# ###################################
##       Rule Specification        ##
#####################################
# 
# Rule Identifier:
#   ec2_launch_template_monitoring_enabled_check
# 
# Description:
#   This control checks whether the Amazon EC2 launch template has detailed monitoring enabled.
# 
# Reports on:
#   AWS::EC2::LaunchTemplate
# 
# Evaluates:
#   AWS CloudFormation, AWS CloudFormation hook
# 
# Rule Parameters:
#   None
# 
# Scenarios:
#   Scenario: 1
#      Given: The input document is an AWS CloudFormation or CloudFormation hook document
#        And: The input document does not contain any EC2 launch template resources
#       Then: SKIP
#   Scenario: 2
#      Given: The input document is an AWS CloudFormation or CloudFormation hook document
#        And: The input document contains an EC2 launch template resource
#        And: 'LaunchTemplateData.Monitoring.Enabled' has not been provided or has been provided and is empty.
#       Then: FAIL
#   Scenario: 3
#      Given: The input document is an AWS CloudFormation or CloudFormation hook document
#        And: The input document contains an EC2 launch template resource
#        And: 'LaunchTemplateData.Monitoring.Enabled' has been provided
#        And: 'LaunchTemplateData.Monitoring.Enabled' is equal to a value other than bool(true)
#       Then: FAIL
#   Scenario: 4
#      Given: The input document is an AWS CloudFormation or CloudFormation hook document
#        And: The input document contains an EC2 launch template resource
#        And: 'LaunchTemplateData.Monitoring.Enabled' has been provided
#        And: 'LaunchTemplateData.Monitoring.Enabled' is equal to bool(true)
#       Then: PASS

#
# Constants
#
let EC2_LAUNCH_TEMPLATE_TYPE = "AWS::EC2::LaunchTemplate"
let INPUT_DOCUMENT = this

#
# Assignments
#
let ec2_launch_templates = Resources.*[ Type == %EC2_LAUNCH_TEMPLATE_TYPE ]

#
# Primary Rules
#
rule ec2_launch_template_monitoring_enabled_check when is_cfn_template(this)
                                                       %ec2_launch_templates not empty {
    check(%ec2_launch_templates.Properties)
        <<
        [CT.EC2.PR.10]: Require Amazon EC2 launch templates to have Amazon CloudWatch detailed monitoring activated
        [FIX]: In 'LaunchTemplateData', provide a 'Monitoring' configuration with 'Enabled' set to 'true'.
        >>
}

rule ec2_launch_template_monitoring_enabled_check when is_cfn_hook(%INPUT_DOCUMENT, %EC2_LAUNCH_TEMPLATE_TYPE) {
    check(%INPUT_DOCUMENT.%EC2_LAUNCH_TEMPLATE_TYPE.resourceProperties)
        <<
        [CT.EC2.PR.10]: Require Amazon EC2 launch templates to have Amazon CloudWatch detailed monitoring activated
        [FIX]: In 'LaunchTemplateData', provide a 'Monitoring' configuration with 'Enabled' set to 'true'.
        >>
}

#
# Parameterized Rules
#
rule check(ec2_launch_template) {
    %ec2_launch_template {
        # Scenario 2
        LaunchTemplateData exists
        LaunchTemplateData is_struct

        LaunchTemplateData {
            Monitoring exists
            Monitoring is_struct

            # Scenario 3 and 4
            Monitoring {
                Enabled exists
                Enabled == true
            }

        }
    }
}

#
# Utility Rules
#
rule is_cfn_template(doc) {
    %doc {
        AWSTemplateFormatVersion exists  or
        Resources exists
    }
}

rule is_cfn_hook(doc, RESOURCE_TYPE) {
    %doc.%RESOURCE_TYPE.resourceProperties exists
}