Making a Management Plane API Request

This section describes the structure of a REST API request on the management plane of GES, and uses the IAM API for obtaining a user token as an example to demonstrate how to call an API. The obtained token can then be used to authenticate the calling of other APIs.

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 GES in region CN North-Beijing1 is ges.cn-north-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 North-Beijing1 region, obtain the endpoint of IAM (iam.cn-north-1.myhuaweicloud.com) for this region and the resource-path (/v3/auth/tokens) in the URI of the API used to obtain a user token. Then, construct the URI as follows:

https://iam.cn-north-1.myhuaweicloud.com/v3/auth/tokens
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.cn-north-1.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:

Table 1 Common request headers

Parameter

Mandatory

Description

Example

Content-Type

Yes

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.

application/json

X-Auth-Token

This field is mandatory only for authentication using tokens.

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

No

Specifies a subproject ID. This parameter is mandatory only in multi-project scenarios.

e9993fc787d94b6c886cbaa340f9c0f4

Authorization

This field is mandatory for authentication using AK/SK.

Specifies the signature authentication information. The value is obtained from the request signing result.

-

X-Sdk-Date

This field is mandatory for authentication using AK/SK.

Specifies the time when a request is sent. The time is in YYYYMMDDTHHMMSSZ format.

The value is the current Greenwich Mean Time (GMT) time of the system.

20150907T101459Z

Host

This field is mandatory for authentication using AK/SK.

Specifies the information about the requested server. The value can be obtained from the URL of the service API. The value is in the hostname[:port] format. Default port used for https requests is port 443.

code.test.com

or

code.test.com:443

Content-Length

This field is mandatory for POST and PUT requests, but must be left blank for GET requests.

Specifies the length of the request body. The unit is byte.

3495

X-Language

No

Specifies the request language. Values include:

  • zh-cn: Chinese
  • en-us: English

en-us

In addition to supporting token-based authentication, HUAWEI 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.

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://iam.cn-north-1.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 the Content-Type header field. The request body transfers content except the request header. If the request body contains Chinese characters, these characters must be coded in 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.

For the API of obtaining a user token, obtain the request parameters and parameter description in the API request. The following provides an example request with a body included. Replace username, domianname, ******** (login password), and xxxxxxxxxxxxxxxxxx (project name) with the actual values. You can obtain the endpoint, for example, cn-north-1 from Regions and Endpoints.

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.cn-north-1.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, Postman, 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.