#
# KMS template used to create SSM keys for all environments.
# From: https://typicalrunt.me/2017/04/07/storing-secrets-with-aws-parameterstore/
#
#
#
AWSTemplateFormatVersion: "2010-09-09"
Description: "KMS key for secrets management (see Parameters for more info)"

Parameters:
  ENV:
    Type: String
    Default: dev
    AllowedValues:
    - dev
    - staging
    - prod

Resources:
  KmsKeyAlias:
    Type: "AWS::KMS::Alias"
    Properties:
      AliasName: !Sub "alias/${ENV}"
      TargetKeyId: !Ref KmsKey
  KmsKey:
    Type: "AWS::KMS::Key"
    Properties:
      Description: !Sub "Manages secrets in the ${ENV} namespace"
      Enabled: true
      EnableKeyRotation: true
      KeyPolicy:
        Version: "2012-10-17"
        Id: "KeyPolicyForKMS"
        Statement:
          - Sid: "Enable IAM User Permissions"
            Effect: "Allow"
            Principal:
              AWS: !Sub "arn:aws:iam::${AWS::AccountId}:root"
            Action: "kms:*"
            Resource: "*"

Outputs:
  KmsKeyId:
    Description: "ID of the KMS key"
    Value: !Ref KmsKey
    Export:
      Name: !Sub "kms:key:${ENV}:id"
  KmsKeyArn:
    Description: "ARN of the KMS key"
    Value: !GetAtt KmsKey.Arn
    Export:
      Name: !Sub "kms:key:${ENV}:arn"


#
# CloudFormation template for Node.js service on AWS Fargate.
#
#
# Example:
#  aws cloudformation deploy 
#    --stack-name dev-service 
#    --template-file cloudformation/service.yaml 
#    --parameter-overrides ENV=dev Vpc=vpc-XXX Subnets=subnet-XXX,subnet-XXX,subnet-XXX
#    --capabilities CAPABILITY_IAM
#

Description: >
  My Service

Parameters:

  ENV:
    Type: String
    Default: dev
    AllowedValues:
    - dev
    - staging
    - prod

  Vpc:
    Type: AWS::EC2::VPC::Id

  Subnets:
    Type: List<AWS::EC2::Subnet::Id>

  Repository:
    Type: String
    Default: my-service

  InstanceCount:
    Type: Number
    Default: 1

  HealthCheckPath:
    Type: String
    Default: /api/v1/liveness  # your service will need a healthcheck endpoint

Mappings:
  CertMap:
    Certificate:
      "dev": arn:aws:acm:us-east-1:XXX:certificate/XXX-XXX-XXX-XXX-XXXX
      "staging": arn:aws:acm:us-east-1:XXX:certificate/XXX-XXX-XXX-XXX-XXXX
      "prod": arn:aws:acm:us-east-1:XXX:certificate/XXX-XXX-XXX-XXX-XXXX
  Environment:
    NodeEnv:
      "dev": "development"
      "staging": "test"
      "prod": "production"

Resources:

  Cluster:
    Type: AWS::ECS::Cluster
    Properties:
      ClusterName: !Sub ${ENV}-service

  TaskIamRole:
    Type: AWS::IAM::Role
    Properties:
      Path: !Sub /service/${ENV}/
      AssumeRolePolicyDocument: |
        {
            "Statement": [{
                "Effect": "Allow",
                "Principal": { "Service": [ "ecs-tasks.amazonaws.com" ]},
                "Action": [ "sts:AssumeRole" ]
            }]
        }
      ManagedPolicyArns:
        - arn:aws:iam::aws:policy/service-role/AmazonECSTaskExecutionRolePolicy
      Policies:
        - PolicyName: "secrets-management"
          PolicyDocument:
            Version: "2012-10-17"
            Id: "AllowAccessToParameters"
            Statement:
              - Sid: "AllowAccessToGetParameters"
                Effect: "Allow"
                Action: 
                  - "ssm:GetParameters"
                  - "ssm:GetParametersByPath"
                Resource:
                  - !Sub "arn:aws:ssm:${AWS::Region}:${AWS::AccountId}:parameter/service/${ENV}/*"
              - Sid: "AllowAccessToDecryptParameters"
                Effect: "Allow"
                Action: "kms:Decrypt"
                Resource:
                  - Fn::ImportValue:
                      !Sub "kms:key:${ENV}:arn"

  LoadBalancerSecurityGroup:
    Type: "AWS::EC2::SecurityGroup"
    Properties:
      GroupDescription: !Sub ${ENV}-service
      SecurityGroupIngress:
        - CidrIp: "0.0.0.0/0"
          IpProtocol: "TCP"
          FromPort: 443
          ToPort: 443
      VpcId: !Ref Vpc

  ServiceSecurityGroup:
    Type: AWS::EC2::SecurityGroup
    Properties:
      GroupDescription: !Sub ${ENV}-service
      SecurityGroupIngress:
      - IpProtocol: tcp
        FromPort: 3000  # node.js running on port 3000 in this example
        ToPort: 3000
        SourceSecurityGroupId: !Ref LoadBalancerSecurityGroup
      VpcId: !Ref Vpc
      Tags:
        - Key: Name
          Value: !Sub ${ENV}-service

  LoadBalancer:
    Type: AWS::ElasticLoadBalancingV2::LoadBalancer
    Properties:
      Name: !Sub ${ENV}-service
      Subnets: !Ref Subnets
      SecurityGroups:
        - !Ref LoadBalancerSecurityGroup

  TargetGroup:
    Type: AWS::ElasticLoadBalancingV2::TargetGroup
    Properties:
      Name: !Sub ${ENV}-service
      VpcId: !Ref Vpc
      TargetType: ip
      Port: 3000
      Protocol: HTTP
      Matcher:
        HttpCode: 200-299
      HealthCheckIntervalSeconds: 60
      HealthCheckPath: !Ref HealthCheckPath
      HealthCheckProtocol: HTTP
      HealthCheckTimeoutSeconds: 5
      HealthyThresholdCount: 2
      TargetGroupAttributes:
        - Key: deregistration_delay.timeout_seconds
          Value: 30
      Tags:
        - Key: Name
          Value: !Sub ${ENV}-service

  LoadBalancerListener:
    Type: AWS::ElasticLoadBalancingV2::Listener
    Properties:
      LoadBalancerArn: !Ref LoadBalancer
      Certificates: 
        - CertificateArn: !FindInMap [CertMap, "Certificate", !Ref ENV]
      Port: 443
      Protocol: HTTPS
      DefaultActions:
      - Type: forward
        TargetGroupArn:
          Ref: TargetGroup
  
  ListenerRule:
    Type: AWS::ElasticLoadBalancingV2::ListenerRule
    Properties:
      Actions:
        - Type: forward
          TargetGroupArn: !Ref TargetGroup
      Conditions:
        - Field: path-pattern
          Values:
          - "*"
      ListenerArn: !Ref LoadBalancerListener
      Priority: 1

  Service:
    Type: AWS::ECS::Service
    DependsOn: 
      - LoadBalancerListener
    Properties:
      ServiceName: !Sub ${ENV}-service
      Cluster: !Ref Cluster
      DesiredCount: !Ref InstanceCount
      LaunchType: FARGATE
      TaskDefinition: !Ref TaskDefinition
      DeploymentConfiguration: 
        MaximumPercent: 200
        MinimumHealthyPercent: 50
      LoadBalancers:
        - ContainerName: !Sub ${ENV}-service
          ContainerPort: 3000
          TargetGroupArn: !Ref TargetGroup
      NetworkConfiguration:
        AwsvpcConfiguration:
          AssignPublicIp: ENABLED  ## fixme Required for non-Nat'd deployments?
          SecurityGroups:
            - !GetAtt ServiceSecurityGroup.GroupId
          Subnets: !Ref Subnets

  TaskDefinition:
    Type: AWS::ECS::TaskDefinition
    Properties:
      Cpu: 256
      Memory: 512
      NetworkMode: awsvpc
      RequiresCompatibilities:
       - FARGATE
      ExecutionRoleArn: !GetAtt TaskIamRole.Arn
      TaskRoleArn: !GetAtt TaskIamRole.Arn
      ContainerDefinitions:
        - Name: !Sub ${ENV}-service
          Image: !Sub ${AWS::AccountId}.dkr.ecr.${AWS::Region}.amazonaws.com/${Repository}:${ENV}-latest
          Essential: true
          Memory: 512
          PortMappings:
            - ContainerPort: 3000
          Environment:
            - Name: ENV
              Value: !Sub ${ENV}
            - Name: NODE_ENV
              Value:  !FindInMap [Environment, "NodeEnv", !Ref ENV]
          LogConfiguration:
            LogDriver: awslogs
            Options:
              awslogs-group: !Ref LogGroup
              awslogs-region: us-east-1
              awslogs-stream-prefix: !Sub ${ENV}-service

  LogGroup:
    Type: AWS::Logs::LogGroup
    Properties:
      LogGroupName: !Sub ${ENV}-service
      RetentionInDays: 30

Outputs:
  Cluster:
    Value: !Ref Cluster


#!/bin/sh
#
# Get all system parameters from AWS SSM and store into the current environment
#
# Run node process
#

echo "*************************"
echo " Env: ${ENV:-dev}"
echo "*************************"

json=$(aws ssm get-parameters-by-path --path "/${SERVICE:-service}/${ENV:-dev}/" --recursive --with-decryption)

params=$(echo $json | jq -r '.Parameters[] | [.Name, .Value] | join("=")')
for param in $params
do
  export ${param##/${SERVICE:-service}/${ENV:-dev}/}
done
export -p
node server.js

#
# Dockerfile
#
FROM node:9
WORKDIR /app
COPY package.json /app
RUN npm install
RUN apt-get update --yes
RUN apt-get install jq --yes --quiet
RUN apt-get install python-pip python-dev build-essential --yes --quiet
RUN pip install awscli --upgrade
COPY . /app
CMD /app/boot.sh
EXPOSE 3000