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, to obtain an IAM token in the AP-Singapore region, obtain the endpoint of IAM (iam.ap-southeast-3.myhuaweicloud.com) for this region and the resource-path (/v3.0/OS-USER/users) in the URI of the API used to create an IAM user. Then, construct the URI 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

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

For example, in the case of the API used to create an IAM user, the request method is POST. The request is as follows:

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

Request Header

You can also add additional header fields to a request, such as the fields required by a specified URI or HTTP method. For example, to request the authentication information, add Content-Type, which specifies the request body type.

Common request header fields are as follows:

• Content-Type: the request body type or format. This field is mandatory and its default value is application/json. Other values of this field are provided for specific APIs, if any.
• Authorization: the signature authentication information. This field is optional. When AK/SK-based authentication is enabled, this field is automatically specified when SDK is used to sign the request. For more information, see AK/SK-based Authentication.
• X-Sdk-Date: the timestamp 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-based 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. This API is the only one that does not require authentication.
• X-Project-ID: a 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 subproject through AK/SK-based authentication.
• X-Domain-ID: an account ID. This field is optional. When you call APIs of global services using AK/SK-based authentication, X-Domain-ID needs to be configured in the request header.

The following shows a request for calling 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

The body of a request is often sent in a structured format as specified in the Content-Type header field. The request body transfers content not including the request header. If the request body contains Chinese characters, these characters must be coded in UTF-8, for example, Content-Type: application/json; charset=utf-8.

Different APIs have different request body requirements. Some APIs do not even require a request body, such as the API requests using GET and DELETE.

The following shows an example request (a request body included) of the API for creating an IAM user. You can learn about request parameters and related description from this example. The bold parameters need to be replaced for a real request.

• accountid: ID of the account to which the IAM user belongs.
• username: the IAM username to be created.
• email: the email address of the IAM user.
• **********: the password of the IAM user.

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=**************** 
 
{ 
     "user": { 
         "domain_id": "accountid", 
         "name": "username", 
         "password": "**********", 
         "email": "email", 
         "description": "IAM User Description" 
     } 
 }

If all data required for the API request is available, you can send the request to call the API through curl, Postman, or coding.