noolt is an web application server with REAL and QUICK reloading, like in PHP
(noolt actually spawns new processes for each application). Reloading isn't
as simple as you could think - see here
for information from Python developers that started me on this quest.
Go into some directory, where you would be creating your "apps", like ~/web/:
Install noolt via install script:
wget https://gist.github.com/raw/973294/6c64fa70018c9466b69ec39608b6de4f50a5/noolt-install.sh -O - | bash
After installing noolt, run from console (terminal):
mkdir ~/web/
cd ~/web/
python -m noolt.serve
Create file ~/web/app1/index.py (mkdir ~/web/app1 && gedit ~/web/app1/index.py) with these contents:
hosts = "127.0.0.1:8091",
def index(r):
print "Hello, World"
Go to http://127.0.0.1:8091/ in your browser. Change something in ~/web/app1/index.py
and see it instantly reload. By default noolt is configured to check for reloading
only at most 3 times per second, which is fast enough to be used in most
production installations. See below on how to change it.
Via install script:
wget https://gist.github.com/raw/973294/6c64fa70018c9466b69ec39608b6de4f50a5/noolt-install.sh -O - | bash
Or by hand:
git clone git://github.com/yappie/noolt.git noolt
cd noolt
sudo python setup.py install
cd ..
sudo rm -rf noolt
What this does is looks for new directories that have index.py in them, then
it scans for hosts variable and starts http servers accordingly. You might
need super-user rights to run on port 80 (default http port).
Quick example server.py (this is most of what python -m noolt.serve
does for you).
from noolt.app import App
import time
app = App('hello_world.py')
app.set_reload_intervals(.3) # reload AT MOST ~3 times per second
time.sleep(1000000000)
hello_world.py
hosts = ("127.0.0.1:8091",)
def index(r):
print "Hello, World"
Run:
python server.py
Then make changes to hello_world.py and instantly see changes appear.
hosts define host and port which the application will respond (you can change
those "on-fly") and even have many hosts/ports for each application.
I haven't developed noolt in quite some time, but I feel it might be useful.
noolt uses CherryPy's excellent WSGI server.
File upload not wrapped yet, but it's somewhere in the r variable.
Variable that gets sent to index function is like this:
r.wsgi = {
'ACTUAL_SERVER_PROTOCOL': 'HTTP/1.1',
'HTTP_ACCEPT': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
'HTTP_ACCEPT_CHARSET': 'windows-1251,utf-8;q=0.7,*;q=0.3',
'HTTP_ACCEPT_ENCODING': 'gzip,deflate,sdch',
'HTTP_ACCEPT_LANGUAGE': 'ru-RU,ru;q=0.8,en-US;q=0.6,en;q=0.4',
'HTTP_CACHE_CONTROL': 'max-age=0',
'HTTP_CONNECTION': 'keep-alive',
'HTTP_COOKIE': '....',
'HTTP_HOST': '127.0.0.1:8091',
'HTTP_USER_AGENT': 'Mozilla/5.0 (X11; Linux i686) AppleWebKit/534.27 (KHTML, like Gecko) Chrome/12.0.712.0 Safari/534.27',
'PATH_INFO': '/',
'QUERY_STRING': '',
'REMOTE_ADDR': '127.0.0.1',
'REMOTE_PORT': '46824',
'REQUEST_METHOD': 'GET',
'SCRIPT_NAME': '',
'SERVER_NAME': 'localhost',
'SERVER_PORT': '8091',
'SERVER_PROTOCOL': 'HTTP/1.1',
'SERVER_SOFTWARE': 'CherryPy/3.1.2 WSGI Server',
'wsgi.multiprocess': False,
'wsgi.multithread': True,
'wsgi.run_once': False,
'wsgi.url_scheme': 'http',
'wsgi.version': [1, 0]
}
so you can refer to those like this: r.wsgi['HTTP_HOST']
Currently this can only be done via "low level" (see above) by setting:
def quiet_traceback(traceback_text):
return ""
app.reformat_traceback = quiet_traceback
Basically reformat_traceback receives text representation of traceback
Most of production environment could use usual noolt reloading (i.e. just plain python -m noolt.serve), here is a more
strict version, that uses flag file to detect when to reload (redefine is_production
yourself somehow):
from noolt.app import App
import time, os
is_production = True if os.path.exists('.production') else False
app_filename = 'hello_world.py'
reload_flag_filename = '.reload'
app = App(app_filename)
if is_production:
app.set_reload_intervals(-1) # do not reload
app.reformat_traceback = lambda x: True # suppress tracebacks
# (good idea would be to use logging module for tracebacks)
while 1:
if os.path.exists(reload_flag_filename):
os.unlink(reload_flag_filename)
app.mark_processes_for_reload()
time.sleep(1)
else:
app = App(app_filename)
app.set_reload_intervals(.3)
time.sleep(1000000000)