Go

Scenarios

To use Go to call an API through App authentication, obtain the Go SDK, create a new project, and then call the API by referring to the API calling example.

This section uses IntelliJ IDEA 2018.3.5 as an example.

Prerequisites

• You have obtained the domain name, request URL, and request method of the API to be called, and the AppKey and AppSecret of the app for calling the API. For more information, see Preparation.
• You have installed the Go programming language. If not, download the Go installation package from the official Go website and install it.
• You have installed IntelliJ IDEA. If not, download IntelliJ IDEA from the official IntelliJ IDEA website and install it.
• You have installed the Go plug-in on IntelliJ IDEA. If not, install the Go plug-in according to Figure 1.
  Figure 1 Installing the Go plug-in
  

Obtaining the SDK

Log in to the API Gateway console, and download the SDK on the SDKs page by referring to section "SDKs" in the User Guide.

The following table shows the files decompressed from the package.

Creating a Project

1. Start IntelliJ IDEA and choose File > New > Project.

   On the displayed New Project page, choose Go and click Next.

   Figure 2 Go
   

2. Click ..., select the directory where the SDK is decompressed, and click Finish.
   Figure 3 Selecting the SDK directory of Go after decompression
   

3. View the directory structure shown in the following figure.
   Figure 4 Directory structure of the new project go
   

   Modify the parameters in sample code demo.go as required. For details about the sample code, see API Calling Example.

API Calling Example

1. Import the Go SDK (signer.go) to the project.

   import "apig-sdk/go/core"

2. Generate a new signer and enter the AppKey and AppSecret.

   s := core.Signer{
           Key: "4f5f626b-073f-402f-a1e0-e52171c6100c",
           Secret: "******",
   }

3. Generate a new request, and specify the domain name, method, request URL, query parameters, and body.

   r, _ := http.NewRequest("POST", "http://c967a237-cd6c-470e-906f-a8655461897e.apigw.exampleRegion.com/api?a=1&b=2",
                            ioutil.NopCloser(bytes.NewBuffer([]byte("foo=bar"))))

4. Add the x-stage header to the request to specify an environment name. Add other headers to be signed as necessary.

   r.Header.Add("x-stage", "RELEASE")

5. Execute the following function to add the X-Sdk-Date and Authorization headers for signing:

   s.Sign(r)

6. Access the API and view the access result.

   resp, err := http.DefaultClient.Do(r)
   body, err := ioutil.ReadAll(resp.Body)