Foo bar

Running on Nginx

CGI

Here's an Nginx FastCGI configuration for Ubuntu based on the Arch Linux Wiki.

Install.

apt-get install fcgiwrap nginx

Configure the nginx site. (Try /etc/nginx/sites-enabled/default.)

location / {                                               
  fastcgi_param DOCUMENT_ROOT /var/www/dumptruck-web/;
  fastcgi_param SCRIPT_NAME dumptruck_web.py;
  fastcgi_param SCRIPT_FILENAME /var/www/dumptruck-web/dumptruck_web.py;
  fastcgi_pass unix:/var/run/fcgiwrap.socket;  
  
  # Fill in the gaps. This does not overwrite previous settings,
  # so it goes last
  include /etc/nginx/fastcgi_params;
 }

This depends on /var/www/dumptruck_web.py being a cgi script file that www-data can execute.

If you're installing this as part of cobalt, the configuration is

rewrite  ^\/([^\s/]+)\/sqlite\/?$  /$1/sqlite?box=$1;

location ~ ^\/([^\s/]+)\/sqlite\/?$ {
    fastcgi_param DOCUMENT_ROOT /var/www/dumptruck-web/;
    fastcgi_param SCRIPT_NAME dumptruck_web.py;
    fastcgi_param SCRIPT_FILENAME /var/www/dumptruck-web/dumptruck_web.py;

    # Fill in the gaps. This does not overwrite previous settings,
    # so it goes last
    include /etc/nginx/fastcgi_params;
    fastcgi_pass unix:/var/run/fcgiwrap.socket;
}

Specify some high number of processes in /etc/init.d/fcgiwrap like so.

FCGI_CHILDREN="9001"

You could also try something less extreme.

Then (re)start the daemons.

service fcgiwrap restart
service nginx restart

If this doesn't work, read /etc/init.d/fcgiwrap.

An example (simple) script would be

#!/usr/bin/env python

print '''HTTP/1.1 200
Content-Type: text/plain

Hello world
'''

An API call looks like this,

/jack-in-the/sqlite?q=SELECT+foo+FROM+baz

but the CGI script expects this,

/sqlite?q=SELECT+foo+FROM+baz&box=made-of-ticky-tacky

so the Nginx needs to rewrite the URL.

uWSGI

Here's a configuration based on the uWSGI quickstart

Also see uWSGI on nginx page, for reference but note that this explains a configuration that may be unnecessarily complicated.

Install these.

apt-get install uwsgi nginx uwsgi-plugin-{http,python}  

Run this (preferably as a daemon).

uwsgi \
  --plugins http,python \
  --wsgi-file foobar.py \
  --socket 127.0.0.1:3031 \
  --callable application \
  --processes 20

Use some high number of processes because they block.

We'll have to adjust the api script so that it works with uWSGI; once we do, add this to the nginx site. (Try /etc/nginx/sites-enabled/default.)

location /path/to/sqlite {
    include uwsgi_params;
    uwsgi_pass 127.0.0.1:3031;
}

Restart nginx.

service nginx restart

Test

curl localhost/path/to/sqlite?q=SELECT+42+FROM+sqlite_master&boxname=jack-in-the

An example (simple) script would be

def application(env, start_response):
    start_response('200 OK', [('Content-Type','text/html')])
    return "Hello World"

Add later

Gzip responses.

SQLite errors

The SQLite errors are normally pretty good, so an api call with that raises a SQLite error normally displays the error messages. This includes

• Locked databases
• Ungrammatical SQL

Some of these errors aren't great, like

• Database that the user doesn't have permission to read

We also treat some things as errors that SQLite doesn't:

• Databases that don't exist