AWSTemplateFormatVersion: "2010-09-09"
Description: Factorio Spot Price Server via Docker / ECS
Parameters:

  ECSAMI:
    Description: AWS ECS AMI ID
    Type: AWS::SSM::Parameter::Value<AWS::EC2::Image::Id>
    Default: /aws/service/ecs/optimized-ami/amazon-linux-2/recommended/image_id

  FactorioImageTag:
    Type: String
    Description: "(Examples include latest, stable, 0.17, 0.17.33) Refer to tag descriptions available here: https://hub.docker.com/r/factoriotools/factorio/)"
    Default: latest

  ServerState:
    Type: String
    Description: "Running: A spot instance will launch shortly after setting this parameter. Stopped: Your spot instance will be terminated shortly after setting this parameter."
    Default: Running
    AllowedValues: 
    - Running
    - Stopped

  InstanceType:
    Type: String
    Description: "m3.medium is a good cost effective (albeit older) instance, 1 VCPU and 3.75 GB of RAM with moderate network performance. Change at your discretion. https://aws.amazon.com/ec2/instance-types/."
    Default: m3.medium

  SpotPrice:
    Type: String
    Description: "An m3.medium shouldn't cost more than a cent per hour. Note: Leave this blank to use on-demand pricing."
    Default: "0.05"

  KeyPairName:
    Type: AWS::EC2::KeyPair::KeyName
    Description: (Optional - An empty value disables this feature)
    Default: ''

  YourIp:
    Type: String
    Description: (Optional - An empty value disables this feature)
    Default: ''

  HostedZoneId:
    Type: String
    Description: (Optional - An empty value disables this feature) If you have a hosted zone in Route 53 and wish to set a DNS record whenever your Factorio instance starts, supply the hosted zone ID here.
    Default: ''

  RecordName:
    Type: String
    Description: (Optional - An empty value disables this feature) If you have a hosted zone in Route 53 and wish to set a DNS record whenever your Factorio instance starts, supply the name of the record here (e.g. factorio.mydomain.com).
    Default: ''

  EnableRcon:
    Type: String
    Description: Refer to https://hub.docker.com/r/factoriotools/factorio/ for further RCON configuration details. This parameter simply opens / closes the port on the security group.
    Default: false
    AllowedValues:
    - true
    - false

Metadata:
  AWS::CloudFormation::Interface:
    ParameterGroups:
      - Label: 
          default: Essential Configuration
        Parameters:
        - FactorioImageTag
        - ServerState
        - InstanceType
        - SpotPrice
        - EnableRcon
      - Label: 
          default: Remote Access (SSH) Configuration (Optional)
        Parameters:
        - KeyPairName
        - YourIp
      - Label: 
          default: DNS Configuration (Optional)
        Parameters:
        - HostedZoneId
        - RecordName
    ParameterLabels:
      FactorioImageTag:
        default: "Which version of Factorio do you want to launch?"
      ServerState:
        default: "Update this parameter to shut down / start up your Factorio server as required to save on cost. Takes a few minutes to take effect."
      InstanceType:
        default: "Which instance type?"
      SpotPrice:
        default: "Maximum spot price per hour? Leave blank to disable spot pricing."
      KeyPairName:
        default: "If you wish to access the instance via SSH, select a Key Pair to use."
      YourIp:
        default: "If you wish to access the instance via SSH, provide your public IP address."
      HostedZoneId:
        default: "If you have a hosted zone in Route 53 and wish to update a DNS record whenever your Factorio instance starts, supply the hosted zone ID here."
      RecordName:
        default: "If you have a hosted zone in Route 53 and wish to set a DNS record whenever your Factorio instance starts, supply a record name here (e.g. factorio.mydomain.com)."
      EnableRcon:
        default: "Do you wish to enable RCON?"

Conditions:
  KeyPairNameProvided: !Not [ !Equals [ !Ref KeyPairName, '' ] ]
  IpAddressProvided: !Not [ !Equals [ !Ref YourIp, '' ] ]
  DnsConfigEnabled: !And [ !Not [ !Equals [ !Ref HostedZoneId, '' ] ], !Not [ !Equals [ !Ref RecordName, '' ] ] ]
  SpotPriceProvided: !Not [ !Equals [ !Ref SpotPrice, '' ] ]
  DoEnableRcon: !Equals [ !Ref EnableRcon, 'true' ]


Mappings:
  ServerState:
    Running:
      AutoScalingCapacity: 1
    Stopped:
      AutoScalingCapacity: 0
    

Resources:

  # ====================================================
  # BASIC VPC
  # ====================================================

  Vpc: 
    Type: AWS::EC2::VPC
    Properties: 
      CidrBlock: 10.100.0.0/26
      EnableDnsSupport: true
      EnableDnsHostnames: true

  SubnetA:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: !Select 
      - 0
      - !GetAZs 
        Ref: 'AWS::Region'
      CidrBlock: !Select [ 0, !Cidr [ 10.100.0.0/26, 4, 4 ] ]
      VpcId: !Ref Vpc  

  SubnetARoute:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties: 
      RouteTableId: !Ref RouteTable
      SubnetId: !Ref SubnetA

  SubnetBRoute:
    Type: AWS::EC2::SubnetRouteTableAssociation
    Properties: 
      RouteTableId: !Ref RouteTable
      SubnetId: !Ref SubnetB  

  SubnetB:
    Type: AWS::EC2::Subnet
    Properties:
      AvailabilityZone: !Select 
      - 1
      - !GetAZs 
        Ref: 'AWS::Region'
      CidrBlock: !Select [ 1, !Cidr [ 10.100.0.0/26, 4, 4 ] ]
      VpcId: !Ref Vpc

  InternetGateway:
    Type: AWS::EC2::InternetGateway
    Properties: {}

  InternetGatewayAttachment:
    Type: AWS::EC2::VPCGatewayAttachment
    Properties: 
      InternetGatewayId: !Ref InternetGateway
      VpcId: !Ref Vpc

  RouteTable:
    Type: AWS::EC2::RouteTable
    Properties: 
      VpcId: !Ref Vpc    

  Route:
    Type: AWS::EC2::Route
    Properties: 
      DestinationCidrBlock: 0.0.0.0/0
      GatewayId: !Ref InternetGateway
      RouteTableId: !Ref RouteTable

  # ====================================================
  # EFS FOR PERSISTENT DATA
  # ====================================================

  Efs:
    Type: AWS::EFS::FileSystem
    Properties: {}

  MountA:
    Type: AWS::EFS::MountTarget
    Properties:
      FileSystemId: !Ref Efs
      SecurityGroups:
      - !Ref EfsSg
      SubnetId: !Ref SubnetA

  MountB:
    Type: AWS::EFS::MountTarget
    Properties:
      FileSystemId: !Ref Efs
      SecurityGroups:
      - !Ref EfsSg
      SubnetId: !Ref SubnetB

  EfsSg:
    Type: AWS::EC2::SecurityGroup
    Properties: 
      GroupName: factorio-efs
      GroupDescription: factorio-efs
      SecurityGroupIngress:
      - FromPort: 2049
        ToPort: 2049
        IpProtocol: tcp
        SourceSecurityGroupId: !Ref Ec2Sg
      VpcId: !Ref Vpc
      
  # ====================================================
  # INSTANCE CONFIG
  # ====================================================

  Ec2Sg:
    Type: AWS::EC2::SecurityGroup
    Properties: 
      GroupName: factorio-ec2
      GroupDescription: factorio-ec2
      SecurityGroupIngress:
      - !If
        - IpAddressProvided 
        - FromPort: 22
          ToPort: 22
          IpProtocol: tcp
          CidrIp: !Sub "${YourIp}/32"
        - !Ref 'AWS::NoValue'
      - FromPort: 34197
        ToPort: 34197
        IpProtocol: udp
        CidrIp: 0.0.0.0/0
      - !If
        - DoEnableRcon
        - FromPort: 27015
          ToPort: 27015
          IpProtocol: tcp
          CidrIp: 0.0.0.0/0
        - !Ref 'AWS::NoValue'
      VpcId: !Ref Vpc

  LaunchConfiguration:
    Type: AWS::AutoScaling::LaunchConfiguration
    Properties:
      AssociatePublicIpAddress: true
      IamInstanceProfile: !Ref InstanceProfile
      ImageId: !Ref ECSAMI
      InstanceType: !Ref InstanceType
      KeyName: 
        !If [ KeyPairNameProvided, !Ref KeyPairName, !Ref 'AWS::NoValue' ]
      SecurityGroups:
      - !Ref Ec2Sg
      SpotPrice: !If [ SpotPriceProvided, !Ref SpotPrice, !Ref 'AWS::NoValue' ]
      UserData:
        Fn::Base64: !Sub |
          #!/bin/bash -xe
          yum install -y amazon-efs-utils
          mkdir /opt/factorio
          mount -t efs ${Efs}:/ /opt/factorio
          chown 845:845 /opt/factorio
          echo ECS_CLUSTER=${EcsCluster} >> /etc/ecs/ecs.config          

  AutoScalingGroup:
    Type: AWS::AutoScaling::AutoScalingGroup
    DependsOn:
    - MountA
    - MountB
    Properties:
      AutoScalingGroupName: factorio
      DesiredCapacity: !FindInMap [ ServerState, !Ref ServerState, AutoScalingCapacity ]
      LaunchConfigurationName: !Ref LaunchConfiguration
      MaxSize: !FindInMap [ ServerState, !Ref ServerState, AutoScalingCapacity ]
      MinSize: !FindInMap [ ServerState, !Ref ServerState, AutoScalingCapacity ]
      VPCZoneIdentifier:
        - !Ref SubnetA
        - !Ref SubnetB

  InstanceRole:
    Type: AWS::IAM::Role
    Properties: 
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
        - Effect: Allow
          Principal:
            Service:
            - ec2.amazonaws.com
          Action:
          - sts:AssumeRole
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AmazonEC2ContainerServiceforEC2Role
      Policies:
        - PolicyName: root
          PolicyDocument: 
            Version: "2012-10-17"
            Statement: 
              - Effect: "Allow"
                Action: "route53:*"
                Resource: "*"

  InstanceProfile:
    Type: AWS::IAM::InstanceProfile
    Properties: 
      Roles:
        - !Ref InstanceRole

  EcsCluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: factorio

  EcsService:
    Type: AWS::ECS::Service
    Properties: 
      Cluster: !Ref EcsCluster
      DesiredCount: 1
      ServiceName: factorio
      TaskDefinition: !Ref EcsTask  
      DeploymentConfiguration:
        MaximumPercent: 100
        MinimumHealthyPercent: 0

  EcsTask:
    Type: AWS::ECS::TaskDefinition
    Properties: 
      Volumes:
      - Host:
          SourcePath: /opt/factorio
        Name: factorio
      ContainerDefinitions:      
        - Name: factorio
          MemoryReservation: 1024
          Image: !Sub "factoriotools/factorio:${FactorioImageTag}"
          PortMappings:
          - ContainerPort: 34197
            HostPort: 34197
            Protocol: udp
          - ContainerPort: 27015
            HostPort: 27015
            Protocol: tcp
          MountPoints:
          - ContainerPath: /factorio
            SourceVolume: factorio
            ReadOnly: false

  # ====================================================
  # SET DNS RECORD
  # ====================================================

  SetDNSRecordLambdaRole:
    Type: AWS::IAM::Role
    Condition: DnsConfigEnabled
    Properties: 
      AssumeRolePolicyDocument:
        Version: '2012-10-17'
        Statement:
        - Effect: Allow
          Principal:
            Service:
            - lambda.amazonaws.com
          Action:
          - sts:AssumeRole
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
      Policies:
        - PolicyName: root
          PolicyDocument: 
            Version: "2012-10-17"
            Statement: 
              - Effect: "Allow"
                Action: "route53:*"
                Resource: "*"
              - Effect: "Allow"
                Action: "ec2:DescribeInstance*"
                Resource: "*"

  SetDNSRecordLambda:
    Type: "AWS::Lambda::Function"
    Condition: DnsConfigEnabled
    Properties: 
      Environment:
        Variables:
          HostedZoneId: !Ref HostedZoneId
          RecordName: !Ref RecordName
      Code:
        ZipFile: |
          import boto3
          import os
          def handler(event, context):
            new_instance = boto3.resource('ec2').Instance(event['detail']['EC2InstanceId'])
            boto3.client('route53').change_resource_record_sets(
              HostedZoneId= os.environ['HostedZoneId'],
              ChangeBatch={
                  'Comment': 'updating',
                  'Changes': [
                      {
                          'Action': 'UPSERT',
                          'ResourceRecordSet': {
                              'Name': os.environ['RecordName'],
                              'Type': 'A',
                              'TTL': 60,
                              'ResourceRecords': [
                                  {
                                      'Value': new_instance.public_ip_address
                                  },
                              ]
                          }
                      },
                  ]
              })
      Description: Sets Route 53 DNS Record for Factorio
      FunctionName: factorio-set-dns
      Handler: index.handler
      MemorySize: 128
      Role: !GetAtt SetDNSRecordLambdaRole.Arn
      Runtime: python3.7
      Timeout: 20

  LaunchEvent:
    Type: AWS::Events::Rule
    Condition: DnsConfigEnabled
    Properties: 
      EventPattern:
        source:
        - aws.autoscaling
        detail-type:
        - EC2 Instance Launch Successful
        detail:
          AutoScalingGroupName:
          - !Ref AutoScalingGroup
      Name: Factorio-Instance-Launch
      State: ENABLED
      Targets:
        - Arn: !GetAtt SetDNSRecordLambda.Arn
          Id: factorio-set-dns

  LaunchEventLambdaPermission:
    Type: AWS::Lambda::Permission
    Condition: DnsConfigEnabled
    Properties: 
      Action: lambda:InvokeFunction
      FunctionName: !GetAtt SetDNSRecordLambda.Arn
      Principal: events.amazonaws.com
      SourceArn: !GetAtt LaunchEvent.Arn

Outputs:
  CheckInstanceIp:
    Description: To find your Factorio instance IP address, visit the following link. Click on the instance to find its Public IP address.
    Value: !Sub "https://${AWS::Region}.console.aws.amazon.com/ec2/v2/home?region=${AWS::Region}#Instances:tag:aws:autoscaling:groupName=${AutoScalingGroup};sort=tag:Name"