Getting Started¶

Overview
Creating a server
The first website

Overview¶

Slowdown is a coroutine-based Python web framework based on gevent. Slowdown is written in pure Python and supports Python 3.6+.

# file: mysite/__cgi__/index_html.py

def GET(rw):
    rw.send_html_and_close(content='<html>Hello, World!</html>')

Creating a server¶

You can use virtualenv to create a server by the following commands.

$ virtualenv --python=/usr/bin/python3 myproj
$ myproj/bin/pip3 install slowdown
$ myproj/bin/slowdown --init
Initialize a project in /PATH/TO/myproj? [Y/n]: Y
Creating myproj/bin ... exists
Creating myproj/etc ... exists
Creating myproj/var ... done
Creating myproj/pkgs ... done
Creating myproj/var/log ... done
Creating myproj/bin/slowdown ... exists
Creating myproj/etc/slowdown.conf ... done
DONE! Completed all initialization steps.

Let’s look at what virtualenv and slowdown --init created.

myproj/
    bin/
        slowdown
    etc/
        slowdown.conf
    lib/
    var/
    pkgs/

Start the slowdown server:

$ myproj/bin/slowdown -vv
Serving HTTP on 0.0.0.0 port 8080 ...

The first website¶

Web sites are placed in the pkgs dir as regular python packages and sometimes has the following structure:

myproj/
    pkgs/
        mysite/
            __init__.py
            __www__/
            __cgi__/

Static files in the __www__ dir shall be sent to the browser. And scripts in the __cgi__ dir will be executed when requested.

So, you can create a python package as a container for site resources.

$ mkdir myproj/pkgs/mysite
$ touch myproj/pkgs/mysite/__init__.py
$ mkdir myproj/pkgs/mysite/__www__
$ mkdir myproj/pkgs/mysite/__cgi__

And add a script named index.html.py to the __cgi__ folder.

# file: myproj/pkgs/mysite/__cgi__/index_html.py

def HTTP(rw):
    rw.send_html_and_close(content='<html>Hello, World!</html>')

The index.html file in the __www__ folder gives the same effect:

<!-- file: myproj/pkgs/mysite/__www__/index.html -->

<html>Hello, World!</html>

Then edit the config file myproj/etc/slowdown.conf :

<routers>
    <router DEFAULT>
        pattern ^(?P<ALL_HOST>.*)$$
        <host ALL_HOST>
            pattern ^(?P<ALL_PATH>/.*)$$
            <path ALL_PATH>
                handler mysite
            </path>
        </host>
    </router>
</routers>
<servers>
    <http MY_HTTP_SERVER>
        address 0.0.0.0:8080
        router  DEFAULT
    </http>
</servers>

Now you’ve got a minimized website. You can start the web server by the following command:

$ myproj/bin/slowdown -vv
Serving HTTP on 0.0.0.0 port 8080 ...

Browse http://127.0.0.1:8080/ and you’ll see the Hello, World! page.