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 the enterprise administrator.

• 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 xxx region, obtain the endpoint of IAM for this region and the resource-path in the URI of the API used to obtain a user token. Then, construct the URI as follows:

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: requests the server to return the response header only.
• 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 URI of the API for obtaining a user token, the request method is POST. The request is as follows:

POST https://Endpoint/v3/auth/tokens 

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: 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 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. For more information, see Authentication.
• X-Auth-Token: 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 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 Authentication.

The API used to obtain a user token does not require authentication. Therefore, only the Content-Type field needs to be added to requests for calling the API. An example of such requests is as follows:

POST https://Endpoint/v3/auth/tokens 
Content-Type: application/json

Request Body

The body of a request is often sent in a structured format as specified in Content-Type.

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.

For the API used to obtain a user token, 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. username indicates the username, domainname indicates the account name, ******** indicates the login password, and xxxxxxxxxxxxxxxxxx indicates the project ID. For details about how to obtain the project ID, see Obtaining an Account ID, Project ID, and Enterprise Project ID.

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.

POST https://Endpoint/v3/auth/tokens
Content-Type: application/json 
{ 
    "auth": { 
        "identity": { 
            "methods": [ 
                "password" 
            ], 
            "password": { 
                "user": { 
                    "name": "username",  
                    "password": "********", 
                    "domain": { 
                        "name": "domainname" 
                    } 
                } 
            } 
        }, 
        "scope": { 
            "project": { 
                "id": "xxxxxxxxxxxxxxxxxx"  
            } 
        } 
    }
}

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 used 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.