AWSTemplateFormatVersion: '2010-09-09' Description: >- Account-neutral EG334S active eu-west-1b application target for the school AWS account. This permission-compatible stack creates no IAM role, Lambda, Route 53 zone, VGW, customer gateway or VPN connection. It supplies the second healthy ALB target required for the active-active application tier. Parameters: RecoverySubnetId: Type: AWS::EC2::Subnet::Id Description: Second-AZ public subnet output by hub-alb-eu-west-1.yaml. HubSecurityGroupId: { Type: 'AWS::EC2::SecurityGroup::Id' } KeyPairName: { Type: 'AWS::EC2::KeyPair::KeyName' } AlbTargetGroupArn: Type: String Description: Target group used by the Ireland Application Load Balancer. MonitoringTopicArn: { Type: String } InstanceType: Type: String Default: t3.micro AllowedValues: [t3.micro, t3.small] LatestAmiId: Type: 'AWS::SSM::Parameter::Value' Default: /aws/service/ami-amazon-linux-latest/al2023-ami-kernel-default-x86_64 Resources: SecondaryLaunchTemplate: Type: AWS::EC2::LaunchTemplate Properties: LaunchTemplateName: !Sub '${AWS::StackName}-launch-template' LaunchTemplateData: ImageId: !Ref LatestAmiId InstanceType: !Ref InstanceType KeyName: !Ref KeyPairName MetadataOptions: { HttpTokens: required, HttpEndpoint: enabled } Monitoring: { Enabled: false } NetworkInterfaces: - DeviceIndex: 0 AssociatePublicIpAddress: true Groups: [!Ref HubSecurityGroupId] DeleteOnTermination: true BlockDeviceMappings: - DeviceName: /dev/xvda Ebs: VolumeSize: 8 VolumeType: gp3 Encrypted: true DeleteOnTermination: true UserData: Fn::Base64: !Sub | #!/bin/bash set -euxo pipefail dnf install -y httpd mkdir -p /etc/systemd/system/httpd.service.d cat > /etc/systemd/system/httpd.service.d/eg334s.conf <<'EOF' [Service] Restart=always RestartSec=3 EOF TOKEN=$(curl -fsS -X PUT -H 'X-aws-ec2-metadata-token-ttl-seconds: 21600' http://169.254.169.254/latest/api/token) INSTANCE_ID=$(curl -fsS -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/instance-id) PRIVATE_IP=$(curl -fsS -H "X-aws-ec2-metadata-token: $TOKEN" http://169.254.169.254/latest/meta-data/local-ipv4) cat > /var/www/html/index.html < EG334S · active secondary AWS hub

EG334S · AWS application hub

This response is served by the active eu-west-1b application target.

EOF printf 'ok\n' > /var/www/html/health systemctl daemon-reload systemctl enable --now httpd TagSpecifications: - ResourceType: instance Tags: - { Key: Name, Value: eg334s-team2-awspublic-server-secondary } - { Key: Project, Value: EG334S } - { Key: Purpose, Value: ActiveSecondary } - ResourceType: volume Tags: - { Key: Name, Value: eg334s-team2-hub-secondary-volume } - { Key: Project, Value: EG334S } SecondaryAutoScalingGroup: Type: AWS::AutoScaling::AutoScalingGroup Properties: AutoScalingGroupName: !Sub '${AWS::StackName}-ActiveSecondaryAsg' MinSize: '1' DesiredCapacity: '1' MaxSize: '1' HealthCheckType: ELB HealthCheckGracePeriod: 300 VPCZoneIdentifier: [!Ref RecoverySubnetId] TargetGroupARNs: [!Ref AlbTargetGroupArn] MetricsCollection: - Granularity: 1Minute Metrics: - GroupInServiceInstances LaunchTemplate: LaunchTemplateId: !Ref SecondaryLaunchTemplate Version: !GetAtt SecondaryLaunchTemplate.LatestVersionNumber Tags: - { Key: Project, Value: EG334S, PropagateAtLaunch: true } - { Key: Purpose, Value: ActiveSecondary, PropagateAtLaunch: true } SecondaryCapacityAlarm: Type: AWS::CloudWatch::Alarm Properties: AlarmName: eg334s-team2-Hub-Secondary-Capacity-Low AlarmDescription: Active eu-west-1b ALB target capacity dropped below one. Namespace: AWS/AutoScaling MetricName: GroupInServiceInstances Dimensions: - Name: AutoScalingGroupName Value: !Ref SecondaryAutoScalingGroup Statistic: Minimum Period: 60 EvaluationPeriods: 2 DatapointsToAlarm: 2 Threshold: 1 ComparisonOperator: LessThanThreshold TreatMissingData: breaching AlarmActions: [!Ref MonitoringTopicArn] OKActions: [!Ref MonitoringTopicArn] Outputs: SecondaryAutoScalingGroupName: { Value: !Ref SecondaryAutoScalingGroup } SecondarySubnetId: { Value: !Ref RecoverySubnetId } OperatingModel: { Value: ACTIVE-ACTIVE-ALB-NO-CUSTOM-IAM }