def _construct_lambda_layer()

in samtranslator/model/sam_resources.py [0:0]

• 40 lines of code
• 12 McCabe index (conditional complexity)

    def _construct_lambda_layer(self, intrinsics_resolver: IntrinsicsResolver) -> LambdaLayerVersion:
        """Constructs and returns the Lambda function.

        :returns: a list containing the Lambda function and execution role resources
        :rtype: list
        """
        # Resolve intrinsics if applicable:
        self.LayerName = resolve_string_parameter_in_resource(
            self.logical_id, intrinsics_resolver, self.LayerName, "LayerName"
        )
        self.LicenseInfo = resolve_string_parameter_in_resource(
            self.logical_id, intrinsics_resolver, self.LicenseInfo, "LicenseInfo"
        )
        self.Description = resolve_string_parameter_in_resource(
            self.logical_id, intrinsics_resolver, self.Description, "Description"
        )
        self.RetentionPolicy = resolve_string_parameter_in_resource(
            self.logical_id, intrinsics_resolver, self.RetentionPolicy, "RetentionPolicy"
        )

        # If nothing defined, this will be set to Retain
        retention_policy_value = self._get_retention_policy_value()

        attributes = self.get_passthrough_resource_attributes()
        if "DeletionPolicy" not in attributes:
            attributes["DeletionPolicy"] = self.RETAIN
        if retention_policy_value is not None:
            attributes["DeletionPolicy"] = retention_policy_value

        old_logical_id = self.logical_id

        # This is to prevent the passthrough resource attributes to be included for hashing
        hash_dict = copy.deepcopy(self.to_dict())
        if "DeletionPolicy" in hash_dict.get(old_logical_id, {}):
            del hash_dict[old_logical_id]["DeletionPolicy"]
        if "UpdateReplacePolicy" in hash_dict.get(old_logical_id, {}):
            del hash_dict[old_logical_id]["UpdateReplacePolicy"]
        if "Metadata" in hash_dict.get(old_logical_id, {}):
            del hash_dict[old_logical_id]["Metadata"]

        new_logical_id = logical_id_generator.LogicalIdGenerator(old_logical_id, hash_dict).gen()
        self.logical_id = new_logical_id

        lambda_layer = LambdaLayerVersion(self.logical_id, depends_on=self.depends_on, attributes=attributes)

        # Changing the LayerName property: when a layer is published, it is given an Arn
        # example: arn:aws:lambda:us-west-2:123456789012:layer:MyLayer:1
        # where MyLayer is the LayerName property if it exists; otherwise, it is the
        # LogicalId of this resource. Since a LayerVersion is an immutable resource, when
        # CloudFormation updates this resource, it will ALWAYS create a new version then
        # delete the old version if the logical ids match. What this does is change the
        # logical id of every layer (so a `DeletionPolicy: Retain` can work) and set the
        # LayerName property of the layer so that the Arn will still always be the same
        # with the exception of an incrementing version number.
        if not self.LayerName:
            self.LayerName = old_logical_id

        lambda_layer.LayerName = self.LayerName
        lambda_layer.Description = self.Description
        lambda_layer.Content = construct_s3_location_object(self.ContentUri, self.logical_id, "ContentUri")

        lambda_layer.CompatibleArchitectures = self.CompatibleArchitectures
        self._validate_architectures(lambda_layer)
        lambda_layer.CompatibleRuntimes = self.CompatibleRuntimes
        lambda_layer.LicenseInfo = self.LicenseInfo

        return lambda_layer