# ###################################
##       Rule Specification        ##
#####################################
# 
# Rule Identifier:
#   sagemaker_notebook_instance_root_access_check
# 
# Description:
#   This control checks whether Amazon SageMaker notebook instances allow root access.
# 
# Reports on:
#   AWS::SageMaker::NotebookInstance
# 
# 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 SageMaker notebook instance resources
#      Then: SKIP
#   Scenario: 2
#     Given: The input document is an AWS CloudFormation or CloudFormation hook document
#       And: The input document contains a SageMaker notebook instance resource
#       And: 'RootAccess' has not been provided
#      Then: FAIL
#   Scenario: 3
#     Given: The input document is an AWS CloudFormation or CloudFormation hook document
#       And: The input document contains a SageMaker notebook instance resource
#       And: 'RootAccess' has been provided and is set to a value other than 'Disabled'
#      Then: FAIL
#   Scenario: 4
#     Given: The input document is an AWS CloudFormation or CloudFormation hook document
#       And: The input document contains a SageMaker notebook instance resource
#       And: 'RootAccess' has been provided and is set to 'Disabled'
#      Then: PASS

#
# Constants
#
let SAGEMAKER_NOTEBOOK_INSTANCE_TYPE = "AWS::SageMaker::NotebookInstance"
let INPUT_DOCUMENT = this

#
# Assignments
#
let sagemaker_notebook_instances = Resources.*[ Type == %SAGEMAKER_NOTEBOOK_INSTANCE_TYPE ]

#
# Primary Rules
#
rule sagemaker_notebook_instance_root_access_check when is_cfn_template(%INPUT_DOCUMENT)
                                                        %sagemaker_notebook_instances not empty {
    check(%sagemaker_notebook_instances.Properties)
        <<
        [CT.SAGEMAKER.PR.3]: Require Amazon SageMaker notebook instances to have root access disallowed
        [FIX]: Set 'RootAccess' to 'Disabled'.
        >>
}

rule sagemaker_notebook_instance_root_access_check when is_cfn_hook(%INPUT_DOCUMENT, %SAGEMAKER_NOTEBOOK_INSTANCE_TYPE) {
    check(%INPUT_DOCUMENT.%SAGEMAKER_NOTEBOOK_INSTANCE_TYPE.resourceProperties)
        <<
        [CT.SAGEMAKER.PR.3]: Require Amazon SageMaker notebook instances to have root access disallowed
        [FIX]: Set 'RootAccess' to 'Disabled'.
        >>
}

rule check(sagemaker_notebook_instance) {
    %sagemaker_notebook_instance {
        # Scenarios 2, 3 and 4
        RootAccess exists
        RootAccess == "Disabled"
    }
}

#
# 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
}