CloudFormation 中的属性 DeviceIndex 不能为空

Question

我对 CloudFormation 非常陌生，正在尝试掌握它。作为学习过程的一部分，我尝试构建一个模板来创建 VPC、一个子网并部署面向公众的实例。下面是我在 CF 设计窗口中完成的代码。虽然我的代码验证了，但是构建时间我收到了类似的错误 -

CREATE_FAILED   AWS::EC2::Instance  AR3Web  Property DeviceIndex cannot be empty.
ROLLBACK_IN_PROGRESS    AWS::CloudFormation::Stack  Intro   The following resource(s) failed to create:[IgwAttachment, AR3Web]. . Rollback requested by user. 

我在代码中设置 DeviceIndex: '0' 。有人可以帮我理解我哪里出了问题吗？

提前感谢您的帮助。

我的代码-

---
AWSTemplateFormatVersion: 2010-09-09
Description: Test Stack
Resources:
  AR3VPC:
    Type: 'AWS::EC2::VPC'
    Properties:
      CidrBlock: 10.0.0.0/16
      EnableDnsSupport: 'true'
      EnableDnsHostnames: 'true'
      InstanceTenancy: default
      Tags:
        - Key: Name
          Value: AR3VPC
    Metadata:
      'AWS::CloudFormation::Designer':
        id: baa1b4d4-07ea-4095-b4a4-4925e7c68052
  PublicSubnet1:
    Type: 'AWS::EC2::Subnet'
    Properties:
      VpcId: !Ref AR3VPC
      CidrBlock: 10.0.1.0/24
      MapPublicIpOnLaunch: 'true'
      AvailabilityZone: us-east-1a
    Metadata:
      'AWS::CloudFormation::Designer':
        id: 24f10588-e12e-45bf-a270-c844afa4d9a7
  AR3Web:
    Type: 'AWS::EC2::Instance'
    Properties:
      ImageId: 'ami-a4c7edb2'
      InstanceType: 't2.micro'
      KeyName: virginiakp
      NetworkInterfaces:
        - GroupSet:
            - !Ref AR3WebSG
          AssociatePublicIpAddress: 'true'
          DeviceIndex: '0'
          DeleteOnTermination: 'true'
        - SubnetId: !Ref PublicSubnet1
    Metadata:
      'AWS::CloudFormation::Designer':
        id: 6080a1d9-2670-48db-abf8-a7a3ac597f2e
  AR3WebSG:
    Type: 'AWS::EC2::SecurityGroup'
    Properties:
      GroupDescription: Allow HTTP access
      SecurityGroupIngress:
        - IpProtocol: tcp
          FromPort: 80
          ToPort: 80
          CidrIp: 0.0.0.0/0
      VpcId: !Ref AR3VPC
      Tags:
        - Key: Name
          Value: AR3WebSecurityGroup
    Metadata:
      'AWS::CloudFormation::Designer':
        id: 2870d531-f538-4bee-8a03-393012432b71
  AR3IGW:
    Type: 'AWS::EC2::InternetGateway'
    Properties:
      Tags:
        - Key: Name
          Value: AR3 IGW
    Metadata:
      'AWS::CloudFormation::Designer':
        id: c2557116-9cd5-4826-9932-656e90b271a1
  AR3Rt:
    Type: 'AWS::EC2::RouteTable'
    Properties:
      VpcId: !Ref AR3VPC
    Metadata:
      'AWS::CloudFormation::Designer':
        id: e9f2dfcc-e65b-49c5-8a21-66dd3b012549
  PubRt:
    Type: 'AWS::EC2::Route'
    DependsOn: IgwAttachment
    Properties:
      RouteTableId: !Ref AR3Rt
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref AR3IGW
    Metadata:
      'AWS::CloudFormation::Designer':
        id: 37bac7d1-69ee-4c1c-9a8d-8940e586b590
  IgwAttachment:
    Type: 'AWS::EC2::VPCGatewayAttachment'
    Properties:
      InternetGatewayId: !Ref AR3IGW
      VpcId: !Ref AR3VPC
    Metadata:
      'AWS::CloudFormation::Designer':
        id: 72d68293-8163-4372-a771-1f4a4062d6dd
  PublicSubnetRouteTableAssociation:
    Type: 'AWS::EC2::SubnetRouteTableAssociation'
    Properties:
      SubnetId: !Ref PublicSubnet1
      RouteTableId: !Ref AR3Rt
    Metadata:
      'AWS::CloudFormation::Designer':
        id: 7e429e8b-2fb5-49de-a383-60ec910ed505

Answer 1

您看到该消息是因为您的网络接口数组中有拼写错误。你有：

NetworkInterfaces:
  - GroupSet:
      - !Ref AR3WebSG
    AssociatePublicIpAddress: 'true'
    DeviceIndex: '0'
    DeleteOnTermination: 'true'
  - SubnetId: !Ref PublicSubnet1

SubnetId 旁边的连字符似乎是一个拼写错误，但在 YAML 中，它表示 NetworkInterfaces 数组中的一个新元素。因此，虽然第一个元素具有 DeviceIndex: 0，但第二个元素没有 DeviceIndex，这就是您收到该消息的原因。

将其更改为：

NetworkInterfaces:
  - GroupSet:
      - !Ref AR3WebSG
    AssociatePublicIpAddress: 'true'
    DeviceIndex: '0'
    DeleteOnTermination: 'true'
    SubnetId: !Ref PublicSubnet1