def _construct_version(self, function, intrinsics_resolver):
"""Constructs a Lambda Version resource that will be auto-published when CodeUri of the function changes.
Old versions will not be deleted without a direct reference from the CloudFormation template.
:param model.lambda_.LambdaFunction function: Lambda function object that is being connected to a version
:param model.intrinsics.resolver.IntrinsicsResolver intrinsics_resolver: Class that can help resolve
references to parameters present in CodeUri. It is a common usecase to set S3Key of Code to be a
template parameter. Need to resolve the values otherwise we will never detect a change in Code dict
:return: Lambda function Version resource
"""
code_dict = function.Code
if not code_dict:
raise ValueError(
"Lambda function code must be a valid non-empty dictionary")
if not intrinsics_resolver:
raise ValueError(
"intrinsics_resolver is required for versions creation")
# Resolve references to template parameters before creating hash. This will *not* resolve all intrinsics
# because we cannot resolve runtime values like Arn of a resource. For purposes of detecting changes, this
# is good enough. Here is why:
#
# When using intrinsic functions there are two cases when has must change:
# - Value of the template parameter changes
# - (or) LogicalId of a referenced resource changes ie. !GetAtt NewResource.Arn
#
# Later case will already change the hash because some value in the Code dictionary changes. We handle the
# first case by resolving references to template parameters. It is okay even if these references are
# present inside another intrinsic such as !Join. The resolver will replace the reference with the parameter's
# value and keep all other parts of !Join identical. This will still trigger a change in the hash.
code_dict = intrinsics_resolver.resolve_parameter_refs(code_dict)
# Construct the LogicalID of Lambda version by appending 10 characters of SHA of CodeUri. This is necessary
# to trigger creation of a new version every time code location changes. Since logicalId changes, CloudFormation
# will drop the old version and create a new one for us. We set a DeletionPolicy on the version resource to
# prevent CloudFormation from actually deleting the underlying version resource
#
# SHA Collisions: For purposes of triggering a new update, we are concerned about just the difference previous
# and next hashes. The chances that two subsequent hashes collide is fairly low.
prefix = "{id}Version".format(id=self.logical_id)
logical_id = logical_id_generator.LogicalIdGenerator(
prefix, code_dict).gen()
attributes = self.get_passthrough_resource_attributes()
if attributes is None:
attributes = {}
attributes["DeletionPolicy"] = "Retain"
lambda_version = LambdaVersion(logical_id=logical_id,
attributes=attributes)
lambda_version.FunctionName = function.get_runtime_attr('name')
lambda_version.Description = self.VersionDescription
return lambda_version
def _construct_version(self, function, intrinsics_resolver):
"""Constructs a Lambda Version resource that will be auto-published when CodeUri of the function changes.
Old versions will not be deleted without a direct reference from the CloudFormation template.
:param model.lambda_.LambdaFunction function: Lambda function object that is being connected to a version
:param model.intrinsics.resolver.IntrinsicsResolver intrinsics_resolver: Class that can help resolve
references to parameters present in CodeUri. It is a common usecase to set S3Key of Code to be a
template parameter. Need to resolve the values otherwise we will never detect a change in Code dict
:return: Lambda function Version resource
"""
code_dict = function.Code
if not code_dict:
raise ValueError("Lambda function code must be a valid non-empty dictionary")
if not intrinsics_resolver:
raise ValueError("intrinsics_resolver is required for versions creation")
# Resolve references to template parameters before creating hash. This will *not* resolve all intrinsics
# because we cannot resolve runtime values like Arn of a resource. For purposes of detecting changes, this
# is good enough. Here is why:
#
# When using intrinsic functions there are two cases when has must change:
# - Value of the template parameter changes
# - (or) LogicalId of a referenced resource changes ie. !GetAtt NewResource.Arn
#
# Later case will already change the hash because some value in the Code dictionary changes. We handle the
# first case by resolving references to template parameters. It is okay even if these references are
# present inside another intrinsic such as !Join. The resolver will replace the reference with the parameter's
# value and keep all other parts of !Join identical. This will still trigger a change in the hash.
code_dict = intrinsics_resolver.resolve_parameter_refs(code_dict)
# Construct the LogicalID of Lambda version by appending 10 characters of SHA of CodeUri. This is necessary
# to trigger creation of a new version every time code location changes. Since logicalId changes, CloudFormation
# will drop the old version and create a new one for us. We set a DeletionPolicy on the version resource to
# prevent CloudFormation from actually deleting the underlying version resource
#
# SHA Collisions: For purposes of triggering a new update, we are concerned about just the difference previous
# and next hashes. The chances that two subsequent hashes collide is fairly low.
prefix = "{id}Version".format(id=self.logical_id)
logical_id = logical_id_generator.LogicalIdGenerator(prefix, code_dict).gen()
attributes = self.get_passthrough_resource_attributes()
if attributes is None:
attributes = {}
attributes["DeletionPolicy"] = "Retain"
lambda_version = LambdaVersion(logical_id=logical_id, attributes=attributes)
lambda_version.FunctionName = function.get_runtime_attr('name')
lambda_version.Description = self.VersionDescription
return lambda_version
def _make_lambda_version(self, logical_id, func):
version = LambdaVersion(logical_id)
version.FunctionName = {"Ref": func.logical_id}
return version
def _make_lambda_version(self, logical_id, func):
version = LambdaVersion(logical_id)
version.FunctionName = {"Ref": func.logical_id}
return version