class FileObserver_start(TestCase):
@patch("samcli.lib.utils.file_observer.Observer")
@patch("samcli.lib.utils.file_observer.PatternMatchingEventHandler")
def setUp(self, PatternMatchingEventHandlerMock, ObserverMock):
self.on_change = Mock()
self.watchdog_observer_mock = Mock()
ObserverMock.return_value = self.watchdog_observer_mock
self.handler_mock = Mock()
PatternMatchingEventHandlerMock.return_value = self.handler_mock
self.observer = FileObserver(self.on_change)
self.observer._watch_dog_observed_paths = {
"parent_path1": ["parent_path1/path1", "parent_path1/path2"],
"parent_path2": ["parent_path2/path3"],
}
self.observer._observed_paths = {
"parent_path1/path1": "1234",
"parent_path1/path2": "4567",
"parent_path2/path3": "7890",
}
self._parent1_watcher_mock = Mock()
self._parent2_watcher_mock = Mock()
self.observer._observed_watches = {
"parent_path1": self._parent1_watcher_mock,
"parent_path2": self._parent2_watcher_mock,
}
def test_start_non_started_observer_successfully(self):
self.watchdog_observer_mock.is_alive.return_value = False
self.observer.start()
self.watchdog_observer_mock.start.assert_called_with()
def test_start_started_observer_does_not_call_watchdog_observer(self):
self.watchdog_observer_mock.is_alive.return_value = True
self.observer.start()
self.watchdog_observer_mock.start.assert_not_called()
class WarmLambdaRuntime(LambdaRuntime):
"""
This class extends the LambdaRuntime class to add the Warm containers feature. This class handles the
warm containers life cycle.
"""
def __init__(self, container_manager, image_builder):
"""
Initialize the Local Lambda runtime
Parameters
----------
container_manager samcli.local.docker.manager.ContainerManager
Instance of the ContainerManager class that can run a local Docker container
image_builder samcli.local.docker.lambda_image.LambdaImage
Instance of the LambdaImage class that can create am image
warm_containers bool
Determines if the warm containers is enabled or not.
"""
self._containers = {}
# used to observe any code change in case if warm containers is enabled to support the reloading
self._observed_paths = {}
self._observer = FileObserver(self._on_code_change)
super().__init__(container_manager, image_builder)
def create(self, function_config, debug_context=None, event=None):
"""
Create a new Container for the passed function, then store it in a dictionary using the function name,
so it can be retrieved later and used in the other functions. Make sure to use the debug_context only
if the function_config.name equals debug_context.debug-function or the warm_containers option is disabled
Parameters
----------
function_config FunctionConfig
Configuration of the function to create a new Container for it.
debug_context DebugContext
Debugging context for the function (includes port, args, and path)
event str
input event passed to Lambda function
Returns
-------
Container
the created container
"""
# reuse the cached container if it is created
container = self._containers.get(function_config.name, None)
if container and container.is_created():
LOG.info(
"Reuse the created warm container for Lambda function '%s'",
function_config.name)
return container
# debug_context should be used only if the function name is the one defined
# in debug-function option
if debug_context and debug_context.debug_function != function_config.name:
LOG.debug(
"Disable the debugging for Lambda Function %s, as the passed debug function is %s",
function_config.name,
debug_context.debug_function,
)
debug_context = None
container = super().create(function_config, debug_context, None)
self._containers[function_config.name] = container
self._add_function_to_observer(function_config)
return container
def _on_invoke_done(self, container):
"""
Cleanup the created resources, just before the invoke function ends.
In warm containers, the running containers will be closed just before the end of te command execution,
so no action is done here
Parameters
----------
container: Container
The current running container
"""
def _add_function_to_observer(self, function_config):
"""
observe the function code path, so the function container be reload if its code got changed.
Parameters
----------
function_config: FunctionConfig
Configuration of the function to create a new Container for it.
"""
code_paths = [function_config.code_abs_path]
if function_config.layers:
code_paths += [layer.codeuri for layer in function_config.layers]
for code_path in code_paths:
functions = self._observed_paths.get(code_path, [])
functions += [function_config]
self._observed_paths[code_path] = functions
self._observer.watch(code_path)
self._observer.start()
def _configure_interrupt(self, function_name, timeout, container,
is_debugging):
"""
When a Lambda function is executing, we setup certain interrupt handlers to stop the execution.
Usually, we setup a function timeout interrupt to kill the container after timeout expires. If debugging though,
we don't enforce a timeout. But we setup a SIGINT interrupt to catch Ctrl+C and terminate the container.
Parameters
----------
function_name: str
Name of the function we are running
timeout: int
Timeout in seconds
container: samcli.local.docker.container.Container
Instance of a container to terminate
is_debugging: bool
Are we debugging?
Returns
-------
threading.Timer
Timer object, if we setup a timer. None otherwise
"""
def timer_handler():
# NOTE: This handler runs in a separate thread. So don't try to mutate any non-thread-safe data structures
LOG.info("Function '%s' timed out after %d seconds", function_name,
timeout)
def signal_handler(sig, frame):
# NOTE: This handler runs in a separate thread. So don't try to mutate any non-thread-safe data structures
LOG.info("Execution of function %s was interrupted", function_name)
if is_debugging:
LOG.debug("Setting up SIGTERM interrupt handler")
signal.signal(signal.SIGTERM, signal_handler)
return None
# Start a timer, we'll use this to abort the function if it runs beyond the specified timeout
LOG.debug("Starting a timer for %s seconds for function '%s'", timeout,
function_name)
timer = threading.Timer(timeout, timer_handler, ())
timer.start()
return timer
def clean_running_containers_and_related_resources(self):
"""
Clean the running containers, the decompressed code dirs, and stop the created observer
"""
LOG.debug("Terminating all running warm containers")
for function_name, container in self._containers.items():
LOG.debug(
"Terminate running warm container for Lambda Function '%s'",
function_name)
self._container_manager.stop(container)
self._clean_decompressed_paths()
self._observer.stop()
def _on_code_change(self, paths):
"""
Handles the lambda function code change event. it determines if there is a real change in the code
by comparing the checksum of the code path before and after the event.
Parameters
----------
paths: list of str
the paths of the code that got changed
"""
for path in paths:
functions = self._observed_paths.get(path, []).copy()
for function_config in functions:
function_name = function_config.name
LOG.info(
"Lambda Function '%s' code has been changed, terminate its warm container. "
"The new container will be created in lazy mode",
function_name,
)
container = self._containers.get(function_name, None)
if container:
self._container_manager.stop(container)
self._containers.pop(function_name, None)
self._remove_observed_lambda_function(function_config)
def _remove_observed_lambda_function(self, function_config):
"""
remove the lambda function's code paths from the observed paths
Parameters
----------
function_config: FunctionConfig
Configuration of the function to invoke
"""
code_paths = [function_config.code_abs_path]
if function_config.layers:
code_paths += [layer.codeuri for layer in function_config.layers]
for path in code_paths:
functions = self._observed_paths.get(path, [])
if function_config in functions:
functions.remove(function_config)
if not functions:
self._observed_paths.pop(path, None)
self._observer.unwatch(path)