Making an API Request

Request URI

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

A request URI is in the following format: {URI-scheme}://{Endpoint}/{resource-path}?{query-string}

The following table describes the parameters.

For example, if you want to create an IAM user, use the endpoint of any region because IAM is a global service. Obtain the endpoint of the AP-Singapore region (iam.ap-southeast-3.myhuaweicloud.com) and find resource-path (/v3.0/OS-USER/users) in the URI of the API for creating an IAM user. Then, construct them as follows:

https://iam.ap-southeast-3.myhuaweicloud.com/v3.0/OS-USER/users

Figure 1 Example URI

To simplify the URI display in this document, each API is provided only with a resource path and a request method. The URI-scheme of all APIs is HTTPS, and the endpoints of all APIs in the same region are identical.

Request Methods

HTTP defines the following request methods that can be used to send a request to the server.

For example, in the URI of the API for creating an IAM user, the request method is POST. An example request is as follows:

POST https://iam.ap-southeast-3.myhuaweicloud.com/v3.0/OS-USER/users

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, to request for the authentication information, add Content-Type, which specifies the request body type.

Common request header fields:

• Content-Type: specifies the request body type or format. This field is mandatory and its default value is application/json. Other values of this field will be provided for specific APIs if any.
• Authorization: provides signature authentication information. This field is optional. When AK/SK authentication is enabled, this field is automatically specified for signing the request with SDK. For more information, see AK/SK Authentication.
• X-Sdk-Date: time when a request is sent. This field is optional. When AK/SK authentication is enabled, this field is automatically specified when SDK is used to sign the request. For more information, see AK/SK Authentication.
• X-Auth-Token: a user token only for token-based API authentication. The user token is a response to the API used to obtain a user token. Only this API does not require authentication.
• X-Project-ID: subproject ID. This field is optional and can be used in multi-project scenarios. The X-Project-ID field is mandatory in the request header for accessing resources in a sub-project through AK/SK authentication.
• X-Domain-ID: account ID, which is optional. When you call APIs of global services using AK/SK authentication, X-Domain-ID is needed in the request header.

The following shows an example request of the API for creating an IAM user when AK/SK authentication is used:

POST https://iam.ap-southeast-3.myhuaweicloud.com/v3.0/OS-USER/users
Content-Type: application/json
X-Sdk-Date: 20240416T095341Z 
Authorization: SDK-HMAC-SHA256 Access=****************, SignedHeaders=content-type;host;x-sdk-date, Signature=****************

Request Body

A request body is generally sent in structured format. It corresponds to Content-Type in the request header and transfers content except the request header.

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

In the case of the API used to obtain a user token, the request parameters and parameter description can be obtained from the API request. The following provides an example request with a body included. Replace the italic fields in bold with the actual values.

• Replace username with the actual username.
• domainname: account to which the user belongs
• **********: login password of the user
• xxxxxxxxxx indicates the project name, for example ap-southeast-3. You can obtain the value from Regions and Endpoints.

The scope parameter specifies where a token takes effect. You can set scope to an account or a project under an account. In the following example, the token takes effect only for the resources in a specified project. For more information about this API, see Obtaining a User Token.

POST https://iam.ap-southeast-3.myhuaweicloud.com/v3/auth/tokens
Content-Type: application/json 

{ 
    "auth": { 
        "identity": { 
            "methods": [ 
                "password" 
            ], 
            "password": { 
                "user": { 
                    "name": "username", 
                    "password": "********", 
                    "domain": { 
                        "name": "domainname" 
                    } 
                } 
            } 
        }, 
        "scope": { 
            "project": { 
                "name": "xxxxxxxx" 
            } 
        } 
    } 
}

If all data required by a request is available, you can send the request to call the API through curl, Postman, or coding. In the response to the API used to obtain a user token, x-subject-token is the desired user token. This token can then be used to authenticate the calling of other APIs.