https://pythonbasics.org

Python HTTP(S) Server — Example

Mar 20, 2016 13:17 · 913 words · 5 minute read Python

Python has built-in modules for creating HTTP servers, making it easy for developers to create web servers, serve static files, handle requests, and more.

The standard Python library has a built-in module that can be used as minimalistic HTTP/HTTPS web server. It provides support of the protocol and allows you to extend capabilities by subclassing.

Serve static HTML/CSS files to outside world can be very helpful and handy in many real life situations. For example, to show a client HTML pages you’ve created or stub an API by creating a static file.

Example of static Python HTTP server

Yet another purpose that static web server can serve is to create a dummy API by creating json or/and xml files. The structure of resources organized in sub-folders will provide RESTful-like URLs. E.g. /users/all.json.json may contain dummy records of users. This approach even faster then creating, for instance, a Flask application. No database required, works everywhere. To download data from a remote server. Let’s say there are some difficulties with scp command. It is possible to run simple server on the remote machine and download necessary contents via HTTP.

Python 3.x

python3 -m http.server 8000 --bind 127.0.0.1 

Python 2.x

python -m SimpleHTTPServer 8000

Python 2.x can only accept port as a parameter Bind address parameter is not available. Python 2.x Docs.

In both cases contents of the current folder will be accessible via http://127.0.0.1:8000

Example with SSL support

To run secure HTTPs server create a following module:

Python 3.x

from http.server import HTTPServer, BaseHTTPRequestHandler import ssl httpd = HTTPServer(('localhost', 4443), BaseHTTPRequestHandler) httpd.socket = ssl.wrap_socket (httpd.socket, keyfile="path/to/key.pem", certfile='path/to/cert.pem', server_side=True) httpd.serve_forever()

Python 2.x

import BaseHTTPServer, SimpleHTTPServer import ssl httpd = BaseHTTPServer.HTTPServer(('localhost', 4443), SimpleHTTPServer.SimpleHTTPRequestHandler) httpd.socket = ssl.wrap_socket (httpd.socket, keyfile="path/tp/key.pem", certfile='path/to/cert.pem', server_side=True) httpd.serve_forever()

To generate key and cert files with OpenSSL use following command

openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 365

Examples below will assume Python 3.5+ as an interpreter.

Advanced Python HTTP server

Let’s make our web server a little more advanced by handling requests.

do_GET

Consider the following code:

from http.server import HTTPServer, BaseHTTPRequestHandler class SimpleHTTPRequestHandler(BaseHTTPRequestHandler): def do_GET(self): self.send_response(200) self.end_headers() self.wfile.write(b'Hello, world!') httpd = HTTPServer(('localhost', 8000), SimpleHTTPRequestHandler) httpd.serve_forever()

This is a very trivial HTTP server that responds Hello, world! to the requester. Note, that self.send_response(200) and self.end_headers() are mandatory, otherwise the response wont be considered as valid. We can check that it actually works by sending a request using HTTPie:

$ http http://127.0.0.1:8000 HTTP/1.0 200 OK Date: Sun, 25 Feb 2018 17:26:20 GMT Server: BaseHTTP/0.6 Python/3.6.1 Hello, world!

Note, that self.wfile is a file like object, thus expects a byte-like objects to the write function. Another way of feeding the wfile is by using BytesIO object (see example below).

do_POST

Let’s handle a POST request now. Full example:

from http.server import HTTPServer, BaseHTTPRequestHandler from io import BytesIO class SimpleHTTPRequestHandler(BaseHTTPRequestHandler): def do_GET(self): self.send_response(200) self.end_headers() self.wfile.write(b'Hello, world!') def do_POST(self): content_length = int(self.headers['Content-Length']) body = self.rfile.read(content_length) self.send_response(200) self.end_headers() response = BytesIO() response.write(b'This is POST request. ') response.write(b'Received: ') response.write(body) self.wfile.write(response.getvalue()) httpd = HTTPServer(('localhost', 8000), SimpleHTTPRequestHandler) httpd.serve_forever()

The request body can be accessed via self.rfile . It is a BufferedReader so read([size]) method should be executed in order to get the contents. Note, that size should be explicitly passed to the function, otherwise the request will hang and never end.

This is why obtaining content_length is necessary. It could be retrieved via self.headers and converted into an integer. An example above just prints back whatever he receives, like follows:

http http://127.0.0.1:8000 key=value HTTP/1.0 200 OK Date: Sun, 25 Feb 2018 17:46:06 GMT Server: BaseHTTP/0.6 Python/3.6.1 This is POST request. Received:

You may consider to parse the JSON if you like.

Twisted As A Simple Web HTTP(S) Server

Another great example of a web server is Twisted. Clearly, it is much faster than one built in Python and provides lots of features out of the box. It supports SSL without a need to write a single line of code. It supports both Python 3.x and 2.x.

Installation

Usage

To run a twisted as a web server to serve current directory:

You will see the output like follows:

(.venv) andrey@work$ ~/Projects/test_app  twistd -no web --path=. 2016-10-23T19:05:02+0300 [twisted.scripts._twistd_unix.UnixAppLogger#info] twistd 16.4.1 (/Users/andrey/Projects/anvileight/.venv/bin/python3.5 3.5.1) starting up. 2016-10-23T19:05:02+0300 [twisted.scripts._twistd_unix.UnixAppLogger#info] reactor class: twisted.internet.selectreactor.SelectReactor. 2016-10-23T19:05:02+0300 [-] Site starting on 8080 2016-10-23T19:05:02+0300 [twisted.web.server.Site#info] Starting factory

Options

-n, –nodaemon don’t daemonize, don’t use default umask of 0077

-o, –no_save do not save state on shutdown

–path= is either a specific file or a directory to be set as the root of the web server. Use this if you have a directory full of HTML, cgi, epy, or rpy files or any other files that you want to be

Commands

web A general-purpose web server which can serve from a filesystem or application resource.

If you are looking for HTTPS and SSL support, consider the following options:

–https= Port to listen on for Secure HTTP.

-c, –certificate= SSL certificate to use for HTTPS. [default: server.pem]

-k, –privkey= SSL certificate to use for HTTPS. [default: server.pem]

Docker Example

Here are an example of Dockerfile I use to serve simple html pages to outside world.

FROM python:3.5 VOLUME ["/code"] ADD . /code WORKDIR /code EXPOSE 5000 CMD ["python", "-m", "http.server", "5000"]

It is possible to write custom handlers and extend the basic functionality. Including creating HTTPS server etc. Find official documentation for python 3 http server is here. Python 2 documentation is here

© Copyright 2023 Andrii Zarubin

Источник

Create a Python Web Server

A webserver in Python can be setup in two ways. Python supports a webserver out of the box. You can start a web server with a one liner.

But you can also create a custom web server which has unique functionality. In this article you’ll learn how to do that.

The web server in this example can be accessed on your local network only. This can either be localhost or another network host. You could serve it cross location with a vpn.

Example

Builtin webserver

That will open a webserver on port 8080. You can then open your browser at http://127.0.0.1:8080/

The webserver is also accessible over the network using your 192.168.-.- address.

This is a default server that you can use to download files from the machine.

Web server

Run the code below to start a custom web server. To create a custom web server, we need to use the HTTP protocol.

By design the http protocol has a “get” request which returns a file on the server. If the file is found it will return 200.

The server will start at port 8080 and accept default web browser requests.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
# Python 3 server example
from http.server import BaseHTTPRequestHandler, HTTPServer
import time

hostName = «localhost»
serverPort = 8080

class MyServer(BaseHTTPRequestHandler):
def do_GET(self):
self.send_response(200)
self.send_header(«Content-type», «text/html»)
self.end_headers()
self.wfile.write(bytes(««, «utf-8»))
self.wfile.write(bytes(«

Request: %s

« % self.path, «utf-8»))
self.wfile.write(bytes(««, «utf-8»))
self.wfile.write(bytes(«

This is an example web server.

«, «utf-8»))
self.wfile.write(bytes(««, «utf-8»))

if __name__ == «__main__»:
webServer = HTTPServer((hostName, serverPort), MyServer)
print(«Server started http://%s:%s» % (hostName, serverPort))

try:
webServer.serve_forever()
except KeyboardInterrupt:
pass

webServer.server_close()
print(«Server stopped.»)

If you open an url like http://127.0.0.1/example the method do_GET() is called. We send the webpage manually in this method.

The variable self.path returns the web browser url requested. In this case it would be /example

Python Decorators Introduction

Источник