BlueGreenStack.yaml

# Blue/Green Cloudformation template
# Greg Heywood
# V1.0
# 14/11/2020


AWSTemplateFormatVersion: 2010-09-09
Description: Blue/Green stack
Parameters:
  SourceCodeFile:
    Type: String
    Description: Name of zip file that has been uploaded to the code repository
  BuildPhase:
    Type: 'AWS::SSM::Parameter::Value<String>'
    Default: BlueGreenPhase
    Description: This variable will determine the current phase that the environment is in - taken from SSM Parameter - BlueGreenPhase
  SourceAMI:
    Type: 'AWS::SSM::Parameter::Value<String>'
    Default: BlueGreenAMI
    Description: AMI Id - taken from SSM Parameter - BlueGreenAMI
  VpcId:
    Type: 'AWS::EC2::VPC::Id'
    Description: VpcId of your existing Virtual Private Cloud (VPC)
  Subnets:
    Type: 'List<AWS::EC2::Subnet::Id>'
    Description: The list of SubnetIds in your Virtual Private Cloud (VPC)
  LTSecurityGroups:
    Type: 'List<String>'  
    Description: The list of Security Groups used by the Launch Template
  KeyName:
    Description: Name of an existing EC2 KeyPair for access to the instances
    Type: 'AWS::EC2::KeyPair::KeyName'
  ASGMinCapacity:
    Type: Number
    Default: 1
    Description: The minimum capacity for the AutoScaling Group
  ASGMaxCapacity:
    Type: Number
    Default: 2
    Description: The maximum capacity for the AutoScaling Group
  ASGDesiredCapacity:
    Type: Number
    Default: 1
    Description: The desired capacity for the AutoScaling Group
  InstanceType:
    Type: String
    Default: 'm5.4xlarge'
    Description: Webserver instance type
  LTIamInstanceProfile:
    Type: String
    Description: Launch Configuration IAM Instance Profile
  SNSTopicForAutoScalingGroup:
    Type: String
    Description: SNS Notifications

Conditions:
  Phase2:
    !Equals [!Ref BuildPhase, Phase2]
  Phase6:
    !Equals [!Ref BuildPhase, Phase6]
  CreateStagingNLB:
    !Or [!Equals [!Ref BuildPhase, Phase2], !Equals [!Ref BuildPhase, Phase6]]
  CreateBlueASG:
    !Or [!Equals [!Ref BuildPhase, Phase1], !Equals [!Ref BuildPhase, Phase2], !Equals [!Ref BuildPhase, Phase3], !Equals [!Ref BuildPhase, Phase4], !Equals [!Ref BuildPhase, Phase6], !Equals [!Ref BuildPhase, Phase7], !Equals [!Ref BuildPhase, Phase7]]
  CreateGreenASG:
    !Or [!Equals [!Ref BuildPhase, Phase2], !Equals [!Ref BuildPhase, Phase3], !Equals [!Ref BuildPhase, Phase4],!Equals [!Ref BuildPhase, Phase5], !Equals [!Ref BuildPhase, Phase6], !Equals [!Ref BuildPhase, Phase7], !Equals [!Ref BuildPhase, Phase7]]
  BlueListeners:
    !Or [!Equals [!Ref BuildPhase, Phase1], !Equals [!Ref BuildPhase, Phase2], !Equals [!Ref BuildPhase, Phase3], !Equals [!Ref BuildPhase, Phase8]]
  GreenListeners:
    !Or [!Equals [!Ref BuildPhase, Phase4], !Equals [!Ref BuildPhase, Phase5], !Equals [!Ref BuildPhase, Phase6], !Equals [!Ref BuildPhase, Phase7]]

Resources:
#### Shared Resources ####
# Live-NLB 
  LiveElasticLoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties: 
      IpAddressType: ipv4
      Name: "BlueGreen-Live-NLB"
      Scheme: internal
      Subnets: !Ref Subnets
      LoadBalancerAttributes:
        - Key: load_balancing.cross_zone.enabled
          Value: true
      Tags: 
        - Key: "Name"
          Value: "BlueGreen-Live-NLB"
        - Key: 'CreatedBy'
          Value: !Ref 'AWS::StackName'
      Type: network

# Prod Listener 443
  ProdLBTargetGroupListener443:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      DefaultActions:
      - Type: forward
        TargetGroupArn: !If [BlueListeners, !Ref BlueLoadBalancerTargetGroup443, !Ref GreenLoadBalancerTargetGroup443]
      LoadBalancerArn: !Ref LiveElasticLoadBalancer
      Port: 443
      Protocol: TCP
# Prod Listener 80
  ProdLBTargetGroupListener80:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      DefaultActions:
      - Type: forward
        TargetGroupArn: !If [BlueListeners, !Ref BlueLoadBalancerTargetGroup80, !Ref GreenLoadBalancerTargetGroup80]
      LoadBalancerArn: !Ref LiveElasticLoadBalancer
      Port: 80
      Protocol: TCP
# Staging NLB
  StagingElasticLoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Condition: CreateStagingNLB
    Properties: 
      IpAddressType: ipv4
      Name: "BlueGreen-Staging-NLB"
      Scheme: internal
      Subnets: !Ref Subnets
      LoadBalancerAttributes:
        - Key: load_balancing.cross_zone.enabled
          Value: true
      Tags: 
        - Key: "Name"
          Value: "BlueGreen-Staging-NLB"
        - Key: 'CreatedBy'
          Value: !Ref 'AWS::StackName'
      Type: network
# Staging Listener 443
  StagingLBTargetGroupListener443:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Condition: CreateStagingNLB
    Properties:
      DefaultActions:
      - Type: forward
        TargetGroupArn: !If [Phase6, !Ref BlueLoadBalancerTargetGroup443, !If [Phase2, !Ref GreenLoadBalancerTargetGroup443, !Ref "AWS::NoValue" ]]
      LoadBalancerArn: !Ref StagingElasticLoadBalancer
      Port: 443
      Protocol: TCP
# Staging Listener 80
  StagingLBTargetGroupListener80:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Condition: CreateStagingNLB
    Properties:
      DefaultActions:
      - Type: forward
        TargetGroupArn: !If [Phase6, !Ref BlueLoadBalancerTargetGroup80, !If [Phase2, !Ref GreenLoadBalancerTargetGroup80, !Ref "AWS::NoValue" ]]
      LoadBalancerArn: !Ref StagingElasticLoadBalancer
      Port: 80
      Protocol: TCP


#### Blue Resources ####
# Blue TG 443
  BlueLoadBalancerTargetGroup443:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Condition: CreateBlueASG
    Properties:
      Name: BlueGreen-TG443-Blue
      Port: 443
      Protocol: TCP
      TargetType: instance
      VpcId: !Ref VpcId
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 60  
      Tags:
        - Key: Name
          Value: BlueGreen-TG443-Blue
        - Key: 'BuildPhase'
          Value: !Ref BuildPhase
# Blue TG 80
  BlueLoadBalancerTargetGroup80:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Condition: CreateBlueASG
    Properties:
      Name: BlueGreen-TG80-Blue
      Port: 80
      Protocol: TCP
      TargetType: instance
      VpcId: !Ref VpcId
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 60  
      Tags:
        - Key: Name
          Value: BlueGreen-TG80-Blue
        - Key: 'BuildPhase'
          Value: !Ref BuildPhase
# Blue Launch Template
  BlueLaunchTemplate:
    Type: AWS::EC2::LaunchTemplate
    Condition: CreateBlueASG
    Properties:
      LaunchTemplateData:
        InstanceType: !Ref InstanceType
        EbsOptimized: 'true'
        DisableApiTermination: 'false'
        IamInstanceProfile:
          Name: !Ref LTIamInstanceProfile
        KeyName: !Ref KeyName
        ImageId: !Ref SourceAMI
        SecurityGroupIds: !Ref LTSecurityGroups
        Monitoring:
          Enabled: True
        UserData:
          Fn::Base64:
            Fn::Sub: |
              <powershell>
              Start-Transcript -Path "C:\userdata-transcript_$(Get-Date -format 'yyyy-MM-dd_HH-mm-ss').log"
              # Whatever userdata you normally use
              Stop-Transcript
              </powershell>
              <persist>true</persist>
      LaunchTemplateName: BlueGreen-LT-BLUE
# Blue ASG (add TargetGroupARNs)
  BlueAutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Condition: CreateBlueASG
    Properties:
      AutoScalingGroupName: BlueGreen-ASG-Blue
      MinSize: !Ref ASGMinCapacity
      MaxSize: !Ref ASGMaxCapacity
      DesiredCapacity: !Ref ASGDesiredCapacity
      LaunchTemplate:
        LaunchTemplateName: BlueGreen-LT-BLUE
        Version: 1
      VPCZoneIdentifier: !Ref Subnets
      TargetGroupARNs: 
        - !Ref BlueLoadBalancerTargetGroup443
        - !Ref BlueLoadBalancerTargetGroup80
      TerminationPolicies:
        - Default
      MetricsCollection:
        - Granularity: "1Minute"
          Metrics:
          - 'GroupMaxSize'
          - 'GroupMinSize'
          - 'GroupStandbyInstances'
          - 'GroupInServiceInstances'
          - 'GroupPendingInstances'
          - 'GroupTotalInstances'
          - 'GroupDesiredCapacity'
          - 'GroupTerminatingInstances'
      NotificationConfigurations:
      - TopicARN: !Ref SNSTopicForAutoScalingGroup
        NotificationTypes:
        - autoscaling:EC2_INSTANCE_LAUNCH
        - autoscaling:EC2_INSTANCE_LAUNCH_ERROR
        - autoscaling:EC2_INSTANCE_TERMINATE
        - autoscaling:EC2_INSTANCE_TERMINATE_ERROR
      Tags: 
        - Key: "Name"
          PropagateAtLaunch: true
          Value: BlueGreen-ASG-Blue
        - Key: 'CreatedBy'
          PropagateAtLaunch: true
          Value: !Ref 'AWS::StackName'
        - Key: 'BuildPhase'
          PropagateAtLaunch: true
          Value: !Ref BuildPhase

  BlueASGScalingPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Condition: CreateBlueASG
    Properties:
      AutoScalingGroupName: !Ref BlueAutoScalingGroup
      PolicyType: TargetTrackingScaling
      EstimatedInstanceWarmup: 1100
      TargetTrackingConfiguration:
        PredefinedMetricSpecification:
          PredefinedMetricType: ASGAverageCPUUtilization
        TargetValue: 50

  BlueASGLifeCycleHook:
    Type: AWS::AutoScaling::LifecycleHook
    Condition: CreateBlueASG
    Properties:
      AutoScalingGroupName: !Ref BlueAutoScalingGroup
      DefaultResult: CONTINUE
      HeartbeatTimeout: 600
      LifecycleHookName: RemoveFromDomainHook
      LifecycleTransition: autoscaling:EC2_INSTANCE_TERMINATING

#### Green Resources ####
# Green TG 443
  GreenLoadBalancerTargetGroup443:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Condition: CreateGreenASG
    Properties:
      Name: BlueGreen-TG443-Green
      Port: 443
      Protocol: TCP
      TargetType: instance
      VpcId: !Ref VpcId
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 60  
      Tags:
        - Key: Name
          Value: BlueGreen-TG443-Green
        - Key: 'BuildPhase'
          Value: !Ref BuildPhase
# Green TG 80
  GreenLoadBalancerTargetGroup80:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Condition: CreateGreenASG
    Properties:
      Name: BlueGreen-TG80-Green
      Port: 80
      Protocol: TCP
      TargetType: instance
      VpcId: !Ref VpcId
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 60  
      Tags:
        - Key: Name
          Value: BlueGreen-TG443-Green
        - Key: 'BuildPhase'
          Value: !Ref BuildPhase
# Green Launch Template
  GreenLaunchTemplate:
    Type: AWS::EC2::LaunchTemplate
    Condition: CreateGreenASG
    Properties:
      LaunchTemplateData:
        InstanceType: !Ref InstanceType
        EbsOptimized: 'true'
        DisableApiTermination: 'false'
        IamInstanceProfile:
          Name: !Ref LTIamInstanceProfile
        KeyName: !Ref KeyName
        ImageId: !Ref SourceAMI
        SecurityGroupIds: !Ref LTSecurityGroups
        Monitoring:
          Enabled: True
        UserData:
          Fn::Base64:
            Fn::Sub: |
              <powershell>
              Start-Transcript -Path "C:\userdata-transcript_$(Get-Date -format 'yyyy-MM-dd_HH-mm-ss').log"
              # Whatever userdata you normally use
              Stop-Transcript
              </powershell>
              <persist>true</persist>
      LaunchTemplateName: BlueGreen-LT-GREEN
# Green ASG (add TargetGroupARNs)
  GreenAutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    Condition: CreateGreenASG
    Properties:
      AutoScalingGroupName: BlueGreen-ASG-Green
      MinSize: !Ref ASGMinCapacity
      MaxSize: !Ref ASGMaxCapacity
      DesiredCapacity: !Ref ASGDesiredCapacity
      LaunchTemplate:
        LaunchTemplateName: BlueGreen-LT-GREEN
        Version: 1
      VPCZoneIdentifier: !Ref Subnets
      TargetGroupARNs:
        - !Ref GreenLoadBalancerTargetGroup443
        - !Ref GreenLoadBalancerTargetGroup80
      TerminationPolicies:
        - Default
      MetricsCollection:
        - Granularity: "1Minute"
          Metrics:
          - 'GroupMaxSize'
          - 'GroupMinSize'
          - 'GroupStandbyInstances'
          - 'GroupInServiceInstances'
          - 'GroupPendingInstances'
          - 'GroupTotalInstances'
          - 'GroupDesiredCapacity'
          - 'GroupTerminatingInstances'
      NotificationConfigurations:
      - TopicARN: !Ref SNSTopicForAutoScalingGroup
        NotificationTypes:
        - autoscaling:EC2_INSTANCE_LAUNCH
        - autoscaling:EC2_INSTANCE_LAUNCH_ERROR
        - autoscaling:EC2_INSTANCE_TERMINATE
        - autoscaling:EC2_INSTANCE_TERMINATE_ERROR
      Tags: 
        - Key: "Name"
          PropagateAtLaunch: true
          Value: BlueGreen-ASG-Green
        - Key: 'CreatedBy'
          PropagateAtLaunch: true
          Value: !Ref 'AWS::StackName'
        - Key: 'BuildPhase'
          PropagateAtLaunch: true
          Value: !Ref BuildPhase

  GreenASGScalingPolicy:
    Type: AWS::AutoScaling::ScalingPolicy
    Condition: CreateGreenASG
    Properties:
      AutoScalingGroupName: !Ref GreenAutoScalingGroup
      PolicyType: TargetTrackingScaling
      EstimatedInstanceWarmup: 1100
      TargetTrackingConfiguration:
        PredefinedMetricSpecification:
          PredefinedMetricType: ASGAverageCPUUtilization
        TargetValue: 50

  GreenASGLifeCycleHook:
    Type: AWS::AutoScaling::LifecycleHook
    Condition: CreateGreenASG
    Properties:
      AutoScalingGroupName: !Ref GreenAutoScalingGroup
      DefaultResult: CONTINUE
      HeartbeatTimeout: 600
      LifecycleHookName: RemoveFromDomainHook
      LifecycleTransition: autoscaling:EC2_INSTANCE_TERMINATING


Outputs:
  BackupLoadBalancerDNSName:
    Description: The DNSName of the Staging Load Balancer
    Value: !GetAtt StagingElasticLoadBalancer.DNSName
    Condition: CreateStagingNLB