Selecting the branch definition for the 200 response.
  21. In the submenu navigation bar, click the Assemble tab to open the assemble view.
  22. Access the invoke policy property sheet by clicking the invoke label.
  23. Populate the Title, Description, and URL fields according to the following table. When called, your API now invokes the existing Branches API and uses its response. In this tutorial, no transformations are applied to the response of this API and so the entirety of the response is returned to the caller. You can see this response at https://apictutorials.mybluemix.net/branches.
    Table 4. invoke fields
    Field Value
    Title Branches Invoke
    Description Invoke an API to retrieve the status of all branches in the BankA system
    URL https://apictutorials.mybluemix.net/branches

    Leave the remaining fields with their default values.

  24. Click the Save icon The Save icon. to save your changes.
  25. Click the Source tab to view the OpenAPI (Swagger 2.0) definition of your API. All the configuration you have performed is included in this definition, either as part of the standard OpenAPI (Swagger 2.0) schema, or as part of the x-ibm-configuration extension.

Your REST API is defined. This example helped you to configure the REST API invocation through the Assembly tool. No coding was required. The definitions help developers who are creating applications and integrating with the BankA Branches REST API for the first time.

Testing the REST API

Test your REST API to ensure that it is defined and implemented correctly.

To test the REST API, complete the following steps:
  1. Start the local test servers by completing the following steps:
    1. In the test console at the bottom of the screen, click the Start the servers icon:
      Start the servers icon
    2. Wait until the Running message is displayed:

      Depending on your project configuration and whether other processes are running, a different port number might be displayed.

    Note: If your Micro Gateway is already running, you must restart it before you can test your changes, by clicking the Restart the servers icon
    Restart the servers icon
  2. Click the Assemble tab.
  3. Click the Test icon The Test icon. The test tool opens, overlaying the palette.
  4. In the Operation section, use the drop-down menu to select the get /details operation.
  5. At the bottom of the section, click Invoke. The operation is called by the test tool. The response of your API is shown in the test tool.

In other tutorials you get a chance to test the API by using the Developer Portal and API Manager test tools, both of which run online.

Creating a Product and a Plan for the REST API

Create a Product and a Plan so that you can later stage or publish your APIs.

To create a Product, complete the following steps:
  1. Click All APIs and then click the Products tab.
  2. Click Add and then click New Product. The New Product window opens.
  3. Complete the fields as shown in the following table and then click Create product.
    Table 5. Product fields
    Field Name Value
    Title Banking Services
    Name banking-services
    Version 1.0.0
  4. In the Visibility section you can control who the Product is visible to and who can subscribe to its Plans. The Product visibility is set to Public and so anybody will be able to see the Product when it is published to the Developer Portal. When published, the Plans can be subscribed to by Authenticated users, which refers to users who have accounts in the Developer Portal.
  5. In the APIs section, click the Add API icon The Add APIs icon. The Select APIs window opens.
  6. Select the Branches API.
    The Select APIs window
  7. Click Apply.
  8. Expand the Plan titled Default that has been automatically created. Because no APIs have been excluded, the only API in the Product is included in the Plan.
  9. Enter Basic for the Title field and the Name field.
  10. Add a rate limit to your /details operation by completing the following steps:
    1. Expand the Branches API.
    2. Click Override rate limit beside the get /details operation.
    3. Use the controls to set the rate limit as 10 requests per 1 minute against rate-limit-1, and select Enforce hard limit.

      Enforcing a rate limit for an operation

  11. Click the Save icon The Save icon. to save your changes.
You have created the Banking Services Product with the Basic Plan within it, you added the Branches API to the Basic Plan, added a rate limit to the rate-limit-1 operation, and staged your Banking Services Product to your development environment.
Note: These steps are not necessary to test your APIs offline, but a Product is needed when making your APIs externally available.

Publishing your Product

Publish your Product and the API it contains to make them externally available for later tutorials.

  1. In the API Designer, click Publish and then click Add and Manage Targets.
  2. Click Add a different target.
  3. In the API Connect host address field, enter the address of your Management server, for example, example.host.com.
  4. Provide a user name and password for an API Manager account on your server and then click Sign in.
  5. In the Organization field, select the provider organization that you want to publish with.
  6. Select Sandbox from the list of Catalogs. If you have a large number of Catalogs, use the Search field to refine the list of Catalogs.
  7. Click Save.
  8. Click Publish and then click your newly created target.
  9. Select Select specific products and then select your Banking Services Product.
  10. Click Publish. Your Product is now available through your gateway server and visible in both API Manager and the Developer Portal,

Your Product and the API it contains are published to your specified target.

What you did in this tutorial

In this tutorial, you completed the following activities:
  • Created a REST API definition.
  • Tested a REST API.
  • Created a Product that contains a Plan.
  • Published a Product to a Catalog.

What to do next