httpwatcher

Overview

httpwatcher is both a library and command-line utility for firing up a simple HTTP server to serve static files from a specific root path. Live reloading is triggered via web sockets.

Note that httpwatcher is intended for developers during testing of their static web sites, and is not at all intended as a production web server.

Requirements

In order to install httpwatcher, you will need:

• Python 2.7+ or Python 3.5+
• pip or easy_install

Installation

With your virtual environment active, run the following:

> pip install httpwatcher

To upgrade to the latest version of httpwatcher, simply:

> pip install -U httpwatcher

Usage

httpwatcher can either be used from the command line, or as a drop-in library within your own Python application.

Command-Line Usage

The quickest way to get up and running is to watch the current folder and serve your content from http://localhost:5555 as follows:

# Also opens your web browser at http://localhost:5555
> httpwatcher

# To get more help
> httpwatcher --help

With all possible options:

> httpwatcher --root /path/to/html \      # static root from which to serve files
              --watch "/path1,/path2" \   # comma-separated list of paths to watch (defaults to the static root)
              --host 127.0.0.1 \          # bind to 127.0.0.1
              --port 5556 \               # bind to port 5556
              --base-path /blog/ \        # serve static content from http://127.0.0.1:5556/blog/
              --verbose \                 # enable verbose debug logging
              --no-browser                # causes httpwatcher to not attempt to open your web browser automatically

Library Usage

Make sure httpwatcher is installed as a dependency for your Python project, and then:

import httpwatcher

# Just watch /path/to/html, and serve from that same path
httpwatcher.watch("/path/to/html")

Note that, unlike HttpWatcherServer, the httpwatcher.watch function automatically assumes that you want to open your default web browser at the base URL of the served site. To avoid this, do the following:

import httpwatcher

httpwatcher.watch("/path/to/html", open_browser=False)

To use the watcher server directly and have more control over the I/O loop:

from httpwatcher import HttpWatcherServer
from tornado.ioloop import IOLoop

def custom_callback():
    print("Web server reloading!")

server = HttpWatcherServer(
    "/path/to/html",                      # serve files from the folder /path/to/html
    watch_paths=["/path1", "/path2"],     # watch these paths for changes
    on_reload=custom_callback,            # optionally specify a custom callback to be called just before the server reloads
    host="127.0.0.1",                     # bind to host 127.0.0.1
    port=5556,                            # bind to port 5556
    server_base_path="/blog/",            # serve static content from http://127.0.0.1:5556/blog/
    watcher_interval=1.0,                 # maximum reload frequency (seconds)
    recursive=True,                       # watch for changes in /path/to/html recursively
    open_browser=True                     # automatically attempt to open a web browser (default: False for HttpWatcherServer)
)
server.listen()

try:
    # will keep serving until someone hits Ctrl+C
    IOLoop.current().start()
except KeyboardInterrupt:
    server.shutdown()

httpwatcher.watch takes mostly the same parameters as the constructor parameters for HttpWatcherServer (except, as mentioned earlier, for the open_browser parameter). It's just a convenience method provided to instantiate and run a simple HttpWatcherServer.

Inner Workings

httpwatcher makes extensive use of the Tornado asynchronous web framework to facilitate a combined asynchronous HTTP and WebSocket server. All HTML content served that contains a closing </body> tag will automatically have two <script> tags injected to facilitate the WebSockets connection back to the server.

The WebSockets endpoint is located at http://localhost:5555/httpwatcher by default, and the JavaScript file that facilitates the reloading is located at http://localhost:5555/httpwatcher.min.js by default (depending on your host and port settings).

Background

The library came out of a need for a simple web server, capable of serving static files with live reload capabilities, but also with the ability to serve content from non-standard base paths (for example, from http://somesite.com/blog/ as opposed to always just http://somesite.com). More specifically, this was to be used in Statik - the static web site generator.

The livereload library was great for a while, until the real need came up for modifying it, where the wheels came off the bus. More functional unit tests were needed to validate the basic functionality, and more flexibility was needed in some respects, so httpwatcher was built.

Contributing

Feel free to contribute! Fork the repository, make your changes in a feature branch, and then submit a pull request.

License

The MIT License (MIT)

Copyright (c) 2017 Thane Thomson

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.