函数计算

阿里云函数计算是一个事件驱动的全托管计算服务。通过函数计算，您无需管理服务器等基础设施，只需编写代码并上传。函数计算会为您准备好计算资源，以弹性、可靠的方式运行您的代码，并提供日志查询，性能监控，报警等功能。借助于函数计算，您可以快速构建任何类型的应用和服务，无需管理和运维。更棒的是，您只需要为代码实际运行消耗的资源付费，而代码未运行则不产生费用。

函数计算中的TimeTrigger

触发器是触发函数执行的方式。有时候您不想手动调用函数执行，您希望当某件事情发生时自动触发函数的执行，这个事情就是事件源。您可以通过配置触发器的方式设置事件源触发函数执行。
例如，设置定时触发器，可以在某个时间点触发函数执行或者每隔5分钟触发函数一次；函数计算timetrigger

专题传送门 => 函数计算进行自动化运维专题

定时任务自动化场景分析

定时任务示例场景1

某些账号ak需要定期更换，以确保ak安全；
在下面的代码示例中，授权service具有访问kms权限的能力，使用kms，先对一个具有创建和删除ak权限的ak加密密文解密，获取具有创建和删除ak权限的AK, 之后利用这个AK进行ak的创建和删除操作

说明： 除了使用kms加密解密来获取较大权限的AK， 通过函数计算环境变量的设置也是一种很好的方法

操作步骤

• 创建函数,函数创建可参考函数计算helloworld

注：记得给函数的service的role设置访问kms权限

• 给函数配置定时器，详情可参考定时触发函数

• 函数代码(函数计算已经内置了相关sdk，直接使用下面的代码即可)

# -*- coding: utf-8 -*-
import logging, time, json
from aliyunsdkcore import client
from aliyunsdkram.request.v20150501.CreateAccessKeyRequest import CreateAccessKeyRequest
from aliyunsdkram.request.v20150501.DeleteAccessKeyRequest import DeleteAccessKeyRequest
from aliyunsdkkms.request.v20160120.EncryptRequest import EncryptRequest
from aliyunsdkkms.request.v20160120.DecryptRequest import DecryptRequest
from aliyunsdkcore.auth.credentials import StsTokenCredential
# ak Encrypt content
AK_CiphertextBlob = "NmQyY2ZhODMtMTlhYS00MTNjLTlmZjAtZTQxYTFiYWVmMzZmM1B1NXhTZENCNXVWd1dhdTNMWVRvb3V6dU9QcVVlMXRBQUFBQUFBQUFBQ3gwZTkzeGhDdHVzMWhDUCtZeVVuMWlobzlCa3VxMlErOXFHWWdXXXHELLwL1NSZTFvUURYSW9lak5Hak1lMnF0R2I1TWUxMEJiYmkzVnBwZHlrWGYzc3kyK2tQbGlKb2lHQ3lrZUdieHN2eXZwSVYzN2Qyd1cydz09"
USER_NAME = "ls-test" # sub-account name
LOGGER = logging.getLogger()
def handler(event, context):
  creds = context.credentials
  sts_token_credential = StsTokenCredential(creds.access_key_id, creds.access_key_secret, creds.security_token)
  # this demo ecs and function in same region, if not in same region, you need change region_id to your ecs instance's region_id
  clt = client.AcsClient(region_id=context.region, credential=sts_token_credential)
  request = DecryptRequest()
  request.set_CiphertextBlob(AK_CiphertextBlob)
  response = _send_request(clt, request)
  ak_info = json.loads(response.get("Plaintext","{}"))
  if not ak_info:
    return "KMS Decrypt ERROR"
  ak_id = ak_info["ak_id"]
  ak_secret = ak_info["ak_secret"]
  LOGGER.info("Decrypt sucessfully with key id: {}".format(response.get("KeyId","{}")))
  clt2 = client.AcsClient(ak_id, ak_secret, context.region)
  request = CreateAccessKeyRequest()
  request.set_UserName(USER_NAME) # 给子账号ls-test创建AK
  response = _send_request(clt2, request)
  create_ak_id = response.get("AccessKey",{}).get("AccessKeyId")
  if not create_ak_id:
    return
  LOGGER.info("create ak {} sucess!".format(create_ak_id))
  
  time.sleep(10)
  
  request = DeleteAccessKeyRequest()
  request.set_UserName(USER_NAME)  
  request.set_UserAccessKeyId(create_ak_id)
  response = _send_request(clt2, request)
  LOGGER.info("delete ak {} sucess!".format(create_ak_id))
  
  return "OK"
  
# send open api request
def _send_request(clt, request):
    request.set_accept_format('json')
    try:
        response_str = clt.do_action_with_exception(request)
        LOGGER.debug(response_str)
        response_detail = json.loads(response_str)
        return response_detail
    except Exception as e:
        LOGGER.error(e)

AK 存在环境变量版本

# -*- coding: utf-8 -*-
import os, logging, time, json
from aliyunsdkcore import client
from aliyunsdkram.request.v20150501.CreateAccessKeyRequest import CreateAccessKeyRequest
from aliyunsdkram.request.v20150501.DeleteAccessKeyRequest import DeleteAccessKeyRequest
USER_NAME = "ls-test" # sub-account name
LOGGER = logging.getLogger()
def handler(event, context):
  ak_id = os.environ['AK_ID']
  ak_secret = os.environ['AK_SECRET']
  clt = client.AcsClient(ak_id, ak_secret, context.region)
  request = CreateAccessKeyRequest()
  request.set_UserName(USER_NAME) # 给子账号USER_NAME创建AK
  response = _send_request(clt, request)
  create_ak_id = response.get("AccessKey", "").get("AccessKeyId")
  if not create_ak_id:
    return
  LOGGER.info("create ak {} sucess!".format(create_ak_id))
  
  time.sleep(5)
  
  request = DeleteAccessKeyRequest()
  request.set_UserName(USER_NAME)  
  request.set_UserAccessKeyId(create_ak_id)
  response = _send_request(clt, request)
  LOGGER.info("delete ak {} sucess!".format(create_ak_id))
  
  return "OK"
  
# send open api request
def _send_request(clt, request):
    request.set_accept_format('json')
    try:
        response_str = clt.do_action_with_exception(request)
        LOGGER.info(response_str)
        response_detail = json.loads(response_str)
        return response_detail
    except Exception as e:
        LOGGER.error(e)

定时任务示例场景2

定期检查自己ecs对应暴露的端口，确保安全，比如你的ecs是一个网站服务器，可能只需要对外暴露80端口就行，如果出现0.0.0.0/0这种允许所有人访问的，需要出现报警或者自动修复

操作步骤

• 创建函数,函数创建可参考函数计算helloworld

注：记得给函数的service的role设置管理ecs权限

• 给函数配置定时器，详情可参考定时触发函数

# -*- coding: utf-8 -*-
import logging
import json, random, string, time
from aliyunsdkcore import client
from aliyunsdkecs.request.v20140526.DescribeInstancesRequest import DescribeInstancesRequest
from aliyunsdkecs.request.v20140526.DescribeSecurityGroupAttributeRequest import DescribeSecurityGroupAttributeRequest
from aliyunsdkcore.auth.credentials import StsTokenCredential
LOGGER = logging.getLogger()
clt = None
# 需要检查的ecs列表, 修改成你的ecs id 列表
ECS_INST_IDS = ["i-uf6h07zdscdg9g55zkxx", "i-uf6bwkxfxh847a1e2xxx"]
def handler(event, context):
  creds = context.credentials
  global clt
  sts_token_credential = StsTokenCredential(creds.access_key_id, creds.access_key_secret, creds.security_token)
  # this demo ecs and function in same region, if not in same region, you need change region_id to your ecs instance's region_id
  clt = client.AcsClient(region_id=context.region, credential=sts_token_credential)
  invalid_perssions = {}
  for ecs_id in ECS_INST_IDS:
    ret = check_and_modify_security_rule(ecs_id)
    if ret:
      invalid_perssions[ecs_id] = ret
  return invalid_perssions
def check_and_modify_security_rule(instance_id):
  LOGGER.info("check_and_modify_security_rule, instance_id  is %s ", instance_id)
  request = DescribeInstancesRequest()
  request.set_InstanceIds(json.dumps([instance_id]))
  response = _send_request(request)
  SecurityGroupIds = []
  if response is not None:
    instance_list = response.get('Instances', {}).get('Instance')
    for item in instance_list:
      SecurityGroupIds = item.get('SecurityGroupIds', {}).get("SecurityGroupId", [])
      break
  if not SecurityGroupIds:
    LOGGER.error("ecs {} do not have SecurityGroupIds".format(instance_id))
    return 
  
  invalid_perssions = []
  
  for sg_id in SecurityGroupIds:
    request = DescribeSecurityGroupAttributeRequest()
    request.set_SecurityGroupId(sg_id)
    response = _send_request(request)
    LOGGER.info("Find a securityGroup id {}".format(sg_id))
    permissions = response.get("Permissions", {}).get("Permission",[])
    if not permissions:
      continue
    for permission in permissions:
      if permission["Direction"] == "ingress" and permission["SourceCidrIp"] == "0.0.0.0/0":
        LOGGER.error("ecs {0} , SecurityGroup id {1}, have a risk, need fix; permission = {2}".format(instance_id, sg_id, permission))
        invalid_perssions.append(permission)
        
  return invalid_perssions
# send open api request
def _send_request(request):
    request.set_accept_format('json')
    try:
        response_str = clt.do_action_with_exception(request)
        LOGGER.debug(response_str)
        response_detail = json.loads(response_str)
        return response_detail
    except Exception as e:
        LOGGER.error(e)

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