本文介绍如何使用Alibaba Cloud SDK for Python为一个专有网络类型的ECS实例绑定一个弹性公网IP（Elastic IP Address，简称EIP）。

前提条件

在使用Alibaba Cloud SDK for Python前，您需要完成以下准备工作：
  • 您需要一个阿里云账号和访问密钥（AccessKey）。 请在阿里云控制台中的AccessKey管理页面上创建和查看您的AccessKey。
  • 确保您已经安装了Alibaba Cloud SDK for Python，请参见aliyun-python-sdk-vpc 3.0.25。
  • 下载阿里云专有网络Python SDK场景示例的VPC Python Example库。
    进入setup.py所在的目录，执行以下命令，完成环境初始化配置。 
    python setup.py install

背景信息

本文代码示例中包含以下操作：
  1. 在华东1（杭州）地域创建一个EIP。
  2. 将创建的EIP绑定到ECS。
  3. 查询绑定到ECS上的EIP。
  4. 修改EIP的带宽峰值和名称。
  5. 查询修改后的EIP。
  6. 将EIP与ECS解绑。
  7. 释放EIP。

操作步骤

  1. 在下载的SDK目录中，打开aliyun-openapi-python-sdk-examples\sdk_examples\examples\eip文件夹。
  2. 使用编辑器打开eip_quick_start.py文件，根据实际情况配置相关参数，保存退出。
    完整代码示例如下： 
    #encoding=utf-8
import sys
import json
from aliyunsdkcore.acs_exception.exceptions import ServerException, ClientException
from aliyunsdkvpc.request.v20160428 import AllocateEipAddressRequest
from aliyunsdkvpc.request.v20160428 import AssociateEipAddressRequest
from aliyunsdkvpc.request.v20160428 import DescribeEipAddressesRequest
from aliyunsdkvpc.request.v20160428 import UnassociateEipAddressRequest
from aliyunsdkvpc.request.v20160428 import ModifyEipAddressAttributeRequest
from aliyunsdkvpc.request.v20160428 import ReleaseEipAddressRequest
from sdk_lib.exception import ExceptionHandler
from sdk_lib.check_status import CheckStatus
from sdk_lib.consts import *
from sdk_lib.common_util import CommonUtil

"""
创建EIP->绑定EIP到ECS->查询EIP->修改EIP配置和名称->查询EIP->解绑EIP->释放EIP
"""
class Eip(object):
    def __init__(self, client):
        self.client = client

    def allocate_eip_address(self, params):
        """
        allocate_eip_address: 申请弹性公网IP（EIP)

        """
        try:
            request = AllocateEipAddressRequest.AllocateEipAddressRequest()
            response = self.client.do_action_with_exception(request)
            response_json = json.loads(response)
            if CheckStatus.check_status(TIME_DEFAULT_OUT, DEFAULT_TIME,
                                        self.describe_eip_status,
                                        AVAILABLE, response_json["AllocationId"]):
                return response_json
        except ServerException as e:
            ExceptionHandler.server_exception(e)
        except ClientException as e:
            ExceptionHandler.client_exception(e)

    def associate_eip_address(self, params):
        """
        associate_eip_address: 将EIP绑定到同地域的云产品实例上

        """
        try:
            request = AssociateEipAddressRequest.AssociateEipAddressRequest()
            # EIP的ID
            request.set_AllocationId(params['allocation_id'])
            # 要绑定的云产品实例的类型
            request.set_InstanceType(params['instance_type'])
            # 要绑定的实例ID
            request.set_InstanceId(params['instance_id'])
            response = self.client.do_action_with_exception(request)
            response_json = json.loads(response)
            if CheckStatus.check_status(TIME_DEFAULT_OUT, DEFAULT_TIME,
                                        self.describe_eip_status,
                                        InUse, params['allocation_id']):
                return response_json
        except ServerException as e:
            ExceptionHandler.server_exception(e)
        except ClientException as e:
            ExceptionHandler.client_exception(e)

    def describe_eip_address(self, allocation_id):
        """
        describe_eip_address: 查询指定地域已创建的EIP

        """
        try:
            request = DescribeEipAddressesRequest.DescribeEipAddressesRequest()
            # EIP的ID
            request.set_AllocationId(allocation_id)
            response = self.client.do_action_with_exception(request)
            response_json = json.loads(response)
            return response_json
        except ServerException as e:
            ExceptionHandler.server_exception(e)
        except ClientException as e:
            ExceptionHandler.client_exception(e)

    def describe_eip_status(self, allocation_id):
        """
        describe_eip_status: 查询指定地域已创建的EIP的状态

        """
        # EIP的ID
        response = self.describe_eip_address(allocation_id)
        return response["EipAddresses"]["EipAddress"][0]["Status"]


    def unassociate_eip_address(self, params):
        """
        unassociate_eip_address: 将EIP从绑定的云资源上解绑

        """
        try:
            request = UnassociateEipAddressRequest.UnassociateEipAddressRequest()
            # EIP的ID
            request.set_AllocationId(params['allocation_id'])
            # 要解绑的资源类型
            request.set_InstanceType(params['instance_type'])
            # 要解绑的云产品的实例ID
            request.set_InstanceId(params['instance_id'])
            response = self.client.do_action_with_exception(request)
            response_json = json.loads(response)
            if CheckStatus.check_status(TIME_DEFAULT_OUT, DEFAULT_TIME,
                                        self.describe_eip_status,
                                        AVAILABLE, params['allocation_id']):
                return response_json
            return response_json
        except ServerException as e:
            ExceptionHandler.server_exception(e)
        except ClientException as e:
            ExceptionHandler.client_exception(e)

    def modify_eip_address(self, params):
        """
        modify_eip_address: 修改指定EIP的名称、描述信息和带宽峰值

        """
        try:
            request = ModifyEipAddressAttributeRequest.ModifyEipAddressAttributeRequest()
            # EIP的ID
            request.set_AllocationId(params['allocation_id'])
            # EIP的带宽峰值，单位为Mbps
            request.set_Bandwidth(params['bandwidth'])
            # EIP的名称
            request.set_Name(params['name'])
            response = self.client.do_action_with_exception(request)
            response_json = json.loads(response)
            return response_json
        except ServerException as e:
            ExceptionHandler.server_exception(e)
        except ClientException as e:
            ExceptionHandler.client_exception(e)

    def release_eip_address(self, params):
        """
        release_eip_address: 释放指定的EIP

        """
        try:
            request = ReleaseEipAddressRequest.ReleaseEipAddressRequest()
            # 要释放的EIP的ID
            request.set_AllocationId(params['allocation_id'])
            response = self.client.do_action_with_exception(request)
            response_json = json.loads(response)
            return response_json
        except ServerException as e:
            ExceptionHandler.server_exception(e)
        except ClientException as e:
            ExceptionHandler.client_exception(e)

def main():

    client = AcsClient(
            '<your-access-key-id>',     # 您的AccessKey ID
            '<your-access-key-secret>', # 您的AccessKey Secret
            '<your-region-id>')         # 您的地域ID
    eip = Eip(client)
    params = {}
    # 创建EIP
    eip_response_json = eip.allocate_eip_address(params)
    CommonUtil.log("allocate_eip_address", eip_response_json)

    # 绑定EIP到ECS
    params['allocation_id'] = eip_response_json["AllocationId"]
    params['instance_id'] = ECS_INSTANCE_ID
    params['instance_type'] = 'EcsInstance'
    eip_response_json = eip.associate_eip_address(params)
    CommonUtil.log("associate_eip_address", eip_response_json)

    # 查询EIP
    eip_response_json = eip.describe_eip_address(params['allocation_id'])
    CommonUtil.log("describe_eip_address", eip_response_json)

    # 修改EIP配置和名称
    params['bandwidth'] = BANDWIDTH_50
    params['name'] = EIP_NEW_NAME
    eip_response_json = eip.modify_eip_address(params)
    CommonUtil.log("modify_eip_address", eip_response_json)

    # 查询EIP
    eip_response_json = eip.describe_eip_address(params['allocation_id'])
    CommonUtil.log("describe_eip_address", eip_response_json)

    # 解绑EIP
    eip_response_json = eip.unassociate_eip_address(params)
    CommonUtil.log("unassociate_eip_address", eip_response_json)

    # 释放EIP
    eip_response_json = eip.release_eip_address(params)
    CommonUtil.log("release_eip_address", eip_response_json)

if __name__ == '__main__':
    sys.exit(main())
  3. 进入eip_quick_start.py所在的目录，执行如下命令，将EIP绑定到ECS实例。
    python eip_quick_start.py

执行结果

系统回显结果如下： 
---------------------------allocate_eip_address---------------------------
{
  "EipAddress": "47.XX.XX.23",
  "ResourceGroupId": "rg-acfm4od****",
  "RequestId": "C438312E-F7A4-4A04-901F-D22FE23EDB4D",
  "AllocationId": "eip-bp1wybucvhhx5****"
}
---------------------------associate_eip_address---------------------------
{
  "RequestId": "6EC6605E-3D2B-4EE8-BD13-F1964CD1EAB1"
}
---------------------------describe_eip_address---------------------------
{
  "TotalCount": 1,
  "PageNumber": 1,
  "PageSize": 10,
  "EipAddresses": {
    "EipAddress": [
      {
        "ISP": "BGP",
        "ExpiredTime": "",
        "InternetChargeType": "PayByBandwidth",
        "IpAddress": "47.XX.XX.23",
        "AllocationId": "eip-bp1wybucvhhx5****",
        "PrivateIpAddress": "",
        "Status": "InUse",
        "BandwidthPackageId": "",
        "InstanceId": "i-bp1e82xlhob2****",
        "InstanceRegionId": "cn-hangzhou",
        "RegionId": "cn-hangzhou",
        "AvailableRegions": {
          "AvailableRegion": [
            "cn-hangzhou"
          ]
        },
        "ResourceGroupId": "rg-acfm4od****",
        "HasReservationData": false,
        "InstanceType": "EcsInstance",
        "AllocationTime": "2019-04-17T11:57:43Z",
        "Name": "",
        "OperationLocks": {
          "LockReason": []
        },
        "Mode": "NAT",
        "BandwidthPackageType": "",
        "BandwidthPackageBandwidth": "",
        "Bandwidth": "5",
        "HDMonitorStatus": "OFF",
        "ChargeType": "PostPaid",
        "SecondLimited": false,
        "Descritpion": ""
      }
    ]
  },
  "RequestId": "8715A878-A808-4CC4-AAD5-E414FDAB5B0E"
}
---------------------------modify_eip_address---------------------------
{
  "RequestId": "2108AE1C-94FB-475D-BFEE-EC88598BF6A6"
}
---------------------------describe_eip_address---------------------------
{
  "TotalCount": 1,
  "PageNumber": 1,
  "PageSize": 10,
  "EipAddresses": {
    "EipAddress": [
      {
        "ISP": "BGP",
        "ExpiredTime": "",
        "InternetChargeType": "PayByBandwidth",
        "IpAddress": "47.XX.XX.23",
        "AllocationId": "eip-bp1wybucvhhx5****",
        "PrivateIpAddress": "",
        "Status": "InUse",
        "BandwidthPackageId": "",
        "InstanceId": "i-bp1e82xlhob2****",
        "InstanceRegionId": "cn-hangzhou",
        "RegionId": "cn-hangzhou",
        "AvailableRegions": {
          "AvailableRegion": [
            "cn-hangzhou"
          ]
        },
        "ResourceGroupId": "rg-acfm4od****",
        "HasReservationData": false,
        "InstanceType": "EcsInstance",
        "AllocationTime": "2019-04-17T11:57:43Z",
        "Name": "EIP_NEW_NAME",
        "OperationLocks": {
          "LockReason": []
        },
        "Mode": "NAT",
        "BandwidthPackageType": "",
        "BandwidthPackageBandwidth": "",
        "Bandwidth": "50",
        "HDMonitorStatus": "OFF",
        "ChargeType": "PostPaid",
        "SecondLimited": false,
        "Descritpion": ""
      }
    ]
  },
  "RequestId": "6694D35B-B5DD-4506-8AB1-2D16477646DE"
}
---------------------------unassociate_eip_address---------------------------
{
  "RequestId": "EDE86CF6-EE68-4922-B919-85A4F11BF668"
}
---------------------------release_eip_address---------------------------
{
  "RequestId": "53FEE062-B595-4D64-AB47-834015D32888"
}