def patch_botocore(self):
"""Context manager that will patch botocore to use Localstack.
Since boto3 relies on botocore to perform API calls, this method
also effectively patches boto3.
"""
logger.debug("enter patch")
try:
factory = self
patches = []
# Step 1: patch botocore Session to use Localstack.
attr = {}
@property
def localstack_session(self):
# Simlate the 'localstack_session' attr from Session class below.
# Patch this into the botocore Session class.
if "localstack_session" in self.__dict__:
# We're patching this into the base botocore Session,
# but we don't want to override things for the Session
# subclass below.
return self.__dict__["localstack_session"]
return factory.localstack_session
@localstack_session.setter
def localstack_session(self, value):
assert isinstance(self, Session)
self.__dict__["localstack_session"] = value
attr["localstack_session"] = localstack_session
@property
def _components(self):
if isinstance(self, Session):
try:
return self.__dict__["_components"]
except KeyError:
raise AttributeError("_components")
proxy_components = botocore.session.Session._proxy_components
if self not in proxy_components:
proxy_components[self] = botocore.session.ComponentLocator(
)
self._register_components()
return proxy_components[self]
@_components.setter
def _components(self, value):
self.__dict__["_components"] = value
@property
def _internal_components(self):
if isinstance(self, Session):
try:
return self.__dict__["_internal_components"]
except KeyError:
raise AttributeError("_internal_components")
proxy_components = botocore.session.Session._proxy_components
if self not in proxy_components:
proxy_components[self] = DebugComponentLocator()
self._register_components()
return proxy_components[self]
@_internal_components.setter
def _internal_components(self, value):
self.__dict__["_internal_components"] = value
attr.update({
"_components": _components,
"_internal_components": _internal_components,
"_proxy_components": weakref.WeakKeyDictionary(),
})
@property
def _credentials(self):
return self._proxy_credentials.get(self)
@_credentials.setter
def _credentials(self, value):
self._proxy_credentials[self] = value
attr.update({
"_credentials": _credentials,
"_proxy_credentials": weakref.WeakKeyDictionary(),
})
patches.append(
mock.patch.multiple("botocore.session.Session",
create=True,
**attr))
patches.append(
mock.patch.multiple(
botocore.session.Session,
_register_endpoint_resolver=utils.unbind(
Session._register_endpoint_resolver),
_register_credential_provider=utils.unbind(
Session._register_credential_provider),
create_client=utils.unbind(Session.create_client),
))
# Step 2: Safety checks
# Make absolutly sure we use Localstack and not AWS.
_original_convert_to_request_dict = (
botocore.client.BaseClient._convert_to_request_dict)
@functools.wraps(_original_convert_to_request_dict)
def _convert_to_request_dict(self, *args, **kwargs):
request_dict = _original_convert_to_request_dict(
self, *args, **kwargs)
assert factory.localstack_session.hostname in request_dict[
"url"]
return request_dict
patches.append(
mock.patch(
"botocore.client.BaseClient._convert_to_request_dict",
_convert_to_request_dict,
))
# Step 3: Patch existing clients
# Patching botocore Session doesn't help with an existing
# botocore Clients objects. They will have already been created with
# endpoints aimed at AWS. We need to patch botocore.client.BaseClient
# to temporarially act like a Localstack.
original_init = botocore.client.BaseClient.__init__
@functools.wraps(original_init)
def new_init(self, *args, **kwargs):
# Every client created during the patch is a Localstack client.
# Set this flag so that the proxy_client_attr() stuff below
# won't break during original_init().
self._is_pytest_localstack = True
original_init(self, *args, **kwargs)
patches.append(
mock.patch.multiple(botocore.client.BaseClient,
__init__=new_init))
# Create a place to store proxy clients.
patches.append(
mock.patch(
"botocore.client.BaseClient._proxy_clients",
weakref.WeakKeyDictionary(),
create=True,
))
def new_getattribute(self, key):
if key.startswith("__"):
return object.__getattribute__(self, key)
proxied_keys = [
"_cache",
"_client_config",
"_endpoint",
"_exceptions_factory",
"_exceptions",
"exceptions",
"_loader",
"_request_signer",
"_response_parser",
"_serializer",
"meta",
]
__dict__ = object.__getattribute__(self, "__dict__")
if (__dict__.get("_is_pytest_localstack", False)
or key not in proxied_keys):
# Don't proxy clients that are already Localstack clients
return object.__getattribute__(self, key)
if self not in botocore.client.BaseClient._proxy_clients:
try:
meta = __dict__["meta"]
except KeyError:
raise AttributeError("meta")
proxy = factory.default_session.create_client(
meta.service_model.service_name,
# config=config,
config=__dict__["_client_config"],
)
botocore.client.BaseClient._proxy_clients[self] = proxy
return object.__getattribute__(
botocore.client.BaseClient._proxy_clients[self], key)
patches.append(
mock.patch(
"botocore.client.BaseClient.__getattribute__",
new_getattribute,
create=True,
))
with utils.nested(*patches):
yield
finally:
logger.debug("exit patch")
def patch_botocore(self):
"""Context manager that will patch botocore to use Localstack.
Since boto3 relies on botocore to perform API calls, this method
also effectively patches boto3.
"""
# Q: Why is this method so complicated?
# A: Because the most common usecase is something like this::
#
# >>> import boto3
# >>>
# >>> S3 = boto3.resource('s3')
# >>>
# >>> def do_stuff():
# >>> bucket = S3.Bucket('foobar')
# >>> bucket.create()
# ...
#
# The `S3` resource creates a botocore Client when the module
# is loaded. It's hard to patch existing Client instances since
# there isn't a good way to find them.
# You must add a descriptor to the Client class
# that overrides specific properties of the Client instances.
# TODO: Could we use use `gc.get_referrers()` to find instances?
logger.debug("enter patch")
if boto3 is not None:
preexisting_boto3_session = boto3.DEFAULT_SESSION
try:
factory = self
patches = []
# Step 1: patch botocore Session to use Localstack.
attr = {}
@property
def localstack_session(self):
# Simlate the 'localstack_session' attr from Session class below.
# Patch this into the botocore Session class.
if "localstack_session" in self.__dict__:
# We're patching this into the base botocore Session,
# but we don't want to override things for the Session
# subclass below.
return self.__dict__["localstack_session"]
return factory.localstack_session
@localstack_session.setter
def localstack_session(self, value):
assert isinstance(self, Session)
self.__dict__["localstack_session"] = value
attr["localstack_session"] = localstack_session
@property
def _components(self):
if isinstance(self, Session):
try:
return self.__dict__["_components"]
except KeyError:
raise AttributeError("_components")
proxy_components = botocore.session.Session._proxy_components
if self not in proxy_components:
proxy_components[self] = botocore.session.ComponentLocator(
)
self._register_components()
return proxy_components[self]
@_components.setter
def _components(self, value):
self.__dict__["_components"] = value
@property
def _internal_components(self):
if isinstance(self, Session):
try:
return self.__dict__["_internal_components"]
except KeyError:
raise AttributeError("_internal_components")
proxy_components = botocore.session.Session._proxy_components
if self not in proxy_components:
proxy_components[self] = DebugComponentLocator()
self._register_components()
return proxy_components[self]
@_internal_components.setter
def _internal_components(self, value):
self.__dict__["_internal_components"] = value
attr.update({
"_components": _components,
"_internal_components": _internal_components,
"_proxy_components": weakref.WeakKeyDictionary(),
})
@property
def _credentials(self):
return self._proxy_credentials.get(self)
@_credentials.setter
def _credentials(self, value):
self._proxy_credentials[self] = value
attr.update({
"_credentials": _credentials,
"_proxy_credentials": weakref.WeakKeyDictionary(),
})
patches.append(
mock.patch.multiple("botocore.session.Session",
create=True,
**attr))
patches.append(
mock.patch.multiple(
botocore.session.Session,
_register_endpoint_resolver=utils.unbind(
Session._register_endpoint_resolver),
_register_credential_provider=utils.unbind(
Session._register_credential_provider),
create_client=utils.unbind(Session.create_client),
))
# Step 2: Safety checks
# Make absolutly sure we use Localstack and not AWS.
_original_convert_to_request_dict = (
botocore.client.BaseClient._convert_to_request_dict)
@functools.wraps(_original_convert_to_request_dict)
def _convert_to_request_dict(self, *args, **kwargs):
request_dict = _original_convert_to_request_dict(
self, *args, **kwargs)
assert any((
factory.localstack_session.hostname in request_dict["url"],
socket.gethostname() in request_dict["url"],
))
return request_dict
patches.append(
mock.patch(
"botocore.client.BaseClient._convert_to_request_dict",
_convert_to_request_dict,
))
# Step 3: Patch existing clients
# Patching botocore Session doesn't help with an existing
# botocore Clients objects. They will have already been created with
# endpoints aimed at AWS. We need to patch botocore.client.BaseClient
# to temporarially act like a Localstack.
original_init = botocore.client.BaseClient.__init__
@functools.wraps(original_init)
def new_init(self, *args, **kwargs):
# Every client created during the patch is a Localstack client.
# Set this flag so that the proxy_client_attr() stuff below
# won't break during original_init().
self._is_pytest_localstack = True
original_init(self, *args, **kwargs)
patches.append(
mock.patch.multiple(botocore.client.BaseClient,
__init__=new_init))
# Create a place to store proxy clients.
patches.append(
mock.patch(
"botocore.client.BaseClient._proxy_clients",
weakref.WeakKeyDictionary(),
create=True,
))
def new_getattribute(self, key):
if key.startswith("__"):
return object.__getattribute__(self, key)
proxied_keys = [
"_cache",
"_client_config",
"_endpoint",
"_exceptions_factory",
"_exceptions",
"exceptions",
"_loader",
"_request_signer",
"_response_parser",
"_serializer",
"meta",
]
__dict__ = object.__getattribute__(self, "__dict__")
if (__dict__.get("_is_pytest_localstack", False)
or key not in proxied_keys):
# Don't proxy clients that are already Localstack clients
return object.__getattribute__(self, key)
if self not in botocore.client.BaseClient._proxy_clients:
try:
meta = __dict__["meta"]
except KeyError:
raise AttributeError("meta")
proxy = factory.default_session.create_client(
meta.service_model.service_name,
# config=config,
config=__dict__["_client_config"],
)
botocore.client.BaseClient._proxy_clients[self] = proxy
return object.__getattribute__(
botocore.client.BaseClient._proxy_clients[self], key)
patches.append(
mock.patch(
"botocore.client.BaseClient.__getattribute__",
new_getattribute,
create=True,
))
# STS is sneaky and even after patching the endpoint it has a final custom check
# to see whether it should override with the global endpoint url... patch that too
patches.append(
mock.patch(
"botocore.args.ClientArgsCreator._should_set_global_sts_endpoint",
lambda *args, **kwargs: False,
))
with utils.nested(*patches):
yield
finally:
logger.debug("exit patch")
if boto3 is not None:
boto3.DEFAULT_SESSION = preexisting_boto3_session