Question

我正在编写CF代码以启动ec2实例，这就是我的代码：

我面临以下两个问题：

1）我收到此错误“模板验证错误：模板错误：Fn :: If中未解决的条件依赖性BackupSize”

2）我想从映射USERDATA中加入参数名称。（其余的userdata可以正常工作，但是此联接无法正常工作，只是将相同的代码放入了userdata中。

有人可以帮我吗？

AWSTemplateFormatVersion: "2010-09-09"  
Description: "This template should be used to deploy ONLY test servers"  

Mappings:  

    Regions:  
    us-east-1:  
           "AMI": "ami-x"  
           "VPC": "vpc-x"  
           "SUBNET": "subnet-x"  
           "USERDATA": ".example.com"  
           "SHARE": "server1:/share"  
           "SecurityGroups": "sg-x"  
           "SecurityGroups2": "sg-y"  

Parameters:  

      ApplSize:  
      Description: "Please enter application vol. size"  
      Type: "String"  
      BackupSize:  
      Description: "Please enter backup vol. size"  
      Type: "String"  


Resources:  

      EC2Instance:  
      Type: "AWS::EC2::Instance"  
      Properties:  
            ImageId: !FindInMap [Regions, !Ref "AWS::Region", AMI]  
            InstanceType: !Ref InstanceType  
            SubnetId: !FindInMap [Regions, !Ref "AWS::Region", SUBNET]  
            SecurityGroupIds:  
                - !FindInMap [Regions, !Ref "AWS::Region", SecurityGroups]  
                - !FindInMap [Regions, !Ref "AWS::Region", SecurityGroups2]  
            BlockDeviceMappings:  
                -   
                 DeviceName : "/dev/sda1"  
                 Ebs:  
                    VolumeSize: "20"  
                    VolumeType: gp2  
                -  
                 DeviceName : "/dev/sde"  
                 Ebs:  
                    VolumeSize: !Ref ApplSize  
                    VolumeType: gp2  
                -  
                 DeviceName : "/dev/sdc"  
                 Ebs:  
                    VolumeSize: "5"  
                    VolumeType: gp2  

                - Fn::If:  
                   - BackupSize  
                   -   
                     DeviceName : "/dev/sdg"  
                     Ebs:  
                       VolumeSize: !Ref BackupSize  
                       VolumeType: gp2  
                   - !Ref "AWS::NoValue"  

      UserData:   
              Fn::Base64: !Sub |  
                #!/bin/bash  
                NEW_HOSTNAME=Fn::Join: [ " ", [ !Ref Name, Fn::FindInMap: 
                                    [Regions, !Ref "AWS::Region", USERDATA] ] ]  
                hostname $NEW_HOSTNAME  
                myshortname=`hostname -s`

如果我在参数中输入任何值，并且如果我将backupsize值留为空白，则我希望模板创建备份卷。

Answer 1

所呈现的模板的各种版本都有基本的格式设置问题。最新版本（在此答案下方的评论中附加）：

▶ aws cloudformation validate-template --template-body file://cloudformation.yml 
An error occurred (ValidationError) when calling the ValidateTemplate operation: [/Mappings/Regions] 'null' values are not allowed in templates

格式问题包括重复的键，不正确的缩进等。仅通过检查文件是否为有效的YAML不能检测到这些问题。它可以是有效的YAML，但对于Cloudformation仍然无效。您需要使用上面显示的validate-template命令。

解决了所提供模板（包括新版本）中的各种问题之后，我无法重现有关的错误

Fn :: If中未解决的条件依赖性BackupSize

您在Fn ::中拥有的东西对我来说还可以。

关于如何在Fn::Join中插值UserData：

我会考虑进行重构，以便将复杂的逻辑置于Cloudformation之外。例如，您可以将主机名作为单独的参数传递。
如果您真的想用这种方式做，可以这样：

UserData:
  Fn::Base64: !Sub
    - |
      #!/bin/bash
      NEWHOSTNAME=${newhostname}
      hostname $NEW_HOSTNAME
      myshortname=`hostname -s`
    - newhostname: !Join ["", ["foo", "bar"]]

Answer 2

AWSTemplateFormatVersion: "2010-09-09"  
Description: "This template should be used to deploy ONLY test servers"  

Mappings:  

    Regions:  
    us-east-1:  
           "AMI": "ami-x"  
           "VPC": "vpc-x"  
           "SUBNET": "subnet-x"  
           "USERDATA": ".example.com"  
           "SHARE": "server1:/share"  
           "SecurityGroups": "sg-x"  
           "SecurityGroups2": "sg-y"  

Parameters:  

      ApplSize:  
        Description: "Please enter application vol. size"  
        Type: "String"  
      BackupSize:
        Description: "Please enter backup vol. size"
        Type: "String"
      VaultSize:
        Description: "Please enter secret vol. size"
        Type: "String"
      InstanceType:
        Description: "Please select the instance type"
        Type: "String"
      Name:
        Description: "Please mention server name"
        Type: "String"
      CustomerName:
        Description: "Please mention customer name"
        Type: "String"
      Url:
        Description: "Please mention url without the domain name"
        Type: "String"


Conditions:
    BackupVol: !Equals [!Ref BackupSize, ""]


Resources:  

      EC2Instance:  
      Type: "AWS::EC2::Instance"  
      Properties:  
            ImageId: !FindInMap [Regions, !Ref "AWS::Region", AMI]  
            InstanceType: !Ref InstanceType  
            SubnetId: !FindInMap [Regions, !Ref "AWS::Region", SUBNET]  
            SecurityGroupIds:  
                - !FindInMap [Regions, !Ref "AWS::Region", SecurityGroups]  
                - !FindInMap [Regions, !Ref "AWS::Region", SecurityGroups2]  
            BlockDeviceMappings:  
                -   
                 DeviceName : "/dev/sda1"  
                 Ebs:  
                    VolumeSize: "20"  
                    VolumeType: gp2  
                -  
                 DeviceName : "/dev/sde"  
                 Ebs:  
                    VolumeSize: !Ref ApplSize  
                    VolumeType: gp2  
                -  
                 DeviceName : "/dev/sdc"  
                 Ebs:  
                    VolumeSize: "5"  
                    VolumeType: gp2  

               - Fn::If:
                   - BackupVol
                   - !Ref "AWS::NoValue"
                   - DeviceName : "/dev/sdg"
                     Ebs:
                       VolumeSize: !Ref BackupSize
                       VolumeType: gp2  

      UserData: 
              Fn::Base64: !Sub
               - |+
                  #!/bin/bash -xe
                  NEW_HOSTNAME=${test}
               - test: 
                    Fn::FindInMap: [Regions, !Ref "AWS::Region", Name]

Answer 3

简单 ans..if 的第一个条件应该是一个 CONDITIONS..创建一个条件块并在 IF 中使用它...示例：

条件：我的条件：等等

IF [我的条件：blah1, blah2]

模板验证错误：模板错误：Fn :: If中未解决的条件依赖性BackupSize

3 个答案: