Minimal JSON HTTP server in python

README.md

A minimal HTTP server in python. It sends a JSON Hello World for GET requests, and echoes back JSON for POST requests.

python server.py 8009
Starting httpd on port 8009...

curl http://localhost:8009
{"received": "ok", "hello": "world"}

curl --data "{\"this\":\"is a test\"}" --header "Content-Type: application/json" http://localhost:8009
{"this": "is a test", "received": "ok"}

Adapted from this Gist, with the addition of code for reading the request body taken from this article.

Please be careful when using a server like this on production environments, because it lacks many important features (threading to name one). You can consult the python documentation about BaseHTTPServer to learn something useful to improve it.

If you are on Ubuntu, you can install this code as a service with an init script (hopefully, with some modifications that make it actually do something useful). Just modify the include server.conf to suit your needs (possibly renaming it and redirecting output to some log files instead of /dev/null), and copy it into /etc/init/. You can then start/stop/restart the server with the usual service command:

sudo service server start

server.conf

description "Example JSON HTTP server"
author      "nitaku - [email protected]"

start on started mountall
stop on shutdown

respawn
respawn limit 99 5

script
  exec sudo -u www-data /usr/bin/python /data/examples/python_minimal_http/server.py 8009 >> /dev/null 2>> /dev/null

end script

post-start script
end script

server.py

from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
import SocketServer
import json
import cgi

class Server(BaseHTTPRequestHandler):
    def _set_headers(self):
        self.send_response(200)
        self.send_header('Content-type', 'application/json')
        self.end_headers()
        
    def do_HEAD(self):
        self._set_headers()
        
    # GET sends back a Hello world message
    def do_GET(self):
        self._set_headers()
        self.wfile.write(json.dumps({'hello': 'world', 'received': 'ok'}))
        
    # POST echoes the message adding a JSON field
    def do_POST(self):
        ctype, pdict = cgi.parse_header(self.headers.getheader('content-type'))
        
        # refuse to receive non-json content
        if ctype != 'application/json':
            self.send_response(400)
            self.end_headers()
            return
            
        # read the message and convert it into a python dictionary
        length = int(self.headers.getheader('content-length'))
        message = json.loads(self.rfile.read(length))
        
        # add a property to the object, just to mess with data
        message['received'] = 'ok'
        
        # send the message back
        self._set_headers()
        self.wfile.write(json.dumps(message))
        
def run(server_class=HTTPServer, handler_class=Server, port=8008):
    server_address = ('', port)
    httpd = server_class(server_address, handler_class)
    
    print 'Starting httpd on port %d...' % port
    httpd.serve_forever()
    
if __name__ == "__main__":
    from sys import argv
    
    if len(argv) == 2:
        run(port=int(argv[1]))
    else:
        run()
        

thumbnail.png

Brilliant. Used it as the basis for a Multiprocess task broker which uses this example as the basis for its simple REST API.

https://gist.github.com/fahadysf/d80b99685ea3cfe3de4631f60e0136cc

When i run the server when i send the json i have this error:

httpmessage' object has no attribute 'getheader'

any help?

Sorry, I wrote this gist many years ago and I have no clue... Should self.headers be an httpmessage object though? Did you modify the code?

Or... maybe the libraries I used have been modified during these years, I don't know...

Thanks for writing this @nitaku it really helped me out.
If anyone is interested, self.header now has a get intead of getheader

length = int(self.headers.get('content-length'))
payload_string = self.rfile.read(length).decode('utf-8')
payload = json.loads(payload_string) if payload_string else None

@wanderer06 @nitaku thanks for all!

not working on Python 3 due to the following errors:

$ sudo pip3 install BaseHTTPServer
ERROR: Could not find a version that satisfies the requirement BaseHTTPServer (from versions: none)
ERROR: No matching distribution found for BaseHTTPServer

Thanks @nitaku for the example. I expanded it a little to provide Access-Control-Allow-Origin headers so that local development with XHRs from a browser don't get CORS errors, as well as updating for python3.

#!/usr/bin/env python3
"""An example HTTP server with GET and POST endpoints."""

from http.server import HTTPServer, BaseHTTPRequestHandler
from http import HTTPStatus
import json
import time


# Sample blog post data similar to
# https://ordina-jworks.github.io/frontend/2019/03/04/vue-with-typescript.html#4-how-to-write-your-first-component
_g_posts = [
    {
        'title': 'My first blogpost ever!',
        'body': 'Lorem ipsum dolor sit amet.',
        'author': 'Elke',
        'date_ms': 1593607500000,  # 2020 July 1 8:45 AM Eastern
    },
    {
        'title': 'Look I am blogging!',
        'body': 'Hurray for me, this is my second post!',
        'author': 'Elke',
        'date_ms': 1593870300000, # 2020 July 4 9:45 AM Eastern
    },
    {
        'title': 'Another one?!',
        'body': 'Another one!',
        'author': 'Elke',
        'date_ms': 1594419000000, # 2020 July 10 18:10 Eastern
    }
]


class _RequestHandler(BaseHTTPRequestHandler):
    # Borrowing from https://gist.github.com/nitaku/10d0662536f37a087e1b
    def _set_headers(self):
        self.send_response(HTTPStatus.OK.value)
        self.send_header('Content-type', 'application/json')
        # Allow requests from any origin, so CORS policies don't
        # prevent local development.
        self.send_header('Access-Control-Allow-Origin', '*')
        self.end_headers()

    def do_GET(self):
        self._set_headers()
        self.wfile.write(json.dumps(_g_posts).encode('utf-8'))

    def do_POST(self):
        length = int(self.headers.get('content-length'))
        message = json.loads(self.rfile.read(length))
        message['date_ms'] = int(time.time()) * 1000
        _g_posts.append(message)
        self._set_headers()
        self.wfile.write(json.dumps({'success': True}).encode('utf-8'))

    def do_OPTIONS(self):
        # Send allow-origin header for preflight POST XHRs.
        self.send_response(HTTPStatus.NO_CONTENT.value)
        self.send_header('Access-Control-Allow-Origin', '*')
        self.send_header('Access-Control-Allow-Methods', 'GET, POST')
        self.send_header('Access-Control-Allow-Headers', 'content-type')
        self.end_headers()


def run_server():
    server_address = ('', 8001)
    httpd = HTTPServer(server_address, _RequestHandler)
    print('serving at %s:%d' % server_address)
    httpd.serve_forever()


if __name__ == '__main__':
    run_server()

How to expand this to say a custom get request.
curl http://localhost:8009/get_all_configs

@mfickett : We also need to convert response to bytes as following. Without it we get error , TypeError: a bytes-like object is required, not 'str'

    def do_GET(self):
        self._set_headers()
        response = json.dumps({'hello': 'world', 'received': 'ok'})
        response = bytes(response, 'utf-8')
        self.wfile.write(response)

@saiprasad2210 : You get access to path as self.path inside handler. You can process it as you like. An example is here : https://github.com/gitvipin/sql30/blob/master/sql30/api.py#L45

in do_GET function:
this line is missing encoding to bytes object

self.wfile.write(json.dumps({'hello': 'world', 'received': 'ok'}))

should be:

self.wfile.write(json.dumps({'hello': 'world', 'received': 'ok'}).encode('utf-8'))

self.wfile.write(json.dumps({'hello': 'world', 'received': 'ok'}).encode('utf-8')) is incorrect — you have to encode the json itself, not the output. So this should actually be:
self.wfile.write(json.dumps({'hello': 'world', 'received': 'ok'}).encode('utf-8'))

@janzheng your second example is the same code as your first if I'm seeing correctly

self.wfile.write(json.dumps({'hello'

somehow I also missed the comment on Mar 24 by Alex. I'm going to excuse myself from this conversation hahah...