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. When obtaining an account token of the microservice engine instance, the endpoint is set to the service center address.
• resource-path: Access path of an API for performing a specified operation. Obtain the value from the URI of an API. For example, the resource-path of the API for obtaining 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 means to query up to 10 pieces of data.

For example, if you want to obtain the token of IAM in the AP-Singapore region, use the endpoint (iam.ap-southeast-3.myhuaweicloud.com) of the AP-Singapore region, find resource-path (/v3/auth/tokens) in the URI of Obtaining a User Token and combine it as follows:

https://iam.ap-southeast-3.myhuaweicloud.com/v3/auth/tokens

Figure 1 Example URI

NOTE:

To simplify the URI display, 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 a server resource header.
• PATCH: requests the server to update partial content of a specified resource. If the resource does not exist, a new resource can be created using the PATCH method.

POST https://iam.ap-southeast-3.myhuaweicloud.com/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: 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.
• 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.
• Authorization: account token of the microservice engine instance. This field is mandatory when microservice engine security authentication is used. An account token is a response to the API for Obtaining the User Token of an Exclusive ServiceComb Engine. Only this API does not require authentication.

POST https://iam.ap-southeast-3.myhuaweicloud.com/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 transfers content other than the request header. If the request body contains Chinese characters, set Content-type to utf-8, for example, Content-Type: application/json;utf-8.

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 the body included. Replace username, domainname, ******** (login password), and xxxxxxxxxxxxxxxxxx (project name) with the actual values. To learn how to obtain a project ID, see Regions and Endpoints.

NOTE:

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. For more information about this API, see Obtaining a User Token

POST https://iam.ap-southeast-3.myhuaweicloud.com/v3/auth/tokens 
Content-Type: application/json 

{ 
    "auth": { 
        "identity": { 
            "methods": [ 
                "password" 
            ], 
            "password": { 
                "user": { 
                    "name": "username", 
                    "password": "********", 
                    "domain": { 
                        "name": "domainname" 
                    } 
                } 
            } 
        }, 
        "scope": { 
            "project": { 
                "name": "xxxxxxxxxxxxxxxxxx" 
            } 
        } 
    } 
}

If all data required for the API request is available, you can send the request to call the API through curl or coding. In the response to the API used to obtain a user token, x-subject-token is the desired user token. This token can then be used to authenticate the calling of other APIs.