Setting up nginx with Bottle and Flup (FastCGI)

Writing the bottle app

from bottle import route, run

@route('/app/')
def hello_name(name):
    return "Hello " + name

run(server="flup" host='localhost', port=8080)

Again, two things are important here.

1. We got to have the routing correct
2. We have to set the server = “flup”

Using flup

What is flup? Flup is a random assortment of WSGI server and most importantly for us, fcgi. You can install it with pip:

pip install flup

Now we can run our application with flup.

Installing and configuring nginx

If you’re running a Debian-based distribution it’s just:

sudo apt-get install nginx

Start by making a backup copy of the nginx.conf which is in /etc/nginx/:

cp /etc/nginx/nginx.conf .

Now we can edit it and connect it to our bottle application.

Setting nginx up for fast cgi

The basic structure in nginx’s config files is:

http {
    server {
        location {
        }
}

in server {} comes everything related to the servers, e.g. ports and host names. In location /foobar {} you insert everything to related a location – in this case /foobar.

Configuring a server

We start with the following code:

server {
    listen 8080;
    
    location / {
        root /home/foobar/www;
    }
    
    location /app/ {
        # magic
    }
}

This creates a server which runs on port 8080. Furthermore, we apply rules to two locations. First / to which we assign /home/foobar/www. That means that every request at / will request files / paths in /home/foobar/www. Some examples:

http://location:8080/ -> /home/foobar/www
http://location:8080/test -> /home/foobar/www/test
http://location:8080/test.html -> /home/foobar/www/test.html
http://location:8080/some/directory/baz.html -> /home/foobar/www/some/directory/baz.html

However, we defined an exception: /app/. We want to use fastcgi in this case. nginx offers this ability natively. You just write the following:

    location /queue/ {
            fastcgi_pass   localhost:8889;
            fastcgi_param  GATEWAY_INTERFACE  CGI/1.1;
            fastcgi_param  SERVER_SOFTWARE    nginx;
            fastcgi_param  QUERY_STRING       $query_string;
            fastcgi_param  REQUEST_METHOD     $request_method;
            fastcgi_param  CONTENT_TYPE       $content_type;
            fastcgi_param  CONTENT_LENGTH     $content_length;
            fastcgi_param  SCRIPT_FILENAME     $document_root$fastcgi_script_name;
            fastcgi_param  SCRIPT_NAME        $fastcgi_script_name;
            fastcgi_param  REQUEST_URI        $request_uri;
            fastcgi_param  DOCUMENT_URI       $document_uri;
            fastcgi_param  DOCUMENT_ROOT      $document_root;
            fastcgi_param  SERVER_PROTOCOL    $server_protocol;
            fastcgi_param  REMOTE_ADDR        $remote_addr;
            fastcgi_param  REMOTE_PORT        $remote_port;
            fastcgi_param  SERVER_ADDR        $server_addr;
            fastcgi_param  SERVER_PORT        $server_port;
            fastcgi_param  SERVER_NAME        $server_name;
        }

It’s a lot of lines but the first one is the one you have to edit. It says that fastcgi requests should be forwarded to localhost:8889 which, in this case, is our bottle application. You can put the rest into an extra file and use include file to include it.

Starting nginx and bottle

First, we want to start our nginx server:

sudo nginx # or if we want to use a special config file
sudo nginx -c /path/to/nginx.conf

If that runs, we just start our bottle app and we’re done.

python bottle.py