Parameters:
  DashboardImage:
    Type: String
    Description: Docker image url for dashboard lambda image

  MetricNamespace:
    Type: String
    Description: The CloudWatch metric namespace containing metrics

  MeshName:
    Type: String

  Name:
    Type: String

  Period:
    Type: Number
    Default: 60

  Start:
    Type: String
    Default: '-PT1H'

  MetricNameSanitizer:
    Type: String
    Default: ''

  VirtualNodes:
    Type: CommaDelimitedList
    Description: List of virtual nodes names this dashboard will display
    Default: ''

  VirtualGateway:
    Type: String
    Description: Virtual gateway name this dashboard will display
    Default: ''

Resources:
  
  LambdaExecutionRole:
    Type: AWS::IAM::Role
    Properties:
      Path: /
      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
        - arn:aws:iam::aws:policy/AWSAppMeshReadOnly
      Policies:
        - PolicyName: CreateDeleteDashboardPolicy
          PolicyDocument:
            Version: '2012-10-17'
            Statement:
              - Effect: Allow
                Action:
                  - cloudwatch:PutDashboard
                  - cloudwatch:DeleteDashboards
                  - cloudwatch:GetDashboard
                Resource: '*'

  MetricsExtensionDashboard:
    Type: Custom::DashboardGenerator
    Properties:
      ServiceToken: !GetAtt DashboardGeneratorFunction.Arn
      MetricNamespace: !Ref MetricNamespace
      MeshName: !Ref MeshName
      Name: !Ref Name
      Period: !Ref Period
      Start: !Ref Start
      MetricNameSanitizer: !Ref MetricNameSanitizer
      VirtualNodes: !Join [ ',', !Ref VirtualNodes ] 
      VirtualGateway: !Ref VirtualGateway
      Region: !Ref AWS::Region

  DashboardGeneratorFunction:
    Type: AWS::Lambda::Function
    Properties:
      PackageType: Image
      Timeout: 300
      Role: !GetAtt LambdaExecutionRole.Arn
      Code:
        ImageUri: !Ref DashboardImage