import os, sys, json, argparse, importlib, traceback

import tornado.ioloop

import tornado.web

import tornado.httpserver

import tornado.netutil

HOST_DIR = '/host'

PKGS_DIR = '/packages'

HANDLER_DIR = '/handler'

sys.path.append(PKGS_DIR)

sys.path.append(HANDLER_DIR)

FS_PATH = os.path.join(HOST_DIR, 'fs.sock')

SOCK_PATH = os.path.join(HOST_DIR, 'ol.sock')

STDOUT_PATH = os.path.join(HOST_DIR, 'stdout')

STDERR_PATH = os.path.join(HOST_DIR, 'stderr')

PROCESSES_DEFAULT = 10

initialized = False

parser = argparse.ArgumentParser(description='Listen and serve cache requests or lambda invocations.')

parser.add_argument('--cache', action='store_true', default=False, help='Begin as a cache entry.')

# run after forking into sandbox

def init():

global initialized, lambda_func

if initialized:

return

# assume submitted .py file is /handler/lambda_func.py

import lambda_func

initialized = True

class SockFileHandler(tornado.web.RequestHandler):

def post(self):

try:

data = self.request.body

try :

event = json.loads(data)

except:

self.set_status(400)

self.write('bad POST data: "%s"'%str(data))

return

self.write(json.dumps(lambda_func.handler(event)))

except Exception:

self.set_status(500) # internal error

self.write(traceback.format_exc())

tornado_app = tornado.web.Application([

(r".*", SockFileHandler),

])

# listen on sock file with Tornado

def lambda_server():

global HOST_PIPE

init()

server = tornado.httpserver.HTTPServer(tornado_app)

socket = tornado.netutil.bind_unix_socket(SOCK_PATH)

server.add_socket(socket)

# notify worker server that we are ready through stdout

# flush is necessary, and don't put it after tornado start; won't work

with open('/host/server_pipe', 'w') as pipe:

pipe.write('ready')

tornado.ioloop.IOLoop.instance().start()

server.start(PROCESSES_DEFAULT)

# listen for fds to forkenter

def cache_loop():

import ns

signal = "cache"

r = -1

count = 0

# only child meant to serve ever escapes the loop

while r != 0 or signal == "cache":

if r == 0:

print('RESET')

flush()

ns.reset()

print('LISTENING')

flush()

data = ns.fdlisten(FS_PATH).split()

flush()

mods = data[:-1]

signal = data[-1]

r = ns.forkenter()

sys.stdout.flush()

if r == 0:

redirect()

# import modules

for mod in mods:

print('importing: %s' % mod)

try:

globals()[mod] = importlib.import_module(mod)

except Exception as e:

print('failed to import %s with: %s' % (mod, e))

print('signal: %s' % signal)

flush()

print('')

flush()

count += 1

print('SERVING HANDLERS')

flush()

lambda_server()

def flush():

sys.stdout.flush()

sys.stderr.flush()

def redirect():

sys.stdout.close()

sys.stderr.close()

sys.stdout = open(STDOUT_PATH, 'w')

sys.stderr = open(STDERR_PATH, 'w')

if __name__ == '__main__':

args = parser.parse_args()

redirect()

if args.cache:

cache_loop()

else:

lambda_server()