函数计算

阿里云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；

专题传送门 =>

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；

说明： 除了使用kms加密解密来获取较大权限的AK， 通过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

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
  
• 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, jsonfrom aliyunsdkcore import clientfrom aliyunsdkram.request.v20150501.CreateAccessKeyRequest import CreateAccessKeyRequestfrom aliyunsdkram.request.v20150501.DeleteAccessKeyRequest import DeleteAccessKeyRequestfrom aliyunsdkkms.request.v20160120.EncryptRequest import EncryptRequestfrom aliyunsdkkms.request.v20160120.DecryptRequest import DecryptRequestfrom aliyunsdkcore.auth.credentials import StsTokenCredential# ak Encrypt contentAK_CiphertextBlob = "NmQyY2ZhODMtMTlhYS00MTNjLTlmZjAtZTQxYTFiYWVmMzZmM1B1NXhTZENCNXVWd1dhdTNMWVRvb3V6dU9QcVVlMXRBQUFBQUFBQUFBQ3gwZTkzeGhDdHVzMWhDUCtZeVVuMWlobzlCa3VxMlErOXFHWWdXXXHELLwL1NSZTFvUURYSW9lak5Hak1lMnF0R2I1TWUxMEJiYmkzVnBwZHlrWGYzc3kyK2tQbGlKb2lHQ3lrZUdieHN2eXZwSVYzN2Qyd1cydz09"USER_NAME = "ls-test" # sub-account nameLOGGER = 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 requestdef _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)

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

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

# -*- coding: utf-8 -*-import loggingimport json, random, string, timefrom aliyunsdkcore import clientfrom aliyunsdkecs.request.v20140526.DescribeInstancesRequest import DescribeInstancesRequestfrom aliyunsdkecs.request.v20140526.DescribeSecurityGroupAttributeRequest import DescribeSecurityGroupAttributeRequestfrom aliyunsdkcore.auth.credentials import StsTokenCredentialLOGGER = 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_perssionsdef 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 requestdef _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)