def _launch_nested_container_session(self):
"""Sends a request to the Mesos Agent to launch a new
nested container and attach to its output stream.
The output stream is then sent back in the response.
"""
message = {
'type': "LAUNCH_NESTED_CONTAINER_SESSION",
'launch_nested_container_session': {
'container_id': {
'parent': { 'value': self.parent_id },
'value': self.container_id
},
'command': {
'value': self.cmd,
'arguments': [self.cmd] + self.args,
'shell': False}}}
# If we have to launch in a task group, we need double nesting
if self.parent_container_id is not None:
message['launch_nested_container_session']['container_id']['parent']['parent'] = { 'value': self.parent_container_id }
if self.env is not None:
env_vars = []
env_var_regex = re.compile('^([A-Z_][A-Z0-9_]*)=(.*)$')
for env_var in self.env.split(':'):
matches = env_var_regex.match(env_var)
if matches and len(matches.groups()) == 2:
env_vars.append({
'name': matches.group(1),
'type': 'VALUE',
'value': matches.group(2)
})
message['launch_nested_container_session']['command']['environment'] = {
'variables': env_vars
}
if not self.user is None:
message['launch_nested_container_session']['command']['user'] =\
self.user
if self.tty:
message[
'launch_nested_container_session'][
'container'] = {
'type': 'MESOS',
'tty_info': {}}
req_extra_args = {
'stream': True,
'headers': {
'Content-Type': 'application/json',
'Accept': 'application/recordio',
'Message-Accept': 'application/json'}}
response = http.post(
self.agent_url,
data=json.dumps(message),
timeout=None,
**req_extra_args)
self._process_output_stream(response)
def _launch_nested_container_session(self):
"""Sends a request to the Mesos Agent to launch a new
nested container and attach to its output stream.
The output stream is then sent back in the response.
"""
message = {
'type': "LAUNCH_NESTED_CONTAINER_SESSION",
'launch_nested_container_session': {
'container_id': {
'parent': {
'value': self.parent_id
},
'value': self.container_id
},
'command': {
'value': self.cmd,
'arguments': [self.cmd] + self.args,
'shell': False
}
}
}
if not self.user is None:
message['launch_nested_container_session']['command']['user'] =\
self.user
if self.tty:
message['launch_nested_container_session']['container'] = {
'type': 'MESOS',
'tty_info': {}
}
req_extra_args = {
'stream': True,
'headers': {
'Content-Type': 'application/json',
'Accept': 'application/recordio',
'Message-Accept': 'application/json'
}
}
response = http.post(self.agent_url,
data=json.dumps(message),
timeout=None,
**req_extra_args)
self._process_output_stream(response)
def _attach_container_input(self):
"""Streams all input data (e.g. STDIN) from the client to the agent
"""
def _initial_input_streamer():
"""Generator function yielding the initial ATTACH_CONTAINER_INPUT
message for streaming. We have a separate generator for this so
that we can attempt the connection once before committing to a
persistent connection where we stream the rest of the input.
:returns: A RecordIO encoded message
"""
message = {
'type': 'ATTACH_CONTAINER_INPUT',
'attach_container_input': {
'type': 'CONTAINER_ID',
'container_id': {
'parent': {
'value': self.parent_id
},
'value': self.container_id
}
}
}
yield self.encoder.encode(message)
def _input_streamer():
"""Generator function yielding ATTACH_CONTAINER_INPUT
messages for streaming. It yields the _intitial_input_streamer()
message, followed by messages from the input_queue on each
subsequent call.
:returns: A RecordIO encoded message
"""
yield next(_initial_input_streamer())
while True:
record = self.input_queue.get()
if not record:
break
yield record
req_extra_args = {
'headers': {
'Content-Type': 'application/recordio',
'Message-Content-Type': 'application/json',
'Accept': 'application/json',
'Connection': 'close',
'Transfer-Encoding': 'chunked'
}
}
# Ensure we don't try to attach our input to a container that isn't
# fully up and running by waiting until the
# `_process_output_stream` function signals us that it's ready.
self.attach_input_event.wait()
# Send an intial "Test" message to ensure that we are able to
# establish a connection with the agent. If we aren't we will throw
# an exception and break out of this thread. However, in cases where
# we receive a 500 response from the agent, we actually want to
# continue without throwing an exception. A 500 error indicates that
# we can't connect to the container because it has already finished
# running. In that case we continue running to allow the output queue
# to be flushed.
try:
http.post(self.agent_url,
data=_initial_input_streamer(),
**req_extra_args)
except MesosHTTPException as e:
if not e.response.status_code == 500:
raise e
# If we succeeded with that connection, unblock process_output_stream()
# from sending output data to the output thread.
self.print_output_event.set()
# Begin streaming the input.
http.post(self.agent_url,
data=_input_streamer(),
timeout=None,
**req_extra_args)