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Tutorial: Use the API Management Extension for Visual Studio Code to import and manage APIs

  • Artikkel

In this tutorial, you learn how to use the API Management Extension for Visual Studio Code for common operations in API Management. Use the familiar Visual Studio Code environment to import, update, test, and manage APIs.

You learn how to:

  • Import an API into API Management
  • Edit the API
  • Apply API Management policies
  • Test the API

API in API Management Extension

For an introduction to more API Management features, see the API Management tutorials using the Azure portal.

Prerequisites

Import an API

The following example imports an OpenAPI Specification in JSON format into API Management. Microsoft provides the backend API used in this example, and hosts it on Azure at https://conferenceapi.azurewebsites.net?format=json.

  1. In Visual Studio Code, select the Azure icon from the Activity Bar.
  2. In the Explorer pane, expand the API Management instance you created.
  3. Right-click APIs, and select Import from OpenAPI Link.
  4. When prompted, enter the following values:
    1. An OpenAPI link for content in JSON format. For this example: https://conferenceapi.azurewebsites.net?format=json. This URL is the service that implements the example API. API Management forwards requests to this address.
    2. An API name, such as demo-conference-api, that is unique in the API Management instance. This name can contain only letters, number, and hyphens. The first and last characters must be alphanumeric. This name is used in the path to call the API.

After the API is imported successfully, it appears in the Explorer pane, and available API operations appear under the Operations node.

Imported API in Explorer pane

Edit the API

You can edit the API in Visual Studio Code. For example, edit the Resource Manager JSON description of the API in the editor window to remove the http protocol used to access the API.

Edit JSON description

To edit the OpenAPI format, right-click the API name in the Explorer pane and select Edit OpenAPI. Make your changes, and then select File > Save.

Apply policies to the API

API Management provides policies that you can configure for your APIs. Policies are a collection of statements. These statements are run sequentially on the request or response of an API. Policies can be global, which apply to all APIs in your API Management instance, or specific to a product, an API, or an API operation.

This section shows how to apply common outbound policies to your API that transform the API response. The policies in this example change response headers and hide original backend URLs that appear in the response body.

  1. In the Explorer pane, select Policy under the demo-conference-api that you imported. The policy file opens in the editor window. This file configures policies for all operations in the API.

  2. Update the file with the following content in the <outbound> element:

    [...]
<outbound>
    <set-header name="Custom" exists-action="override">
        <value>"My custom value"</value>
    </set-header>
    <set-header name="X-Powered-By" exists-action="delete" />
    <redirect-content-urls />
    <base />
</outbound>
[...]
    • The first set-header policy adds a custom response header for demonstration purposes.
    • The second set-header policy deletes the X-Powered-By header, if it exists. This header can reveal the application framework used in the API backend, and publishers often remove it.
    • The redirect-content-urls policy rewrites (masks) links in the response body so that they point to the equivalent links via the API Management gateway.

  3. Save the file. If you're prompted, select Upload to upload the file to the cloud.

Test the API

Get the subscription key

You need a subscription key for your API Management instance to test the imported API and the policies that are applied.

  1. In the Explorer pane, right-click the name of your API Management instance.

  2. Select Copy Subscription Key.

    Copy subscription key

Test an API operation

  1. In the Explorer pane, expand the Operations node under the demo-conference-api that you imported.
  2. Select an operation such as GetSpeakers, and then right-click the operation and select Test Operation.
  3. In the editor window, next to Ocp-Apim-Subscription-Key, replace {{SubscriptionKey}} with the subscription key that you copied.
  4. Select Send request.

Send API request from Visual Studio Code

When the request succeeds, the backend responds with 200 OK and some data.

API test operation

Notice the following details in the response:

  • The Custom header is added to the response.
  • The X-Powered-By header doesn't appear in the response.
  • URLs to the API backend are redirected to the API Management gateway, in this case https://apim-hello-world.azure-api.net/demo-conference-api.

Trace the API operation

For detailed tracing information to help you debug the API operation, select the link that appears next to Ocp-APIM-Trace-Location.

The JSON file at that location contains Inbound, Backend, and Outbound trace information. The trace information helps you determine where problems occur after the request is made.

Tip

When you test API operations, the API Management Extension allows optional policy debugging (available in the Developer service tier).

Clean up resources

When no longer needed, remove the API Management instance by right-clicking and selecting Open in Portal to delete the API Management service and its resource group.

Alternately, you can select Delete API Management to only delete the API Management instance (this operation doesn't delete its resource group).

Delete API Management instance from VS Code

Next steps

This tutorial introduced several features of the API Management Extension for Visual Studio Code. You can use these features to import and manage APIs. You learned how to:

  • Import an API into API Management
  • Edit the API
  • Apply API Management policies
  • Test the API

The API Management Extension provides more features to work with your APIs. For example, debug polices (available in the Developer service tier), or create and manage named values.