如何使用OpenAPI弹性管理ECS实例

您除了可以通过 ECS 管理控制台 创建或管理 ECS 实例外，您也能通过 OpenAPI 管理或定制开发 ECS 实例。
阿里云提供了 SDK 来包装 OpenAPI，将云服务器 ECS 的管理集成到已有系统中。本文基于 Python 的开发来说明如何通过 OpenAPI 管理 ECS 实例。如果您没有 Python 开发经验，也能通过本文完成云服务的开发。

获取 RAM 子账号 AK 密钥


使用 OpenAPI 管理 ECS 实例，您需要能访问 ECS 资源的 API 密钥（Access Key ID 和 Access Key Secret）。为了保证云服务的安全，您需要创建一个能访问 ECS 资源的 RAM 子账号，获取该子账号的 AK 密钥，并使用这个 RAM 子账号和 OpenAPI 管理 ECS 实例。
以下是获取 RAM 子账号 AK 密钥的操作步骤：

1. 创建 RAM 用户并获取 AK 密钥。
2. 直接给 RAM 用户授权，授予 RAM 子账号 [backcolor=transparent]管理云服务器服务(ECS)的权限。

安装 ECS Python SDK


首先确保您已经具备 Python 的 Runtime，本文中使用的 Python 版本为 2.7+。

1. [backcolor=transparent]pip install aliyun[backcolor=transparent]-[backcolor=transparent]python[backcolor=transparent]-[backcolor=transparent]SDK[backcolor=transparent]-[backcolor=transparent]ecs

如果提示您没有权限，请切换sudo继续执行。

1. [backcolor=transparent]sudo pip install aliyun[backcolor=transparent]-[backcolor=transparent]python[backcolor=transparent]-[backcolor=transparent]SDK[backcolor=transparent]-[backcolor=transparent]ecs

本文使用的 SDK 版本为 [backcolor=transparent]2.1.2。

Hello Alibaba Cloud


创建文件 [backcolor=transparent]hello_ecs_api.py。 为了使用 SDK，首先实例化 AcsClient 对象，这里需要 RAM 子账号的 Accesskey 和 Accesskey Secret。

Access Key ID 和 Access Key Secret 是 RAM 子账号访问阿里云 ECS 服务 API的密钥，具有该账户完全的权限，请妥善保管。

1. [backcolor=transparent]from[backcolor=transparent] aliyunSDKcore [backcolor=transparent]import[backcolor=transparent] client
2. [backcolor=transparent]from[backcolor=transparent] aliyunSDKecs[backcolor=transparent].[backcolor=transparent]request[backcolor=transparent].[backcolor=transparent]v20140526[backcolor=transparent].[backcolor=transparent]DescribeInstancesRequest[backcolor=transparent] [backcolor=transparent]import[backcolor=transparent] [backcolor=transparent]DescribeInstancesRequest
3. [backcolor=transparent]from[backcolor=transparent] aliyunSDKecs[backcolor=transparent].[backcolor=transparent]request[backcolor=transparent].[backcolor=transparent]v20140526[backcolor=transparent].[backcolor=transparent]DescribeRegionsRequest[backcolor=transparent] [backcolor=transparent]import[backcolor=transparent] [backcolor=transparent]DescribeRegionsRequest
4. [backcolor=transparent]clt [backcolor=transparent]=[backcolor=transparent] client[backcolor=transparent].[backcolor=transparent]AcsClient[backcolor=transparent]([backcolor=transparent]'Your Access Key Id'[backcolor=transparent],[backcolor=transparent] [backcolor=transparent]'Your Access Key Secret'[backcolor=transparent],[backcolor=transparent] [backcolor=transparent]'cn-beijing'[backcolor=transparent])

完成实例化后可以进行第一个应用的开发。查询当前账号支持的地域列表。具体的文档参见 查询可用地域列表。

1. [backcolor=transparent]def[backcolor=transparent] hello_aliyun_regions[backcolor=transparent]():
2. [backcolor=transparent]    request [backcolor=transparent]=[backcolor=transparent] [backcolor=transparent]DescribeRegionsRequest[backcolor=transparent]()
3. [backcolor=transparent]    response [backcolor=transparent]=[backcolor=transparent] _send_request[backcolor=transparent]([backcolor=transparent]request[backcolor=transparent])
4. [backcolor=transparent]    region_list [backcolor=transparent]=[backcolor=transparent] response[backcolor=transparent].[backcolor=transparent]get[backcolor=transparent]([backcolor=transparent]'Regions'[backcolor=transparent]).[backcolor=transparent]get[backcolor=transparent]([backcolor=transparent]'Region'[backcolor=transparent])
5. [backcolor=transparent]    [backcolor=transparent]assert[backcolor=transparent] response [backcolor=transparent]is[backcolor=transparent] [backcolor=transparent]not[backcolor=transparent] [backcolor=transparent]None
6. [backcolor=transparent]    [backcolor=transparent]assert[backcolor=transparent] region_list [backcolor=transparent]is[backcolor=transparent] [backcolor=transparent]not[backcolor=transparent] [backcolor=transparent]None
7. [backcolor=transparent]    result [backcolor=transparent]=[backcolor=transparent] map[backcolor=transparent]([backcolor=transparent]_print_region_id[backcolor=transparent],[backcolor=transparent] region_list[backcolor=transparent])
8. [backcolor=transparent]    logging[backcolor=transparent].[backcolor=transparent]info[backcolor=transparent]([backcolor=transparent]"region list: %s"[backcolor=transparent],[backcolor=transparent] result[backcolor=transparent])
10. [backcolor=transparent]def[backcolor=transparent] _print_region_id[backcolor=transparent]([backcolor=transparent]item[backcolor=transparent]):
11. [backcolor=transparent]    region_id [backcolor=transparent]=[backcolor=transparent] item[backcolor=transparent].[backcolor=transparent]get[backcolor=transparent]([backcolor=transparent]"RegionId"[backcolor=transparent])
12. [backcolor=transparent]    [backcolor=transparent]return[backcolor=transparent] region_id
14. [backcolor=transparent]def[backcolor=transparent] _send_request[backcolor=transparent]([backcolor=transparent]request[backcolor=transparent]):
15. [backcolor=transparent]    request[backcolor=transparent].[backcolor=transparent]set_accept_format[backcolor=transparent]([backcolor=transparent]'json'[backcolor=transparent])
16. [backcolor=transparent]    [backcolor=transparent]try[backcolor=transparent]:
17. [backcolor=transparent]        response_str [backcolor=transparent]=[backcolor=transparent] clt[backcolor=transparent].[backcolor=transparent]do_action[backcolor=transparent]([backcolor=transparent]request[backcolor=transparent])
18. [backcolor=transparent]        logging[backcolor=transparent].[backcolor=transparent]info[backcolor=transparent]([backcolor=transparent]response_str[backcolor=transparent])
19. [backcolor=transparent]        response_detail [backcolor=transparent]=[backcolor=transparent] json[backcolor=transparent].[backcolor=transparent]loads[backcolor=transparent]([backcolor=transparent]response_str[backcolor=transparent])
20. [backcolor=transparent]        [backcolor=transparent]return[backcolor=transparent] response_detail
21. [backcolor=transparent]    [backcolor=transparent]except[backcolor=transparent] [backcolor=transparent]Exception[backcolor=transparent] [backcolor=transparent]as[backcolor=transparent] e[backcolor=transparent]:
22. [backcolor=transparent]        logging[backcolor=transparent].[backcolor=transparent]error[backcolor=transparent]([backcolor=transparent]e[backcolor=transparent])
24. [backcolor=transparent]hello_aliyun_regions[backcolor=transparent]()

在命令行运行 python hello_ecs_api.py 会得到当前支持的 Region列表。类似的输出如下：

1. [backcolor=transparent][[backcolor=transparent]u[backcolor=transparent]'cn-shenzhen'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'ap-southeast-1'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'cn-qingdao'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'cn-beijing'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'cn-shanghai'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'us-east-1'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'cn-hongkong'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'me-east-1'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'ap-southeast-2'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'cn-hangzhou'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'eu-central-1'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'ap-northeast-1'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'us-west-1'[backcolor=transparent]]

查询当前的 Region 下的 ECS 实例列表


查询实例列表和查询 Region 列表非常类似，替换入参对象为DescribeInstancesRequest 即可，更多的查询参数参考 查询实例列表。

1. [backcolor=transparent]def[backcolor=transparent] list_instances[backcolor=transparent]():
2. [backcolor=transparent]    request [backcolor=transparent]=[backcolor=transparent] [backcolor=transparent]DescribeInstancesRequest[backcolor=transparent]()
3. [backcolor=transparent]    response [backcolor=transparent]=[backcolor=transparent] _send_request[backcolor=transparent]([backcolor=transparent]request[backcolor=transparent])
4. [backcolor=transparent]    [backcolor=transparent]if[backcolor=transparent] response [backcolor=transparent]is[backcolor=transparent] [backcolor=transparent]not[backcolor=transparent] [backcolor=transparent]None[backcolor=transparent]:
5. [backcolor=transparent]        instance_list [backcolor=transparent]=[backcolor=transparent] response[backcolor=transparent].[backcolor=transparent]get[backcolor=transparent]([backcolor=transparent]'Instances'[backcolor=transparent]).[backcolor=transparent]get[backcolor=transparent]([backcolor=transparent]'Instance'[backcolor=transparent])
6. [backcolor=transparent]        result [backcolor=transparent]=[backcolor=transparent] map[backcolor=transparent]([backcolor=transparent]_print_instance_id[backcolor=transparent],[backcolor=transparent] instance_list[backcolor=transparent])
7. [backcolor=transparent]        logging[backcolor=transparent].[backcolor=transparent]info[backcolor=transparent]([backcolor=transparent]"current region include instance %s"[backcolor=transparent],[backcolor=transparent] result[backcolor=transparent])
9. [backcolor=transparent]def[backcolor=transparent] _print_instance_id[backcolor=transparent]([backcolor=transparent]item[backcolor=transparent]):
10. [backcolor=transparent]    instance_id [backcolor=transparent]=[backcolor=transparent] item[backcolor=transparent].[backcolor=transparent]get[backcolor=transparent]([backcolor=transparent]'InstanceId'[backcolor=transparent]);
11. [backcolor=transparent]    [backcolor=transparent]return[backcolor=transparent] instance_id

输出结果为如下：

1. [backcolor=transparent]current region include instance [backcolor=transparent][[backcolor=transparent]u[backcolor=transparent]'i-****'[backcolor=transparent],[backcolor=transparent] u[backcolor=transparent]'i-****'']

更多的API参考 ECS API 概览，您可以尝试作一个 查询磁盘列表，将实例的参数替换为 DescribeDisksRequest。

完整代码示例


以上操作完整的代码示例如下所示。
#  coding=utf-8
# if the python SDK is not install using 'sudo pip install aliyun-python-SDK-ecs'
# if the python SDK is install using 'sudo pip install --upgrade aliyun-python-SDK-ecs'
# make sure the SDK version is 2.1.2, you can use command 'pip show aliyun-python-SDK-ecs' to check
import json
import logging
from aliyunSDKcore import client
from aliyunSDKecs.request.v20140526.DescribeInstancesRequest import DescribeInstancesRequest
from aliyunSDKecs.request.v20140526.DescribeRegionsRequest import DescribeRegionsRequest
# configuration the log output formatter, if you want to save the output to file,
# append ",filename='ecs_invoke.log'" after datefmt.
logging.basicConfig(level=logging.INFO,
                    format='%(asctime)s %(filename)s[line:%(lineno)d] %(levelname)s %(message)s',
                    datefmt='%a, %d %b %Y %H:%M:%S')
clt = client.AcsClient('Your Access Key Id', 'Your Access Key Secret', 'cn-beijing')
# sample api to list aliyun open api.
def hello_aliyun_regions():
    request = DescribeRegionsRequest()
    response = _send_request(request)
    if response is not None:
        region_list = response.get('Regions').get('Region')
        assert response is not None
        assert region_list is not None
        result = map(_print_region_id, region_list)
        logging.info("region list: %s", result)
# output the instance owned in current region.
def list_instances():
    request = DescribeInstancesRequest()
    response = _send_request(request)
    if response is not None:
        instance_list = response.get('Instances').get('Instance')
        result = map(_print_instance_id, instance_list)
        logging.info("current region include instance %s", result)
def _print_instance_id(item):
    instance_id = item.get('InstanceId');
    return instance_id
def _print_region_id(item):
    region_id = item.get("RegionId")
    return region_id
# send open api request
def _send_request(request):
    request.set_accept_format('json')
    try:
        response_str = clt.do_action(request)
        logging.info(response_str)
        response_detail = json.loads(response_str)
        return response_detail
    except Exception as e:
        logging.error(e)
if __name__ == '__main__':
    logging.info("Hello Aliyun OpenAPI!")
    hello_aliyun_regions()
    list_instances()
如您想了解 ECS 中 API 的其它操作，请参考 ECS中的API操作。