Bottle.py is a magnificent that pretty much lets you forget you’re working with the web. Coupled with Nginx, it becomes very easy to design custom web services.
Maybe it’s not that easy, but it’s worth checking out! I’m going to take you through the process of getting this amazing stack going. Let’s get started!
Installing Stuff
I’m going to be assuming the use of Debian. It’s easy enough to adjust.
aptitude install uwsgi uwsgi-plugin-python python-bottle nginx
Your First Bottle Application
I tend to start with a basic structure:
/var/www/webapp/
plugins/
__init__.py
static/
css/
files/
images/
js/
views/
base.tpl
page.tpl
app.py
Whether I have anything in the directories or not, they exist. It’s just how I make sure I keep things consistent across applications.
A basic skeleton of app.py will look something like this:
#!/usr/bin/python
'''
A basic bottle app skeleton
'''
import bottle
app = application = bottle.Bottle()
@app.route('/static/<filename:path>')
def static(filename):
'''
Serve static files
'''
return bottle.static_file(filename, root='./static')
@app.route('/')
def show_index():
'''
The front "index" page
'''
return 'Hello'
@app.route('/page/<page_name>')
def show_page(page_name):
'''
Return a page that has been rendered using a template
'''
return template('page', page_name=page_name)
class StripPathMiddleware(object):
'''
Get that slash out of the request
'''
def __init__(self, a):
self.a = a
def __call__(self, e, h):
e['PATH_INFO'] = e['PATH_INFO'].rstrip('/')
return self.a(e, h)
if __name__ == '__main__':
bottle.run(app=StripPathMiddleware(app),
server='python_server',
host='0.0.0.0',
port=8080)
I realize there’s a bit going on here, but it’s not a minimal skeleton. This shows you how to serve static content, a basic text only front page, and a templated page. While you’re testing, you don’t want that slash unless the main page is being requested. Browsers seem to like adding that. It’s not an issue when we get to deployment because uwsgi will take car of that for you.
Notice that bottle.run() only happens when you run app.py. It won’t run when you launch it as an application with uwsgi. This chunk is also the only place that we call StripPathMiddleware. If you have no need for development, then you can remove the last two chunks of code.
Try it out: python app.py
You’ll see the application start running. Go to example.com:8080/. Neat, huh?
The Templating System
Bottle has a bunch of templating options. For now, we’re only going to touch the most basic option.
views/page.tpl:
You are visiting {{page_name}}!
%rebase base
views/base.tpl:
<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
<title>My Site!</title>
</head>
<body>
<div id="pagebody">
%include
</div>
</body>
</html>
This is obviously very basic, but it will get you started. Check out the Bottle Docs for more information. The templating options are endless!
Now that you have this done, restart app.py and visit example.com:8080/page/foo.
You should be seeing a rather blank looking page that says “You are visiting
foo” with the title “My Site!”
Adding UWSGI
Now that we have a very basic bottle application, it’s time to fit it into the stack. The built in web server that bottle offers is very slow. It’s for development only. Don’t ever expect to use it in production.
app = application = bottle.Bottle()
This little gem is more magic than you think. Don’t forget it!
The UWSGI configuration is pretty simple. See the UWSGI Docs for more details information.
Edit /etc/uwsgi/apps-available/bottle.ini:
[uwsgi]
socket = /run/uwsgi/app/bottle/socket
chdir = /var/www/bottle
master = true
plugins = python
file = app.py
uid = www-data
gid = www-data
Then add a symlink from apps-enabled::
ln -s /etc/uwsgi/apps-available/bottle.ini /etc/uwsgi/apps-enabled/bottle.ini
And restart the service::
service uwsgi restart
At this point you’ll see a socket file created at /run/uwsgi-bottle.socket. That’s great, but we need to actually make use of it.
Adding Nginx
I prefer using the conf.d/ directory for my configurations. You can do as you wish on your server.
Edit /etc/nginx/conf.d/bottle.conf:
upstream _bottle {
server unix:/run/uwsgi/app/bottle/socket;
}
server {
listen [::]:80;
listen 80;
server_name deb.ngx.cc;
root /var/www/bottle;
location / {
try_files $uri @uwsgi;
}
location @uwsgi {
include uwsgi_params;
uwsgi_pass _bottle;
}
}
In our bottle application, we defined a route for static content. However, it’s
better to have nignx serve this data so that we can avoid making python do any
work. That’s why we use try_files in the location block. You want that in
your bottle application for development, but when we deploy, it won’t actually
get used.
Then restart the service: service nginx restart
You’ll now be able to access your bottle application from the internet through nginx.
Final Thoughts
This was a very brief tutorial. It’s meant only to get you jump started into having a usable bottle+uwsgi+nginx stack that you can expand on to fit your environment/needs. If you feel any parts need additional explanation, please let me know!