def test_function_result_is_available_in_stdout_and_logs_in_stderr(self):
# This is the JSON result from Lambda function
# Convert to proper binary type to be compatible with Python 2 & 3
expected_output = b'{"a":"b"}'
expected_stderr = b"**This string is printed from Lambda function**"
layer_downloader = LayerDownloader("./", "./")
image_builder = LambdaImage(layer_downloader, False, False)
container = LambdaContainer(self.runtime, self.handler, self.code_dir,
self.layers, image_builder)
stdout_stream = io.BytesIO()
stderr_stream = io.BytesIO()
stdout_stream_writer = StreamWriter(stdout_stream)
stderr_stream_writer = StreamWriter(stderr_stream)
with self._create(container):
container.start()
container.wait_for_logs(stdout=stdout_stream_writer,
stderr=stderr_stream_writer)
function_output = stdout_stream.getvalue()
function_stderr = stderr_stream.getvalue()
self.assertEqual(function_output.strip(), expected_output)
self.assertIn(expected_stderr, function_stderr)
def test_function_result_is_available_in_stdout_and_logs_in_stderr(self):
# This is the JSON result from Lambda function
# Convert to proper binary type to be compatible with Python 2 & 3
expected_output = b'{"a":"b"}'
expected_stderr = b"**This string is printed from Lambda function**"
layer_downloader = LayerDownloader("./", "./")
image_builder = LambdaImage(layer_downloader, False, False)
container = LambdaContainer(self.runtime, self.handler, self.code_dir, self.layers, image_builder)
stdout_stream = io.BytesIO()
stderr_stream = io.BytesIO()
stdout_stream_writer = StreamWriter(stdout_stream)
stderr_stream_writer = StreamWriter(stderr_stream)
with self._create(container):
container.start()
container.wait_for_logs(stdout=stdout_stream_writer, stderr=stderr_stream_writer)
function_output = stdout_stream.getvalue()
function_stderr = stderr_stream.getvalue()
self.assertEquals(function_output.strip(), expected_output)
self.assertIn(expected_stderr, function_stderr)
def test_function_result_is_available_in_stdout_and_logs_in_stderr(self):
# This is the JSON result from Lambda function
# Convert to proper binary type to be compatible with Python 2 & 3
expected_output = six.binary_type('{"a":"b"}'.encode('utf-8'))
expected_stderr = six.binary_type(
"**This string is printed from Lambda function**".encode("utf-8"))
container = LambdaContainer(self.runtime, self.handler, self.code_dir)
stdout_stream = io.BytesIO()
stderr_stream = io.BytesIO()
with self._create(container):
container.start()
container.wait_for_logs(stdout=stdout_stream, stderr=stderr_stream)
function_output = stdout_stream.getvalue()
function_stderr = stderr_stream.getvalue()
self.assertEquals(function_output.strip(), expected_output)
self.assertIn(expected_stderr, function_stderr)
def invoke(self,
function_config,
event,
debug_context=None,
stdout=None,
stderr=None):
"""
Invoke the given Lambda function locally.
##### NOTE: THIS IS A LONG BLOCKING CALL #####
This method will block until either the Lambda function completes or timed out, which could be seconds.
A blocking call will block the thread preventing any other operations from happening. If you are using this
method in a web-server or in contexts where your application needs to be responsive when function is running,
take care to invoke the function in a separate thread. Co-Routines or micro-threads might not perform well
because the underlying implementation essentially blocks on a socket, which is synchronous.
:param FunctionConfig function_config: Configuration of the function to invoke
:param event: String input event passed to Lambda function
:param DebugContext debug_context: Debugging context for the function (includes port, args, and path)
:param io.IOBase stdout: Optional. IO Stream to that receives stdout text from container.
:param io.IOBase stderr: Optional. IO Stream that receives stderr text from container
:raises Keyboard
"""
timer = None
# Update with event input
environ = function_config.env_vars
environ.add_lambda_event_body(event)
# Generate a dictionary of environment variable key:values
env_vars = environ.resolve()
with self._get_code_dir(function_config.code_abs_path) as code_dir:
container = LambdaContainer(function_config.runtime,
function_config.handler,
code_dir,
function_config.layers,
self._image_builder,
memory_mb=function_config.memory,
env_vars=env_vars,
debug_options=debug_context)
try:
# Start the container. This call returns immediately after the container starts
self._container_manager.run(container)
# Setup appropriate interrupt - timeout or Ctrl+C - before function starts executing.
#
# Start the timer **after** container starts. Container startup takes several seconds, only after which,
# our Lambda function code will run. Starting the timer is a reasonable approximation that function has
# started running.
timer = self._configure_interrupt(function_config.name,
function_config.timeout,
container,
bool(debug_context))
# NOTE: BLOCKING METHOD
# Block the thread waiting to fetch logs from the container. This method will return after container
# terminates, either successfully or killed by one of the interrupt handlers above.
container.wait_for_logs(stdout=stdout, stderr=stderr)
except KeyboardInterrupt:
# When user presses Ctrl+C, we receive a Keyboard Interrupt. This is especially very common when
# container is in debugging mode. We have special handling of Ctrl+C. So handle KeyboardInterrupt
# and swallow the exception. The ``finally`` block will also take care of cleaning it up.
LOG.debug("Ctrl+C was pressed. Aborting Lambda execution")
finally:
# We will be done with execution, if either the execution completed or an interrupt was fired
# Any case, cleanup the timer and container.
#
# If we are in debugging mode, timer would not be created. So skip cleanup of the timer
if timer:
timer.cancel()
self._container_manager.stop(container)
def invoke(self,
function_config,
event,
debug_context=None,
stdout=None,
stderr=None):
"""
Invoke the given Lambda function locally.
##### NOTE: THIS IS A LONG BLOCKING CALL #####
This method will block until either the Lambda function completes or timed out, which could be seconds.
A blocking call will block the thread preventing any other operations from happening. If you are using this
method in a web-server or in contexts where your application needs to be responsive when function is running,
take care to invoke the function in a separate thread. Co-Routines or micro-threads might not perform well
because the underlying implementation essentially blocks on a socket, which is synchronous.
:param FunctionConfig function_config: Configuration of the function to invoke
:param event: String input event passed to Lambda function
:param DebugContext debug_context: Debugging context for the function (includes port, args, and path)
:param io.IOBase stdout: Optional. IO Stream to that receives stdout text from container.
:param io.IOBase stderr: Optional. IO Stream that receives stderr text from container
:raises Keyboard
"""
timer = None
# Update with event input
environ = function_config.env_vars
environ.add_lambda_event_body(event)
# Generate a dictionary of environment variable key:values
env_vars = environ.resolve()
with self._get_code_dir(function_config.code_abs_path) as code_dir:
container = LambdaContainer(function_config.runtime,
function_config.handler,
code_dir,
function_config.layers,
self._image_builder,
memory_mb=function_config.memory,
env_vars=env_vars,
debug_options=debug_context)
try:
# Start the container. This call returns immediately after the container starts
self._container_manager.run(container)
# Setup appropriate interrupt - timeout or Ctrl+C - before function starts executing.
#
# Start the timer **after** container starts. Container startup takes several seconds, only after which,
# our Lambda function code will run. Starting the timer is a reasonable approximation that function has
# started running.
timer = self._configure_interrupt(function_config.name,
function_config.timeout,
container,
bool(debug_context))
# NOTE: BLOCKING METHOD
# Block the thread waiting to fetch logs from the container. This method will return after container
# terminates, either successfully or killed by one of the interrupt handlers above.
container.wait_for_logs(stdout=stdout, stderr=stderr)
except KeyboardInterrupt:
# When user presses Ctrl+C, we receive a Keyboard Interrupt. This is especially very common when
# container is in debugging mode. We have special handling of Ctrl+C. So handle KeyboardInterrupt
# and swallow the exception. The ``finally`` block will also take care of cleaning it up.
LOG.debug("Ctrl+C was pressed. Aborting Lambda execution")
finally:
# We will be done with execution, if either the execution completed or an interrupt was fired
# Any case, cleanup the timer and container.
#
# If we are in debugging mode, timer would not be created. So skip cleanup of the timer
if timer:
timer.cancel()
self._container_manager.stop(container)
