postserve/server.py

86 lines
3.0 KiB
Python

#!/usr/bin/env python
"""
This is a simple vector tile server that returns a PBF tile for /tiles/{z}/{x}/{y}.pbf requests
Use these environment variables to configure PostgreSQL access:
POSTGRES_HOST, POSTGRES_PORT, POSTGRES_DB, POSTGRES_PASSWORD
Usage:
server <prepared-sql-file> [--fname <name>] [--port <port>]
server --help
server --version
<prepared-sql-file> SQL file generated by generate-sqltomvt script with the --prepared flag
Options:
--fname=<name> Name of the generated function [default: gettile]
-p --port=<port> Serve on this port [default: 8080]
--help Show this screen.
--version Show version.
"""
import tornado.ioloop
import tornado.web
import io
import os
from docopt import docopt
from sqlalchemy import create_engine, inspect
from sqlalchemy.orm import sessionmaker
class GetTile(tornado.web.RequestHandler):
def initialize(self, session, query):
self.db_session = session
self.db_query = query
def get(self, z, x, y):
z, x, y = int(z), int(x), int(y)
try:
result = self.db_session.execute(self.db_query, params=dict(z=z, x=x, y=y)).fetchall()
if result:
self.set_header("Content-Type", "application/x-protobuf")
self.set_header("Content-Disposition", "attachment")
self.set_header("Access-Control-Allow-Origin", "*")
value = io.BytesIO(result[0][0]).getvalue()
self.write(value)
print('{0},{1},{2} returned {3} bytes'.format(z, x, y, len(value)))
else:
self.clear()
self.set_status(404)
print('Got NULL result for {0},{1},{2}'.format(z, x, y))
except Exception as err:
print('{0},{1},{2} threw an exception {3}'.format(z, x, y, err))
raise
def main(args):
sqlfile = args['<prepared-sql-file>']
with open(sqlfile, 'r') as stream:
prepared = stream.read()
pghost = os.getenv('POSTGRES_HOST', 'localhost') + ':' + os.getenv('POSTGRES_PORT', '5432')
pgdb = os.getenv('POSTGRES_DB', 'openmaptiles')
pgcreds = os.getenv('POSTGRES_USER', 'openmaptiles') + ':' + os.getenv('POSTGRES_PASSWORD', 'openmaptiles')
engine = create_engine('postgresql://' + pgcreds + '@' + pghost + '/' + pgdb)
print('Connecting to PostgreSQL at {0}, db={1}'.format(pghost, pgdb))
inspector = inspect(engine)
session = sessionmaker(bind=engine)()
session.execute(prepared)
query = "EXECUTE {0}(:z, :x, :y)".format(args['--fname'])
print('Loaded {0}, will use "{1}" to get vector tiles.'.format(sqlfile, query))
port = int(args['--port'])
application = tornado.web.Application([(
r"/tiles/([0-9]+)/([0-9]+)/([0-9]+).pbf",
GetTile,
dict(session=session, query=query)
)])
application.listen(port)
print("Postserve started, listening on 0.0.0.0:{0}".format(port))
tornado.ioloop.IOLoop.instance().start()
if __name__ == "__main__":
main(docopt(__doc__, version="1.0"))