nxweb + Python Flask Configuration


Quick start

Here is our Flask application:


from flask import Flask
app = Flask(__name__)

def hello():
  return "Hello Flask!"

Make sure there is no nxweb_config.json file in current directory and launch nxweb:

nxweb -T python -W hello.app

In case you have Flask installed in virtualenv environment ./env you can specify path to that environment like this:

nxweb -T python -W hello.app -V env

Now point your browser at http://localhost:8055/

Production deployment

In production we are going to use more functional configuration.

Directory layout

current working directory/
  |- nxweb_config.json
  |- python/
  |- |- hello.py
  |- env/
  |- static/
  |- cache/
  |- logs/

python directory shall contain Python files of our application.

env directory contains Python virtual environment where we have Flask installed (this is optional).

static directory shall contain static files like *.js*.css, images, etc.

cache directory will be used by nxweb to store cached files (you might need to periodically clean this directory by removing files of certain age).

logs directory will contain nxweb log files.

Make sure file permissions allow nxweb to write into cache and logs directories.


      "virtualenv_path":"env", // this is optional
      "project_path":"python", // python module search root; relative to workdir
      "wsgi_application":"hello.app" // full python name of WSGI entry point


    { // first check static files
      "prefix":null, // "vhost":".mydomain.com",
      "handler":"sendfile", "memcache":false,
      "charset":"utf-8", // charset for text files
      "index_file":"index.htm", // directory index
        {"type":"gzip", "compression":4, "cache_dir":"cache/gzip"}

    { // then fallback to python
      "prefix":null, // "vhost":".mydomain.com",
      "handler":"python", // "uri":"/my/path/info",
      "dir":"cache/upload_temp", "size":50000000 /* 50Mb max upload */,
        {"type":"file_cache", "cache_dir":"cache/python"}

Launch nxweb

Make sure your current working directory is where nxweb_config.json file is located.

nxweb -H :80 -S :443 -l logs/nxweb_error_log -a logs/nxweb_access_log

This must be run by a privileged user (root) in order to use port numbers below 1024. If you specify -u <user> -g <group> options then nxweb will drop privileges after binding the ports.

Now you should be able to access your application under site's root directory. Static files will be checked first, then request will be routed to Python.

There is a filter applied to Python's output in this sample config:

  • file_cache will cache responses (only when they contain Last-Modified header)