Ubuntu：无法启用服务 cfn-hup

Question

我在 CloudFormation 模板上使用自定义 Ubuntu AMI，我收到一条错误消息，上面写着 CREATE_FAILED AWS::AutoScaling::AutoScalingGroup WebServerGroup Received 0 SUCCESS signal(s) out of 1. Unable to satisfy 100% MinSuccessfulInstancesPercent requirement。我检查了/var/log/cfn-init.log 上创建的EC2 实例上的日志文件，我在日志文件上看到了Could not enable service cfn-hup。以下是我的模板部分：

"WebServerGroup": {
  "Type": "AWS::AutoScaling::AutoScalingGroup",
  "Properties": {
    "AvailabilityZones": {
      "Ref": "AZs"
    },
    "VPCZoneIdentifier": {
      "Ref": "Subnets"
    },
    "LaunchConfigurationName": {
      "Ref": "LaunchConfig"
    },
    "MinSize": "1",
    "MaxSize": "10",
    "DesiredCapacity": {
      "Ref": "InstanceCount"
    },
    "TargetGroupARNs" : [{"Ref": "TargetGroup"}],
    "Tags": [{
      "Key": "opsworks_stack_id",
      "Value": {
        "Ref": "OpsWorksStackId"
      },
      "PropagateAtLaunch": "true"
    }]
  },
  "CreationPolicy": {
    "ResourceSignal": {
      "Timeout": "PT15M"
    }
  },
  "UpdatePolicy": {
    "AutoScalingRollingUpdate": {
      "MinInstancesInService": "1",
      "MaxBatchSize": "1",
      "WaitOnResourceSignals": "true",
      "PauseTime": "PT15M"
    }
  }
},


"LaunchConfig" : {
  "Type" : "AWS::AutoScaling::LaunchConfiguration",
  "Metadata" : {
    "Comment" : "Install a simple application",
    "AWS::CloudFormation::Init" : {
      "config" : {

        "files" : {

          "/etc/cfn/cfn-hup.conf" : {
            "content" : { "Fn::Join" : ["", [
              "[main]\n",
                "stack=", { "Ref" : "AWS::StackId" }, "\n",
                "region=", { "Ref" : "AWS::Region" }, "\n"
              ]]},
            "mode"    : "000400",
            "owner"   : "root",
            "group"   : "root"
          },

          "/etc/cfn/hooks.d/cfn-auto-reloader.conf" : {
            "content": { "Fn::Join" : ["", [
              "[cfn-auto-reloader-hook]\n",
                "triggers=post.update\n",
                "path=Resources.LaunchConfig.Metadata.AWS::CloudFormation::Init\n",
                "action=/usr/local/bin/cfn-init -v ",
                "         --stack ", { "Ref" : "AWS::StackName" },
                "         --resource LaunchConfig ",
                "         --region ", { "Ref" : "AWS::Region" }, "\n",
                "runas=root\n"
              ]]}
          }
        },

        "services" : {
          "sysvinit" : {
            "cfn-hup" : { "enabled" : "true", "ensureRunning" : "true",
            "files" : ["/etc/cfn/cfn-hup.conf", "/etc/cfn/hooks.d/cfn-auto-reloader.conf"]}
            }
          }
        }
      }
    },

    "Properties" : {
      "AssociatePublicIpAddress" : "true",
      "ImageId" : { "Ref" : "AmiId" },
      "SecurityGroups" : [ { "Ref" : "LoadBalancerSecurityGroup" } ],
      "KeyName"        : { "Ref" : "KeyName" },
      "InstanceType" : { "Ref" : "InstanceType" },
      "IamInstanceProfile": {"Ref" :"RoleName"},
      "UserData"       : { "Fn::Base64" : { "Fn::Join" : ["", [
       "#!/bin/bash -xe\n",
       "easy_install https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz\n",

       "/usr/local/bin/cfn-init -v ",
       "         --stack ", { "Ref" : "AWS::StackName" },
       "         --resource LaunchConfig ",
       "         --region ", { "Ref" : "AWS::Region" }, "\n",

       "/usr/local/bin/cfn-signal -e $? ",
       "         --stack ", { "Ref" : "AWS::StackName" },
       "         --resource WebServerGroup ",
       "         --region ", { "Ref" : "AWS::Region" }, "\n",

       "sed -i'' -e 's/.*requiretty.*//' /etc/sudoers", "\n",
       "pip install --upgrade awscli", "\n",

       "INSTANCE_ID=$(aws opsworks register ",
       "         --use-instance-profile ",
       "         --infrastructure-class ec2 ",
       "         --region ", { "Ref" : "AWS::Region" },
       "         --stack-id ", { "Ref" : "OpsWorksStackId" },
       "         --override-hostname $(tr -cd 'a-z' < /dev/urandom |head -c8) --local 2>&1 |grep -o 'Instance ID: .*' |cut -d' ' -f3)", "\n",

       "aws opsworks wait instance-registered ", 
       "         --region ", { "Ref" : "AWS::Region" },
       "         --instance-id $INSTANCE_ID", "\n",

       "aws opsworks assign-instance ",
       "         --region ", { "Ref" : "AWS::Region" },
       "         --instance-id $INSTANCE_ID ",
       "         --layer-ids ", { "Ref": "OpsWorksLayerId" }, "\n"
     ]]}}
    }
  }

Answer 1

Ubuntu 18.04 和 YAML 中的新示例。它只是在 Ubuntu 实例上安装 apache2 并在其上设置 cfn-hup。这样您就可以在您的 cfn 模板中修改示例 index.html 的内容并进行更新。 cfn-hup 应该检测到更改（1 分钟间隔）并更新 index.html。

要运行它，不要忘记更新UBUNTUAMI 与您所在的地区。还需要设置SecurityGroupId在80端口允许ssh和www

---

Parameters:    

  InstanceProfile:
    Type: String
    Default: ''

  SecurityGroupId:
    Type: String

  KeyPairName: 
    Type: String
    Default: ''
    Description: A key pair for an instance for ssh    

Mappings:

  UBUNTUAMI:
    us-east-1:
      HVM64: ami-07ebfd5b3428b6f4d
    ap-southeast-2:
      HVM64: ami-02a599eb01e3b3c5b      

Conditions:

  HaveInstanceProfile:
    !Not [!Equals [!Ref InstanceProfile, '']]

  HaveKeyPair:
    !Not [!Equals [!Ref KeyPairName, '']]    


Resources:

  MyInstance1:
    Type: AWS::EC2::Instance

    CreationPolicy:
      ResourceSignal:
        Timeout: PT10M


    Metadata:
      AWS::CloudFormation::Init: 
        configSets: 
          default_install: ["apache2", "cfn-hup"]
          update_apache: ["apache2"]
        apache2: 
          packages: 
            apt:
              apache2: []
              tmux: []
              mc: []
          files: 
            /var/www/html/index.html: 
              content: |
                Hello World 1 from HOST_NAME                
          commands: 
            02_add_hostname:
              command: sed -i s/HOST_NAME/$(hostname -f)/g /var/www/html/index.html
            03_start_and_enable_apache2:
              command: "systemctl start apache2 && systemctl enable apache2"                

        cfn-hup:
          files:
            /etc/cfn/cfn-hup.conf:
              content: !Sub |
                 [main]
                 stack=${AWS::StackId}
                 region=${AWS::Region}
                 interval=1
                 verbose=true
              mode: '000400'
              owner: root
              group: root               
            /etc/cfn/hooks.d/cfn-auto-reloader.conf:
              content: !Sub |
                 [cfn-auto-reloader-hook]
                 triggers=post.update
                 path=Resources.MyInstance1.Metadata.AWS::CloudFormation::Init.apache2
                 action=/usr/local/bin/cfn-init -v --stack ${AWS::StackId} --resource MyInstance1 --region ${AWS::Region} --configsets update_apache
                 runas=root
              mode: '000400'
              owner: root
              group: root               
            /lib/systemd/system/cfn-hup.service:
              content: |
                  [Unit]
                  Description=cfn-hup daemon
                  [Service]
                  Type=simple
                  ExecStart=/usr/local/bin/cfn-hup
                  Restart=always
                  [Install]
                  WantedBy=multi-user.target                         
          commands: 
            05_start_enable_cfn-hup:
              command: "systemctl start cfn-hup && systemctl enable cfn-hup"


    Properties:                
      IamInstanceProfile: !If [HaveInstanceProfile, !Ref InstanceProfile, !Ref "AWS::NoValue"]
      ImageId: !FindInMap [UBUNTUAMI, !Ref "AWS::Region", HVM64]    
      InstanceType: t2.micro
      KeyName: !If [HaveKeyPair, !Ref KeyPairName, !Ref "AWS::NoValue"]      
      Monitoring: false            
      SecurityGroupIds: [!Ref SecurityGroupId]
      #SourceDestCheck: Boolean
      UserData: 
        Fn::Base64: !Sub |
                #!/bin/bash -xe

                apt update -y 

                apt install -y python-pip

                pip install https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz   

                /usr/local/bin/cfn-init -v \
                  --configsets default_install  \
                  --stack ${AWS::StackName} \
                  --resource MyInstance1 \
                  --region ${AWS::Region}      

                is_hup_active=$(systemctl is-active cfn-hup)  

                [[ ${!is_hup_active} == "active" ]]

                /usr/local/bin/cfn-signal -e $? \
                  --stack ${AWS::StackName} \
                  --resource MyInstance1 \
                  --region ${AWS::Region}                        
      Tags: 
        - Key: Owner
          Value: ExampleUser

Outputs:

    PublicIp:
        Value: !GetAtt MyInstance1.PublicIp

    InstanceId:
        Value: !Ref MyInstance1

Answer 2

我弄清楚我的代码有什么问题。它是cfn-hup 服务。安装后不启动。查看用户数据的变化。以下是更新后的代码。

"LaunchConfig" : {
  "Type" : "AWS::AutoScaling::LaunchConfiguration",
  "Metadata" : {
    "Comment" : "Install a simple application",
    "AWS::CloudFormation::Init" : {
      "config" : {

        "files" : {

          "/etc/cfn/cfn-hup.conf" : {
            "content" : { "Fn::Join" : ["", [
              "[main]\n",
                "stack=", { "Ref" : "AWS::StackId" }, "\n",
                "region=", { "Ref" : "AWS::Region" }, "\n"
              ]]},
            "mode"    : "000400",
            "owner"   : "root",
            "group"   : "root"
          },

          "/etc/cfn/hooks.d/cfn-auto-reloader.conf" : {
            "content": { "Fn::Join" : ["", [
              "[cfn-auto-reloader-hook]\n",
                "triggers=post.update\n",
                "path=Resources.LaunchConfig.Metadata.AWS::CloudFormation::Init\n",
                "action=/usr/local/bin/cfn-init -v ",
                "         --stack ", { "Ref" : "AWS::StackName" },
                "         --resource LaunchConfig ",
                "         --region ", { "Ref" : "AWS::Region" }, "\n",
                "runas=root\n"
              ]]}
          }
        },

        "services" : {
          "sysvinit" : {
            "cfn-hup" : { "enabled" : "true", "ensureRunning" : "true",
            "files" : ["/etc/cfn/cfn-hup.conf", "/etc/cfn/hooks.d/cfn-auto-reloader.conf"]}
            }
          }
        }
      }
    },

    "Properties" : {
      "AssociatePublicIpAddress" : "true",
      "ImageId" : { "Ref" : "AmiId" },
      "SecurityGroups" : [ { "Ref" : "LoadBalancerSecurityGroup" } ],
      "KeyName"        : { "Ref" : "KeyName" },
      "InstanceType" : { "Ref" : "InstanceType" },
      "IamInstanceProfile": {"Ref" :"RoleName"},
      "UserData"       : { "Fn::Base64" : { "Fn::Join" : ["", [
       "#!/bin/bash \n",
       "easy_install https://s3.amazonaws.com/cloudformation-examples/aws-cfn-bootstrap-latest.tar.gz\n",
       "sudo ln /usr/local/bin/cfn-hup /etc/init.d/ \n",
       "sudo initctl reload-configuration  \n",
       "sudo chmod 700 /etc/init.d/cfn-hup  \n",
       "sudo chown root:root /etc/init.d/cfn-hup \n",
       "sudo update-rc.d cfn-hup defaults  \n",
       "sudo update-rc.d cfn-hup enable  \n",
       "/usr/local/bin/cfn-init -v ",
       "         --stack ", { "Ref" : "AWS::StackName" },
       "         --resource LaunchConfig ",
       "         --region ", { "Ref" : "AWS::Region" }, "\n",

       "/usr/local/bin/cfn-signal -e $? ",
       "         --stack ", { "Ref" : "AWS::StackName" },
       "         --resource WebServerGroup ",
       "         --region ", { "Ref" : "AWS::Region" }, "\n",

       "sed -i'' -e 's/.*requiretty.*//' /etc/sudoers", "\n",
       "pip install --upgrade awscli", "\n",

       "INSTANCE_ID=$(aws opsworks register ",
       "         --use-instance-profile ",
       "         --infrastructure-class ec2 ",
       "         --region ", { "Ref" : "AWS::Region" },
       "         --stack-id ", { "Ref" : "OpsWorksStackId" },
       "         --override-hostname $(tr -cd 'a-z' < /dev/urandom |head -c8) --local 2>&1 |grep -o 'Instance ID: .*' |cut -d' ' -f3)", "\n",

       "aws opsworks wait instance-registered ", 
       "         --region ", { "Ref" : "AWS::Region" },
       "         --instance-id $INSTANCE_ID", "\n",

       "aws opsworks assign-instance ",
       "         --region ", { "Ref" : "AWS::Region" },
       "         --instance-id $INSTANCE_ID ",
       "         --layer-ids ", { "Ref": "OpsWorksLayerId" }, "\n"
     ]]}}
    }
  }