Constructing a Request

Request URI

A request URI is in the following format:

{URI-scheme} :// {Endpoint} / {resource-path} ? {query-string}

Although a request URI is included in a request header, most programming languages or frameworks require the request URI to be separately transmitted, rather than being conveyed in a request message.

For example, to obtain the IAM token in region CN-Hong Kong, obtain the endpoint (iam.ap-southeast-1.myhuaweicloud.com) of this region and resource-path (/v3/auth/tokens) in the URI of the API for obtaining a user token. Then, assemble the fields as follows:

https://iam.ap-southeast-1.myhuaweicloud.com/v3/auth/tokens

Figure 1 Example URI

To simplify the URI display, each API provides only resource-path and the request method. This is because the URI-scheme value of all APIs is HTTPS, and the endpoints in a region are the same. Therefore, the two parts are omitted.

Request Method

HTTP-based request methods, which are also called operations or actions, specify the type of operations that you are requesting. Table 2 describes the methods supported by the REST APIs of Image Search.

For example, in the URI for obtaining a user token, the request method is POST, and the request is as follows:

POST https://iam.ap-southeast-1.myhuaweicloud.com/v3/auth/tokens

Request Header

You can add additional fields, for example, the fields required by a specified URI or HTTP method, to a request header. For example, add Content-Type that defines a request body type to request for the authentication information.

Common request headers are as follows:

In addition to supporting authentication using tokens, public cloud APIs support authentication using the AK/SK, which uses SDKs to sign a request. During the signature, the Authorization (signature authentication) and X-Sdk-Date (time when a request is sent) headers are automatically added to the request.

For more information about authentication using the AK/SK, see the API Signing Guide.

The API for obtaining a user token does not require authentication. Therefore, this API only requires adding the Content-Type field. The request with the added Content-Type header is as follows:

POST https://iam.ap-southeast-1.myhuaweicloud.com/v3/auth/tokens
Content-Type: application/json

Request Body

A request body is generally sent in structured format. It corresponds to Content-Type in the request header and transfers data except the request header. If the request body contains Chinese characters, these characters must be encoded in UTF-8.

The request body varies according to APIs. Certain APIs do not require the request body, such as the GET and DELETE APIs.

For the API of obtaining a user token, obtain the request parameters and parameter description in the API request. The following provides an example request with a body included. Replace username, domainname, ******** (login password), and xxxxxxxx (project name) with the actual values. To learn how to obtain your username, account name, and project ID, see Obtaining the Username, User ID, Project Name, and Project ID.

scope specifies where a token takes effect. In the following example, the token takes effect only on the resources specified by the project ID. You can set scope to an account or a project under an account. For details, see Obtaining a User Token..

 
POST https://iam.ap-southeast-1.myhuaweicloud.com/v3/auth/tokens
Content-Type: application/json 

{ 
    "auth": { 
        "identity": { 
            "methods": [ 
                "password" 
            ], 
            "password": { 
                "user": { 
                    "name": "username",       //Replace the value with the actual username.
                    "password": "********",   //Replace the value with the actual password.
                    "domain": { 
                        "name": "domainname"  //Replace the value with the actual domain name.
                    } 
                } 
            } 
        }, 
        "scope": { 
            "project": { 
                "name": "xxxxxxxxxx" //Replace the value with the actual project name.
            } 
        } 
    } 
}

If all data required by a request is available, you can send the request to call an API through curl, Postman, or coding. For the API of obtaining a user token, x-subject-token in the response header is the desired user token. Then, you can use the token to authenticate the calling of other APIs.