详解通过API管理或定制开发ECS实例_Python

弹性管理 ECS 实例

获取 RAM 子账号 AK 密钥

使用API管理ECS实例，您需要能访问ECS资源的API密钥（AccessKey ID 和 AccessKey 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用户，获取该用户的AccessKey密钥，并使用这个RAM用户和API管理ECS实例。

以下是获取RAM用户AccessKey密钥的操作步骤：

创建RAM用户并获取AccessKey密钥。

直接给RAM用户授权，授予RAM用户管理云服务器服务(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	`pip install aliyun-python-sdk-ecs`

如果提示您没有权限，请切换sudo继续执行。

1	`sudo pip install aliyun-python-sdk-ecs`

本文使用的SDK版本为 2.1.2。

Hello Alibaba Cloud

创建文件 hello_ecs_api.py。为了使用SDK，首先实例化AcsClient对象，这里需要RAM用户的AccessKey ID和AccessKey Secret。

AccessKey ID和AccessKey Secret是RAM用户访问阿里云ECS服务API的密钥，具有该账户完全的权限，请妥善保管。

									from aliyunsdkcore import client

									from aliyunsdkecs.request.v20140526.DescribeInstancesRequest import DescribeInstancesRequest

									from aliyunsdkecs.request.v20140526.DescribeRegionsRequest import DescribeRegionsRequest

									clt = client.AcsClient('Your Access Key Id', 'Your Access Key Secrect', 'cn-beijing')

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。

									def hello_aliyun_regions():

									  request = DescribeRegionsRequest()

									  response = _send_request(request)

									  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)

									def _print_region_id(item):

									  region_id = item.get("RegionId")

									  return region_id

									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)

									hello_aliyun_regions()

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：

									[u'cn-shenzhen', u'ap-southeast-1', u'cn-qingdao', u'cn-beijing', u'cn-shanghai', 

									u'us-east-1', u'cn-hongkong', u'me-east-1', u'ap-southeast-2', u'cn-hangzhou', u'eu-central-1',

									 u'ap-northeast-1', u'us-west-1']

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。

									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

输出结果为如下：

1	`current region include instance [u'i-**', u'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 Secrect', '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()