API Gateway:Use API Gateway to access an HTTP backend service

1. Create a backend service: In this step, you configure a backend service as a resource in the region where your API Gateway instance resides. You can directly select the configured backend service when you create an API.

2. Create an API group: In this step, you create an API group. APIs are managed in groups based on their business types and the business organizational structure.

3. Create an API: In this step, you create an API in the API Gateway console.

4. Create an application and authorize it to call the API: In this step, you create and authorize an application that will be used as the identity to call the API.

5. Debug the API: In this step, you verify whether the API works as expected by using the online debugging feature provided by the API Gateway console.

6. Call the API: In this step, you can use an SDK provided by API Gateway or run a cURL command in a cURL command-line tool to call the API.

1. Log on to the API Gateway console. In the top navigation bar, select a region. In the left-side navigation pane, choose Manage APIs > Backend Services. Then, click Create Backend Service in the upper-right corner.

2. In the Create Backend Service dialog box, set Name to httpd-online and Type to HTTP/HTTPS Service and click Confirm.

3. On the Backend Services page, click the httpd-online backend service. On the Backend Service Definition page, click the Production tab and then click Create in the upper-right corner.

   

4. On the Basic Information page, enter http://192.168.*.***:80 in the Backend Service URL box and click Publish.

   Note

   http://192.168.*.***:80 is the private IP address of the created ECS instance.

   

1. In the left-side navigation pane, choose Manage APIs > API Groups. On the API Groups page, click Create Group in the upper-right corner.

2. In the Create Group dialog box, select an instance from the Instances drop-down list, set Group Name to httpd-demo, set BasePath to /, and then click Confirm.

   

Create an application

1. In the left-side navigation pane, choose Call APIs > Apps. On the Apps page, click Create App in the upper-right corner.

2. Enter an application name in the App Name field and click Confirm. In this example, httpd is entered as the application name.

   

3. On the Apps page, click the httpd application that you created. On the App Details page, you can see that two authentication methods are available: AppKey and AppCode. The AppKey method includes a pair of AppKey and AppSecret, which works similarly to a pair of username and password. When you call the API, you must pass the AppKey as a parameter. The AppSecret is used to calculate signatures. API Gateway verifies the AppKey-AppSecret pair to authenticate your identity.

   

Authorize the application to call the API

1. In the left-side navigation pane, choose Manage APIs > APIs. On the APIs page, find the http-test API and click > Authorize in the Actions column.

2. On the Authorize page, set the Stage parameter to Production. Enter the name of the application you created in the search bar of the Choose Apps for Authorization section. In the search result, select the created application, click Add in the Actions column, and then click Confirm. A message appears to inform you that the application is authorized to call the API.

   

Use an SDK

1. In the left-side navigation pane, choose Call APIs > SDK. In the Sample Code for Node.js Signature in Other Languages section, select a language, for example, Node.js, and click View Sample Code for Node.js.

2. Run the $ npm install aliyun-api-gateway -S command to use nmp to install the sample SDK for Node.js.

   In the following code snippet, set YOUR_APP_KEY and YOUR_APP_SECRET to the AppKey and AppSecret of the application created in this example.

   // Import the SDK for Node.js that you downloaded.
   const Client = require('aliyun-api-gateway').Client;
   // Create an instance for the authorized application. Specify the AppKey and AppSecret of the authorized application.
   const client = new Client('YOUR_APP_KEY','YOUR_APP_SECRET');
   async function get() {
   // Use the domain name of the API group to which the API that you want to call belongs. You can use the public second-level domain name provided by API Gateway to test API calls. However, a limit is imposed on the number of API calls. We recommend that you bind an independent domain name to the API Group.
     var url = 'YOUR_GROUP_DOMAIN';
     var result = await client.get(url, {
   // Specify the request header. Some APIs can return data formats based on the specified response type. We recommend that you manually define the request header based on your business requirements. 
       headers: {
         accept: 'application/json'
       },
     });
     console.log(JSON.stringify(result));
   }
   get().catch((err) => {
     console.log(err.stack);
   });                

Use cURL

In the left-side navigation pane, choose Call APIs > Apps. On the Apps page, click the authorized application and obtain its AppCode on the page that appears. Then, use the following sample code to call the API:

curl -i -X GET "http://3fbf0648d01e4aa5a1d*******-cn-hangzhou.alicloudapi.com" -H "Authorization:APPCODE c404eca23959492b9f0e4d4d15****"