Making an API 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.

• URI-scheme: Protocol used to transmit requests. All APIs use HTTPS.
• Endpoint: domain name or IP address of the server running the REST service. The endpoint varies between services in different regions and can be obtained from Regions and Endpoints. For example, the endpoint of IAM in the CN Hong Kong region is iam.ap-southeast-1.myhuaweicloud.com.
• resource-path: API access path. Obtain the value from the URI of an API. For example, resource-path of the API used to create an IAM user as the administrator is /v3.0/OS-USER/users.
• query-string: Query parameter, which is optional. Ensure that a question mark (?) is included in front of each query parameter that is in the format of Parameter name=Parameter value. For example, ?limit=10 indicates that a maximum of 10 data records can be queried.

For example, to create an IAM user, obtain the endpoint of any region (for example, the endpoint of CN-Hong Kong: iam.ap-southeast-1.myhuaweicloud.com) and resource-path (/v3.0/OS-USER/users) in the URI of the API for creating an IAM user as an administrator. Then, construct the URI as follows:

https://iam.ap-southeast-1.myhuaweicloud.com/v3.0/OS-USER/users

Figure 1 Example URI

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

Request Methods

HTTP-based request methods, which are also called operations or actions, specify the type of operations that you are requesting.

• GET: requests the server to return specified resources.
• PUT: requests the server to update specified resources.
• POST: requests the server to add resources or perform special operations.
• DELETE: requests the server to delete specified resources, for example, an object.
• HEAD: requests a server resource header.
• PATCH: requests the server to update partial content of a specified resource. If the resource is unavailable, the PATCH method is used to create a resource.

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

POST https://iam.ap-southeast-1.myhuaweicloud.com/v3.0/OS-USER/users

Request Header

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

Common request headers are as follows:

• Content-Type: specifies the request body type or format. This field is mandatory and its default value is application/json. For other values, the description will be provided for specific APIs.
• Authorization: signature authentication information. This field is optional. When AK/SK authentication is enabled, this field is automatically specified when SDK is used to sign the request. For details, 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 details, see AK/SK Authentication.
• X-Auth-Token: specifies 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: 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.

For the API used to create an IAM user as the administrator, if AK/SK authentication is enabled, the request with the header is as follows:

POST https://iam.ap-southeast-1.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 a structured format as specified in Content-Type. The request body transfers content except the request header. If the request body contains Chinese characters, set Content-type to utf-8, for example, Content-Type: application/json; charset=utf-8.

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

For the API for creating an IAM user as an administrator, you can check the required request parameters and their description in the API request. The following provides an example request with a body included. Replace the italic fields in bold with the actual values.

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

POST https://iam.ap-southeast-1.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" 
     } 
 }

By now, all data required for an API request is available. You can send the request to call the API through curl, Postman, or coding.