我在2个公共子网中有2个EC2实例。EC2实例在应用程序负载均衡器中与EC2实例位于相同的公共子网中。EC2的安全组设置为只接受来自负载均衡器所在安全组的tcp流量。
当我到达应用程序负载平衡器端点时，我得到502。
我正在部署使用CloudFormation。以下是相关的代码。
AWSTemplateFormatVersion: "2010-09-09"
Description: Deploy a 3-tier wordpress system. (Plublic and Private subnets and DB on RDS)
Parameters:
VpcId:
Description: VPC id
Type: String
Default: vpc-0b6a616f830dd7d5a
PublicSubnetA:
Description: Subnet Id where instance will create
Type: String
Default: subnet-0616a6183bee2b276
PrivateSubnetA:
Description: Subnet Id where instance will create
Type: String
Default: subnet-06784a19612a64444
PublicSubnetB:
Description: Subnet Id where instance will create
Type: String
Default: subnet-04f7e39ac1431f22a
PrivateSubnetB:
Description: Subnet Id where instance will create
Type: String
Default: subnet-0fa6aa79eaee582bf
EC2KeyName:
Description: Name of an existing EC2 KeyPair to enable SSH access to the instance
Type: AWS::EC2::KeyPair::KeyName
Default: test
ConstraintDescription: must be the name of an existing EC2 KeyPair.
EC2InstanceType:
Description: EC2 instance type
Type: String
Default: t2.micro
ConstraintDescription: must be a valid EC2 instance type.
WebServerInstanceAMI:
Description: EC2 instance type
Type: AWS::EC2::Image::Id
Default: ami-0210560cedcb09f07
ConstraintDescription: must be an existing AMI ID.
SSHLocation:
Description: The IP address range that can be used to SSH to the EC2 instances
Type: String
MinLength: 9
MaxLength: 18
Default: 0.0.0.0/0
AllowedPattern: (d{1,3}).(d{1,3}).(d{1,3}).(d{1,3})/(d{1,2})
ConstraintDescription: must be a valid IP CIDR range of the form x.x.x.x/x.
Application:
Description: Application Name
Type: String
AllowedPattern: "[A-Za-z0-9-]+"
Default: test
Environment:
AllowedValues: [preprod,prod]
Default: preprod
Description: The name of the Environment
Type: String
Resources:
LoadBalancerSecurityGroup:
Type: AWS::EC2::SecurityGroup
Properties:
VpcId: !Ref VpcId
GroupDescription: ELB Security Group
SecurityGroupIngress:
- FromPort: 80
IpProtocol: tcp
CidrIp: 0.0.0.0/0
ToPort: 80
Description: Allow from internet
Tags:
- Key: Name
Value: !Sub '${Application}-loadbalancer-sg'
- Key: Project
Value: !Ref Application
WebServerSecurityGroup:
Type: AWS::EC2::SecurityGroup
Properties:
GroupDescription: 'SSH and Port 80'
VpcId:
Ref: VpcId
SecurityGroupIngress:
- IpProtocol: tcp
FromPort: 22
ToPort: 22
CidrIp: !Ref 'SSHLocation'
- IpProtocol: tcp
FromPort: 80
ToPort: 80
SourceSecurityGroupId:
Ref: LoadBalancerSecurityGroup
Tags:
- Key: Name
Value: !Sub '${Application}-webserver-sg'
- Key: Project
Value: !Ref Application
LoadBalancer:
Type: AWS::ElasticLoadBalancingV2::LoadBalancer
Properties:
Name: ApplicationLoadBalancer
Scheme: internet-facing
Subnets:
- !Ref PublicSubnetA
- !Ref PublicSubnetB
SecurityGroups:
- !Ref LoadBalancerSecurityGroup
LoadBalancerListener:
Type: AWS::ElasticLoadBalancingV2::Listener
Properties:
LoadBalancerArn: !Ref LoadBalancer
Port: 80
Protocol: HTTP
DefaultActions:
- Type: forward
TargetGroupArn: !Ref ApplicationTargetGroup
ApplicationTargetGroup:
Type: AWS::ElasticLoadBalancingV2::TargetGroup
Properties:
HealthCheckIntervalSeconds: 30
HealthCheckProtocol: HTTP
HealthCheckTimeoutSeconds: 15
HealthyThresholdCount: 3
UnhealthyThresholdCount: 3
HealthCheckPath: /index.html
Matcher:
HttpCode: '200'
Name: ApplicationTargetGroup
VpcId: !Ref VpcId
Port: 80
Protocol: HTTP
TargetGroupAttributes:
- Key: deregistration_delay.timeout_seconds
Value: '20'
Targets:
- Id: !Ref WebServerInstance1
Port: 80
- Id: !Ref WebServerInstance2
Port: 80
WebServerInstance1:
Type: AWS::EC2::Instance
Properties:
InstanceType: !Ref EC2InstanceType
KeyName: !Ref EC2KeyName
SubnetId: !Ref PublicSubnetA
SecurityGroupIds:
- !Ref WebServerSecurityGroup
ImageId: !Ref WebServerInstanceAMI
UserData:
Fn::Base64: !Sub |
#!/bin/bash -xe
cd /tmp
sudo yum update -y
sudo yum install -y httpd
echo "Welcome from the instance 1" > /var/www/html/index.html
sudo -u root service httpd start
WebServerInstance2:
Type: AWS::EC2::Instance
Properties:
InstanceType: !Ref EC2InstanceType
KeyName: !Ref EC2KeyName
SubnetId: !Ref PublicSubnetB
SecurityGroupIds:
- !Ref WebServerSecurityGroup
ImageId: !Ref WebServerInstanceAMI
UserData:
Fn::Base64: !Sub |
#!/bin/bash -xe
cd /tmp
sudo yum update -y
sudo yum install -y httpd
echo "Welcome from the instance 2" > /var/www/html/index.html
sudo -u root service httpd start
Outputs:
LoadBalancerDnsName:
Description: Load Balancer public facing DNS
Export:
Name: !Sub ${AWS::StackName}-LoadBaancer
Value: !GetAtt LoadBalancer.DNSName
我查看了控制台UI中部署的资源，我可以在EC2实例上看到正确的安全组规则。我不知道ALB何时会在向EC2实例发送消息时遇到问题。
问题:当我到达ALBs端点时，为什么我得到502错误?
I已部署您的模板在我的VPC中。模板非常好并且工作没有任何问题，包括您的负载平衡器和网站。
因此，无论导致您的问题是什么，都在这个模板之外。可能VPC定义是不正确的，但没有显示出来。如果你愿意，你可以用你的VPC设置的详细信息提出新的问题。