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 the request header, most programming languages or frameworks require the request URI to be transmitted separately.

• URI-scheme:

  Protocol used to transmit requests. All APIs use HTTPS.

• Endpoint:

  Domain name or IP address of the server bearing the REST service. The endpoint varies between services in different regions. It can be obtained from Regions and Endpoints.

  For example, the endpoint of IAM in region CN-Hong Kong is iam.ap-southeast-1.myhuaweicloud.com.

• resource-path:

  Access path of an API for performing a specified operation. Obtain the path from the URI of an API. For example, the resource-path of the API used to obtain a user token is /v3/auth/tokens.

• query-string:

  Query parameter, which is optional. Ensure that a question mark (?) is included before 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 will be displayed.

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

https://iam.ap-southeast-1.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 the server:

• 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: same as GET except that the server must return only the response header.
• PATCH: requests the server to update partial content of a specified resource. If the resource does not exist, a new resource will be created.

For example, in the case of the API used to obtain a user token, 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 header fields to a request, such as the fields required by a specified URI or HTTP method. For example, to request for the authentication information, add Content-Type, which specifies the request body type.

Common request header fields are as follows:

• 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: specifies 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.
• X-Sdk-Date: specifies the 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.
• 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: specifies 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: account ID, which 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.

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=****************

In addition to supporting token-based authentication, APIs also support authentication using access key ID/secret access key (AK/SK). During AK/SK-based authentication, an SDK is used to sign the request, and the Authorization (signature information) and X-Sdk-Date (time when the request is sent) header fields are automatically added to the request.

For more information, see AK/SK-based Authentication.

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 except the request header.

The request body varies between APIs. Some APIs do not require the request body, such as the APIs requested using the GET and DELETE methods.

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.

• accountid: ID of the account to which the IAM user belongs.
• 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" 
      } 
  }

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