#!/usr/bin/python

import traceback, json, socket, struct, os, sys

import rethinkdb

import flask

sys.path.append('/handler')

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

app = flask.Flask(__name__)

PROCESSES_DEFAULT = 10

PORT = 8080

initialized = False

config = None

db_conn = None

# run once per process

def init():

global initialized, config, db_conn

if initialized:

return

sys.stdout = sys.stderr # flask supresses stdout :(

with open('config.json') as f:

config = json.loads(f.read())

if config.get('db', None) == 'rethinkdb':

addr = os.environ.get('RETHINKDB_PORT_28015_TCP', None)

if addr != None:

host, port = addr.split('//')[-1].split(':')

else:

host, port = get_default_gateway_linux(), '28015'

try:

db_conn = rethinkdb.connect(host, int(port))

except:

print "connection to rethinkdb failed"

initialized = True

# source: http://stackoverflow.com/a/6556951

def get_default_gateway_linux():

"""Read the default gateway directly from /proc."""

with open("/proc/net/route") as fh:

for line in fh:

fields = line.strip().split()

if fields[1] != '00000000' or not int(fields[3], 16) & 2:

continue

return socket.inet_ntoa(struct.pack("<L", int(fields[2], 16)))

# catch everything

@app.route('/', defaults={'path': ''}, methods=['POST'])

@app.route('/<path:path>', methods=['POST'])

def flask_post(path):

try:

init()

flask.request.get_data()

data = flask.request.data

try :

event = json.loads(data)

except:

return ('bad POST data: "%s"'%str(data), 400)

return json.dumps(lambda_func.handler(db_conn, event))

except Exception:

return (traceback.format_exc(), 500) # internal error

def main():

with open('config.json') as f:

config = json.loads(f.read())

procs = config.get('processes', PROCESSES_DEFAULT)

print 'Starting %d flask processes' % procs

app.run(processes=procs, host='0.0.0.0', port=PORT)

if __name__ == '__main__':

main()