Writing Simple HTTP Server in Python (With REST and JSON)

simpleRestfulHttpServerInPython

There are many already existing powerful http servers that can be used in python e.g. gevent, twisted web server. However, they are a bit complex to use and you cannot start them in a thread other than the main thread.

Here is a sample of basic http server using "BaseHTTPRequestHandler". The example exposed two rest interfaces:

To ingest records into the web server
To retrieve already ingested records from the web server
The records are assumed to be JSON based, however, any type of records can be ingested.

[sourcecode language="python" wraplines="false" collapse="false"]
from BaseHTTPServer import BaseHTTPRequestHandler,HTTPServer
from SocketServer import ThreadingMixIn
import threading
import argparse
import re
import cgi

class LocalData(object):
  records = {}

class HTTPRequestHandler(BaseHTTPRequestHandler):
  def do_POST(self):
    if None != re.search('/api/v1/addrecord/*', self.path):
      ctype, pdict = cgi.parse_header(self.headers.getheader('content-type'))
      if ctype == 'application/json':
        length = int(self.headers.getheader('content-length'))
        data = cgi.parse_qs(self.rfile.read(length), keep_blank_values=1)
        recordID = self.path.split('/')[-1]
        LocalData.records[recordID] = data
        print "record %s is added successfully" % recordID
      else:
        data = {}
      self.send_response(200)
      self.end_headers()
    else:
      self.send_response(403)
      self.send_header('Content-Type', 'application/json')
      self.end_headers()
    return

  def do_GET(self):
    if None != re.search('/api/v1/getrecord/*', self.path):
      recordID = self.path.split('/')[-1]
      if LocalData.records.has_key(recordID):
        self.send_response(200)
        self.send_header('Content-Type', 'application/json')
        self.end_headers()
        self.wfile.write(LocalData.records[recordID])
      else:
        self.send_response(400, 'Bad Request: record does not exist')
        self.send_header('Content-Type', 'application/json')
        self.end_headers()
    else:
      self.send_response(403)
      self.send_header('Content-Type', 'application/json')
      self.end_headers()
    return

class ThreadedHTTPServer(ThreadingMixIn, HTTPServer):
  allow_reuse_address = True

  def shutdown(self):
    self.socket.close()
    HTTPServer.shutdown(self)

class SimpleHttpServer():
  def __init__(self, ip, port):
    self.server = ThreadedHTTPServer((ip,port), HTTPRequestHandler)

  def start(self):
    self.server_thread = threading.Thread(target=self.server.serve_forever)
    self.server_thread.daemon = True
    self.server_thread.start()

  def waitForThread(self):
    self.server_thread.join()

  def addRecord(self, recordID, jsonEncodedRecord):
    LocalData.records[recordID] = jsonEncodedRecord

  def stop(self):
    self.server.shutdown()
    self.waitForThread()

if __name__=='__main__':
  parser = argparse.ArgumentParser(description='HTTP Server')
  parser.add_argument('port', type=int, help='Listening port for HTTP Server')
  parser.add_argument('ip', help='HTTP Server IP')
  args = parser.parse_args()

  server = SimpleHttpServer(args.ip, args.port)
  print 'HTTP Server Running...........'
  server.start()
  server.waitForThread()

[/sourcecode]
Usage:

Copy paste the code above and name it simplewebserver.py
Starting WebServer:
python simplewebserver.py
POST addrecord example using curl:
curl -X POST http://localhost:8080/api/v1/addrecord/1 -d '{\"asif1\":\"test1\"}' -H "Content-Type: application/json"
GET record example using curl:
curl -X GET http://localhost:8080/api/v1/getrecord/test -H "Content-Type: application/json"