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 passing the request URI 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 the AP-Singapore region is iam.ap-southeast-3.myhwcloud.com.
• resource-path: access path of an API for performing a specified operation. Obtain the value from the URI of an API. For example, resource-path of the API used to create an IAM user is /v3.0/OS-USER/users.
• 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 means to query up to 10 pieces of data.

For example, to obtain an IAM token in the AP-Singapore region, use the endpoint (iam.ap-southeast-3.myhuaweicloud.com) of this region, and resource-path (/v3.0/OS-USER/users) in the URI of the API for creating 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, each API is provided only with resource-path and a request method, because URI-scheme of all APIs is HTTPS, and Endpoint of all APIs in the same region are identical.

Request Method

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

• GET: requests a server to return specified resources.
• PUT: requests a server to update specified resources.
• POST: requests a server to add resources or perform special operations.
• DELETE: requests a server to delete specified resources, for example, to delete an object.
• HEAD: requests a server to return the response header only.
• PATCH: requests a server to update part of a specified resource. If the resource does not exist, a new resource may be created using the PATCH method.

For example, in the URI of the API for creating 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 for the authentication information, add Content-Type, which specifies the request body type.

Common request header fields are as follows:

• Content-Type: 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: 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-Auth-Token: user token. This field is mandatory only when token-based API authentication is used. The user token is a response to the API for obtaining a user token. This API is the only one that does not require authentication.
• X-Sdk-Date: the time when a request is sent. This field is optional. When AK/SK-based authentication is enabled, this field is automatically specified when SDK is used to sign the request.
• 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 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.

In addition to supporting token-based authentication, public cloud 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.

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

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 Content-Type. The request body transfers content except the request header.

Request bodies vary with APIs. Some APIs do not require a request body, such as the APIs requested using the GET and DELETE methods.

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 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.

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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. In the response to the API for obtaining a user token, x-subject-token is the desired user token. This token can then be used to authenticate the calling of other APIs.