amazon-web-services - 基于 ELB 中的服务中主机的 CloudFormation 等待条件

Question

是否有人有以下示例(最好是 Windows)，

目前，我有一个 CF 模板，它在 ELB 下的健康主机上创建了我的 AutoScaling 组、LoadBalancer 和一些警报，并且正在正常工作，

我想要做的是在创建警报之前有一个等待条件，以便只有在主机被标记为“正在服务”但 ELB 时才创建警报。

我知道如何让等待条件发挥作用，但是我不知道如何根据 ELB 下的“服务中”状态使其发挥作用。

有人有任何建议或例子吗？我一直在网上寻找一些示例，但除了常见的 AWS 文档页面和其他一些页面之外，我无法找到我需要的内容。

我确实找到了一个关于如何验证实例运行状况的片段 - 但我无法弄清楚是否或如何将其纳入等待条件。

verify_instance_health:
commands:
ELBHealthCheck:
command: !Sub
'until ; do state=$(aws --region ${AWS::Region} elb describe-instance-health
--load-balancer-name ${ElasticLoadBalancer}
--instances $(curl -s http://169.254.169.254/latest/meta-data/instance-id)
--query InstanceStates[0].State); sleep 10; done'

干杯

Answer 1

您可以使用 Custom Resource 来完成此操作使用 DescribeInstanceHealth 监视实例API，当 EC2 实例达到 InService 状态时完成(例如，使用 instanceInService waiter 中的 AWS SDK for JavaScript )。

这是一个完整的示例，它使用 cfn-init 在 EC2 实例上配置 nginx，在 TCP 端口 80 上添加 ELB 运行状况检查，以及自定义资源 InService 等待 EC2 实例在 ELB 中InService 完成堆栈:

Description: Wait until instance enters the InService state.
Parameters:
  ImageId:
    Description: Image ID to launch EC2 instances.
    Type: AWS::EC2::Image::Id
    # amzn-ami-hvm-2016.09.1.20161221-x86_64-gp2
    Default: ami-9be6f38c
  InstanceType:
    Description: Instance type to launch EC2 instances.
    Type: String
    Default: m3.medium
    AllowedValues: [ m3.medium, m3.large, m3.xlarge, m3.2xlarge ]
  AvailabilityZones:
    Description: Availability Zones for ELB.
    Type: List<AWS::EC2::AvailabilityZone::Name>
Resources:
  InstanceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: Allow inbound traffic from Load Balancer
  SecurityGroupIngress:
    Type: AWS::EC2::SecurityGroupIngress
    Properties:
      IpProtocol: tcp
      FromPort: 80
      ToPort: 80
      GroupName: !Ref InstanceSecurityGroup
      SourceSecurityGroupName: !GetAtt LoadBalancer.SourceSecurityGroup.GroupName
      SourceSecurityGroupOwnerId: !GetAtt LoadBalancer.SourceSecurityGroup.OwnerAlias
  Instance:
    Type: AWS::EC2::Instance
    Properties:
      ImageId: !Ref ImageId
      InstanceType: !Ref InstanceType
      SecurityGroups: [!Ref InstanceSecurityGroup]
      UserData:
        "Fn::Base64": !Sub |
          #!/bin/bash
          /opt/aws/bin/cfn-init -v \
            --stack ${AWS::StackName} \
            --region ${AWS::Region} \
            --resource Instance
    Metadata:
      AWS::CloudFormation::Init:
        config:
          packages: {yum: {nginx: []}}
          services:
            sysvinit:
              nginx:
                enabled: true
                ensureRunning: true
                files: [/etc/nginx/nginx.conf]
                sources:
                - /usr/share/nginx/html
                - /etc/nginx/conf.d
                - /etc/nginx/default.d
  LoadBalancer:
    Type: AWS::ElasticLoadBalancing::LoadBalancer
    Properties:
      AvailabilityZones: !Ref AvailabilityZones
      Listeners:
      - LoadBalancerPort: 80
        InstancePort: 80
        Protocol: HTTP
      Instances: [!Ref Instance]
      HealthCheck:
        Target: TCP:80
        HealthyThreshold: 2
        UnhealthyThreshold: 5
        Interval: 5
        Timeout: 2
  InService:
    Type: Custom::InService
    Properties:
      ServiceToken: !GetAtt InServiceFunction.Arn
      Instances:
      - InstanceId: !Ref Instance
      LoadBalancerName: !Ref LoadBalancer
  InServiceFunction:
    Type: AWS::Lambda::Function
    Properties:
      Handler: index.handler
      Role: !GetAtt LambdaExecutionRole.Arn
      Code:
        ZipFile: !Sub |
          var response = require('cfn-response');
          var AWS = require('aws-sdk');
          exports.handler = (event, context) => {
            console.log("Request received:\n", JSON.stringify(event));
            var physicalId = event.PhysicalResourceId || 'none';
            var success = data => response.send(event, context, response.SUCCESS, data, physicalId);
            var failed = e => response.send(event, context, response.FAILED, e, physicalId);
            if (event.RequestType == 'Create') {
              var elb = new AWS.ELB();
              var elbParams = event.ResourceProperties;
              delete elbParams.ServiceToken;
              elb.waitFor('instanceInService', elbParams).promise().
                then((data)=> success({}), (e)=> failed(e));
            } else {
              success({});
            }
          };
      Runtime: nodejs4.3
      Timeout: 300
  LambdaExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
        - Effect: Allow
          Principal: {Service: [lambda.amazonaws.com]}
          Action: ['sts:AssumeRole']
      Path: /
      ManagedPolicyArns:
      - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
      Policies:
      - PolicyName: ELBPolicy
        PolicyDocument:
          Version: '2012-10-17'
          Statement:
            - Effect: Allow
              Action:
              - 'elasticloadbalancing:DescribeInstanceHealth'
              Resource: ['*']
Outputs:
  URL:
    Value: !Sub "http://${LoadBalancer.DNSName}"