I am looking to run standalone python scripts through fcgi for use with nginx, but I have no idea where to start with spawning the processes. Currently, I have PHP successfully with nginx+fcgi, but I'm unsure if/how I can do the same with python. Any suggestions on where to start?
See the python docs section on FCGI. Basically, with Python, you use the WSGI interface on top of an fcgi server which talks to the web server (the fcgi client).
See Python + FastCGI for a couple of Python fcgi servers.
Edit:
This nginx wiki page explains exactly how to set up Python with nginx using fcgi.
This wiki page describes the uWSGI module for nginx, which is the natural way to use Python with a web server, if you don't really need to use fcgi. This blog entry also looks like good info on uWSGI.
In production, Apache + mod_wsgi or Nginx + mod_wsgi? has some useful info for nginx mod_wsgi as well.
Related
I am a .net developer coming over to python. I have recently started using Flask and have some quick questions about serving files.
I noticed a lot of tutorials focused on nginix and flask. However, I am able to run flask without nginx. I'm just curious as to why this is used together (nginx and flask). Is nginx only for static files?
Nginx is a proxy server, imagine your apps have multiples microservices on differents languagues.
For more info NGINX REVERSE PROXY
On a development machine flask can be run without a webserver (nginx, apache etc) or an application container (eg uwsgi, gunicorn etc).
Things are different when you want to handle the load on a production server. For starters python is relatively very slow when it comes to serving static content where as apache / nginx do that very well.
When the application becomes big enough to be broken into multiple separate services or has to be horizontally scaled, the proxy server capabilities of nginx come in very handy.
In the architectures I build, nginx serves as the entry point where ssl is terminates and the rest of the application is behind a VPN and firewall.
Does this help?
From http://flask.pocoo.org/docs/1.0/deploying/ :
"While lightweight and easy to use, Flask’s built-in server is not suitable for production as it doesn’t scale well. Some of the options available for properly running Flask in production are documented here."
So from the Python/Flask docs, they both recommend not running the Flask web server as the production web server which makes sense. My question is, am I then able to run my Flask application on top of an Nginx server? Why do all the guides on the internet recommend wrapping Flask around uWSGI, Tornado, or some other WSGI server? What does it mean for something to be WSGI? Isn't Flask WGSI compliant?
I am particularly lost because here, the first response states:
Apache and Nginx are both HTTP servers.They can serve static files like
(.jpg and .html files) or dynamic pages (like a Wordpress blog or forum written in a language like PHP or Python).
However this post states:
Nginx is a web server. It serves static files, however it cannot execute and host
Python application. uWSGI fills that gap.
It just seems inefficient for my application to be handled by a server (ex: uWSGI) and then another server (ex: Nginx).
Nginx is a web server and is concerned with web server stuff, not with how to run Python programs. uWSGI is an application server and knows how to speak WSGI with Python (and other languages now). Both Nginx and uWSGI speak the uWSGI protocol, which is an efficient protocol over UNIX sockets.
Nginx deals with http requests from/responses to the outside world (possibly load balancing, caching, etc.). Your Flask application deals with WSGI requests/responses. uWSGI knows how to start your application (possibly with multiprocessing and/or threading) and bridge the gap between HTTP and WSGI.
There are other HTTP servers besides Nginx, and other WSGI servers besides uWSGI, but they all use the same workflow: the HTTP server passes to the WSGI server, which manages your application process and passes back to the HTTP server.
This setup is known as a reverse proxy. It allows each tool to do what it's good at and not be concerned about the other parts of the process. There is nothing particularly inefficient about it, until you get to truly massive scales.
Well, WSGI is a specification for interface between Python applications and web servers. uWSGI is (simply put) a realization of this specification written in C/C++. You can run almost any application on a "serious" webserver (like nginx) by just providing an entry point:
def application(env, start_response):
start_response('200 OK', [('Content-Type','text/html')])
return ["Hello World"]
and then running it like this:
uwsgi --http :9090 --wsgi-file file_with_the_code_above.py
You can return anything you want instead of ["Hello world"], of course. See http://uwsgi-docs.readthedocs.org/en/latest/WSGIquickstart.html for more.
I love python and I want to use python to construct my blog. I have deployed a nginx server and I find that in python wiki:
In addition to the above, some non-Python-based Web servers support
Python-based applications by embedding the Python virtual machine for
improved performance:
Nginx WSGI support module for Nginx HTTP server
I goto Nginx WSGI wiki page, but find:
mod_wsgi tested with Nginx 0.8.31 and python-2.6.2
My nginx version is 1.4.4(deployed one year before)...
I find a update information page in that wiki page, I click it hopefully:
Browser gives DNS look up error:ERR_NAME_NOT_RESOLVED
So, my question is:
mod_wsgi is out of date and is not good choice for python server?
If I want to use nginx as my http server, what is a better choice?
If I don't insist to use nginx, what is my best choice?
As I mentioned in my comment, the preferred way to deploy Python applications with nginx is to use it as a reverse proxy to a standalone Python WSGI server such as gunicorn or uwsgi.
The documentation for both projects includes sample configuration for running with nginx.
I'm new to linux development. I'm a bit confused on the documentation i read.
My ultimate goal is to host a simple python backed web service that would examine an incoming payload, and forward it to other server. This should be less than 30 lines of code in python.
I'm planning to use nginx to serve up python file. From my research, i also need a python web framework. I chose to go with uwsgi. I'm so confused. which one do I need? an nginx uwsgi module, or uwsgi server? i don't want to put django just for this simple purpose.
the nginx documentation mention that
Do not confuse the uwsgi protocol with the uWSGI server (that speaks the uwsgi protocol)
So, does that mean, i don't need to install uwsgi server separately? do i just install nginx, and start configuring? I'm using nginx 1.4.4
Could someone share a step by step configuration procedure on how to configure uwsgi with nginx, along with a sample python code(hello world maybe)? i can configure nginx just fine, but i don't know how to make it serve python pages. all the docs i could find involves having django on top.
You're mixing up things, so let me clarify.
Python's standard way of publishing applications via web servers is WSGI--you can think of it as a Python's native CGI. uWSGI is a WSGI-compliant server that uses uwsgi protocol to talk to other uWSGI instances or upstream servers. Usually the upstream server is nginx with HttpUwsgiModule that allows it to communicate using uwsgi protocol--with nginx you have additional layer of protection for your app server, load balancing and serving the static files. In most scenarios, You Should Be Using Nginx + UWSGI. To answer your question, uWSGI is installed and run separately from nginx, and they both need to be configured to communicate to each other.
Pure WSGI is pretty low-level, so you may want to use a WSGI-compliant framework. I guess the top two are Django and Flask.
For a hello world Flask setup, Serving Flask With Nginx seems to be a good article.
I am a PHP developer and am I want to use python for a project. What is the most common and simplest way to run python script on a server like apache or lighttpd? I am having trouble understanding how server languages that are not PHP or ASP run on servers.
In Python we have something called WSGI. But I believe this is too much for you right now. Grab a Python web framework, like Django. It comes with a web server and with good documentation on how to deploy it later. Play with it and things will start to clear up.
The longer version is that Python is a general purpose language - it's not designed for the web like PHP is. So you need a bit of work the get it to do web stuff and we already have some good frameworks for that (Django is the easiest to start with, so that is why I'm recommending it to you).
In general you should understand how the web works. It uses HTTP as a protocol for communication, which is build on top of the TCP stack, so a web application is just a server, that uses sockets (PHP has them as well as Python) and understands HTTP. Python comes with one build in - the SimpleHTTPServer, but it is not very good for production uses (it's great for development, though). This is why there are things like mod_wsgi (Python specific), FastCGI (general purpouse). Those things are basically ways for a real, production grade, web server (Apache, nginx) to talk to our python app and feed it the HTTP they get.
You can install gunicorn a Pure Python WSGI HTTP Server for UNIX. http://gunicorn.org/.
Typically, Apache is used with mod_python. See this mod_python tutorial