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Bottle App gives Internal Server Error when accessing default page

I am just getting started with Bottle. I have a sample app on GitHub. The main module app.py (in the Application folder) looks like below
"""
This script runs the application using a development server.
"""
import bottle
import os
import sys
# routes contains the HTTP handlers for our server and must be imported.
import routes
if '--debug' in sys.argv[1:] or 'SERVER_DEBUG' in os.environ:
# Debug mode will enable more verbose output in the console window.
# It must be set at the beginning of the script.
bottle.debug(True)
def wsgi_app():
"""Returns the application to make available through wfastcgi. This is used
when the site is published to Microsoft Azure."""
return bottle.default_app()
if __name__ == '__main__':
PROJECT_ROOT = os.path.abspath(os.path.dirname(__file__))
STATIC_ROOT = os.path.join(PROJECT_ROOT, 'static').replace('\\', '/')
HOST = os.environ.get('SERVER_HOST', 'localhost')
try:
PORT = int(os.environ.get('SERVER_PORT', '5555'))
except ValueError:
PORT = 5555
#bottle.route('/static/<filepath:path>')
def server_static(filepath):
"""Handler for static files, used with the development server.
When running under a production server such as IIS or Apache,
the server should be configured to serve the static files."""
return bottle.static_file(filepath, root=STATIC_ROOT)
# Starts a local test server.
bottle.run(server='wsgiref', host=HOST, port=PORT)
The requirements.txt file has
bottle
gunicorn
as dependencies. I am using Python 3.7.2. After running pip install -r requirements.txt,
I ran python app.py. The server starts up and I can access the default page without error error
I tried running the server using gunicorn as below
gunicorn -w 2 -b 0.0.0.0:8080 app:wsgi_app
The server starts up fine, but when I access the default page, I get
Traceback (most recent call last):
File "/Users/<user>/Codebase/test-bottle/venv/lib/python3.8/site-packages/gunicorn/workers/sync.py", line 134, in handle
self.handle_request(listener, req, client, addr)
File "/Users/<user>/Codebase/test-bottle/venv/lib/python3.8/site-packages/gunicorn/workers/sync.py", line 175, in handle_request
respiter = self.wsgi(environ, resp.start_response)
TypeError: wsgi_app() takes 0 positional arguments but 2 were given
Please let me know what I've done wrong.

You can run the app without modifying the code using the “application factory” pattern (as stated in the gunicorn documentation):
gunicorn -w 2 -b 0.0.0.0:8080 'app:wsgi_app()'
Please note, that your page will not display fully, thought. The static links, e.g. css, will not load, since you are not defining any routes in your code in this case:
def wsgi_app():
"""Returns the application to make available through wfastcgi. This is used
when the site is published to Microsoft Azure."""
return bottle.default_app()

have you tried the following ?
from bottle import route, run, static_file
#route('/')
def index():
return '<h1>Hello Bottle!</h1>'
#bottle.route('/static/<filepath:path>')
#route("/static//<filepath:re:.*")
def server_static(filepath):
"""Handler for static files, used with the development server.
When running under a production server such as IIS or Apache,
the server should be configured to serve the static files."""
return bottle.static_file(filepath, root=STATIC_ROOT)
if __name__ == "__main__":
run(host='localhost', port=5555)
app = bottle.default_app()
then in a console :
gunicorn -w 4 your_app_name:app

Allow urls containing "www." on openshift hosted website

I have a (very) simple flask app hosted on open-shift.
It has one route:
#app.route('/')
def display_content():
return render_template("content.html.jnj2")
and a simple wsgi file (as described in the open-shift flask setup tutorial):
from wsgiref.simple_server import make_server
httpd = make_server('localhost', 8051, application)
httpd.serve_forever()
This works fine when I navigate to "myappname-mydomain.rhcloud.com", but gives an "ERR_NAME_NOT_RESOLVED" when I navigate to "www.myappname-mydomain.rhcloud.com".
I've done some googling etc, can't see anyone else with a similar problem.. I'm not aware of having changed any open-shift settings or anything.

Your app-domain.rhcloud.com address that is provided by OpenShift does NOT include a cname for www.app-domain.rhcloud.com, that's why it's not working. You can use your app-domain.rhcloud.com, or you can map your own alias like example.com or www.example.com using this guide: https://developers.openshift.com/en/managing-domains-ssl.html#using-a-custom-domain

How to get apache to serve static files on Flask webapp

I'm getting a 500 internal error while trying to get Apache to serve my static files.
The application will be locally hosted (not www facing). There will be no DNS to resolve a 'www.domain.com' name. I want to be able to access the application by entering the IP address of the server when I'm on that network.
This is my httpd.conf file (I'm on RHEL):
<Directory /var/www/testapp>
Order allow,deny
Allow from all
</Directory>
WSGIScriptAlias / /var/www/testapp/service.wsgi
If I change the WSGIScriptAlias to WGSIScriptAlias /test /var/www/testapp/service.wsgi then I can view my static files when I type in the IP, but I still can't access the service.py script from [IP]/test.
In any case, I want to be able to service all GET/POST requests with the service.py script so I want my alias to start at /, not some other place.
All my static files are in /var/www/html (Apache was automatically displaying these files before I messed with the httpd.conf, now I'm just getting a 500).
This is my service.wsgi:
import sys
sys.path.insert(0, '/var/www/testapp')
from service import app as application
This is my service.py:
from flask import Flask
app = Flask(__name__)
#app.route("/")
def hello(environ, start_response):
status = '200 OK'
output = "Hello"
response_headers = [('Content-type', 'text/plain'), ('Content-length', str(len(output)))]
start_response(status, response_headers)
return output
if __name__=='__main__'
app.run()
Do I need keep my .wsgi files in the /var/www/html directory as well? Or can they go in a different folder? I can see that there might be some conflict between the message I am sending to the server ('Hello') and the static files that are already in the /var/www/html/ directory. That's why I tried setting the alias to /test but that didn't work either.
I just want my Flask application to service GET/POST requests and want apache to serve all the static files.

Fixing the 500 errors
You are currently getting 500 errors because your handler is a basic WSGI handler, but Flask handlers are not WSGI handlers (Flask / Werkzeug abstracts all that for you). Change your handler to:
#app.route("/")
def hello():
return "Hello"
and the 500 errors should go away.
Serving static files with Apache
The following techniques can be used when your application is serving the root of the domain (/), depending on whether you are using WSGIScriptAlias or AddHandler.
When using WSGIScriptAlias
When using the WSGIScriptAlias to mount a WSGI application at / you can use an Apache Alias directive to ensure that certain sub-routes are not handled by WSGIScriptAlias (this is further documented in mod_wsgi's wiki as well):
Alias "/static/" "/path/to/app/static/"
<Directory "/path/to/app/static/">
Order allow,deny
Allow from all
</Directory>
If you also want to support blueprint static folders as well you'll also need to use the AliasMatch directive:
AliasMatch "(?i)^/([^/]+)/static/(.*)$" "/path/to/app/blueprints-root/$1/static/$2"
<Directory ~ "/path/to/app/blueprints-root/[^/]+/static/.*">
Order allow,deny
Allow from all
</Directory>
See also: The Directory directive.
When using AddHandler
As Graham Dumpleton has pointed out in the comments, you can use mod_rewrite to pass requests off to Python if and only if a file does not exist in DocumentRoot. Quoting from the linked docs:
When using the AddHandler directive, with WSGI applications identified by the extension of the script file, the only way to make the WSGI application appear as the root of the server is to perform on the fly rewriting of the URL internal to Apache using mod_rewrite. The required rules for mod_rewrite to ensure that a WSGI application, implemented by the script file 'site.wsgi' in the root directory of the virtual host, appears as being mounted on the root of the virtual host would be:
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.*)$ /site.wsgi/$1 [QSA,PT,L]
Do note however that when the WSGI application is executed for a request the 'SCRIPT_NAME' variable indicating what the mount point of the application was will be '/site.wsgi'. This will mean that when a WSGI application constructs an absolute URL based on 'SCRIPT_NAME', it will include 'site.wsgi' in the URL rather than it being hidden. As this would probably be undesirable, many web frameworks provide an option to override what the value for the mount point is. If such a configuration option isn't available, it is just as easy to adjust the value of 'SCRIPT_NAME' in the 'site.wsgi' script file itself.
from your.app import app # Your Flask app
import posixpath
def application(environ, start_response):
# Wrapper to set SCRIPT_NAME to actual mount point.
environ['SCRIPT_NAME'] = posixpath.dirname(environ['SCRIPT_NAME'])
if environ['SCRIPT_NAME'] == '/':
environ['SCRIPT_NAME'] = ''
return app(environ, start_response)
This wrapper will ensure that 'site.wsgi' never appears in the URL as long as it wasn't included in the first place and that access was always via the root of the web site instead.

How can I use a single server to deploy multiple WSGI apps on multiple domains?

Hypothetical
I've got a Linux VPS server named myserver, mounted at myserver.com.
On this server I have two Flask WSGI apps app-one and app-two.
I'd like to deploy these two apps on myserver, but I want them mounted on the domains app-one.com and app-two.com.
The apps have no external dependencies (no databases, caches, etc). They're stand-alone, single-file apps.
I do not have Apache, NGinX or any other webserver software installed; just Python, Flask and two WSGI apps.
I have Python/Flask experience, but I don't have a lot of experience with WSGI deployment or multiple-domain work. Basic instructions and/or reading material appreciated.
Question / TL;DR
How can I use a server mounted at one domain to deploy two WSGI apps to two domains? Do I need to install software especially for this case, or is it just a matter of pointing the apps at my chosen domains?
Thank you for any and all advice.

Once you have DNS set up to point both app-one.com and app-two.com to myserver.com's IP address then you need to set up something to route requests coming in on port 80 (or 443 if you are going to use SSL) to each of your apps. This is normally done with virtual hosts in Apache or nginx.
If you need to run both applications in the same Python process (whether you are using a non-Python webserver as your application container or not) then you will need to dispatch to each of your apps by hand:
from werkzeug.exceptions import NotImplemented
from werkzeug.wsgi import get_host
class DomainDispatcher(object):
"""Simple domain dispatch"""
def __init__(self, domain_handlers, default_handler=None):
self.domain_handlers = domain_handlers
self.default_handler = domain_handlers.get("default", default_handler)
if self.default_handler is None:
self.default_handler = NotImplemented()
def __call__(self, environ, start_response):
host = get_host(environ)
handler = self.domain_handlers.get(host, self.default_handler)
return handler(environ, start_response)
An example of usage:
from app_one import app as app1
from app_two import app as app2
from domain_dispatcher import DomainDispatcher
dispatcher = DomainDispatcher({'app-one.com': app1, 'app-two.com': app2})
if __name__ == '__main__':
# Wrap dispatcher in a WSGI container
# such as CherryPy

Running Tornado in apache

My end goal is to implement a WebSocket server using python.
I'm accomplishing this by importing tornado in my python scripts. I've also installed mod_wsgi in apache, and their script outputs Hello World!, so WSGI seems to be working fine. Tornado is also working fine as far as I can tell.
The issue comes when I use tornado's wsgi "Hello, world" script:
import tornado.web
import tornado.wsgi
import wsgiref.simple_server
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.write("Hello, world")
if __name__ == "__main__":
application = tornado.wsgi.WSGIApplication([
(r"/", MainHandler),
])
server = wsgiref.simple_server.make_server('', 8888, application)
server.serve_forever()
First, I get a 500 error and the log tells me WSGI can't find 'application'.
So I remove if __name__ == "__main__", and the page loads infinitely.
I assume this is because of server.serve_forever() so I removed it in an attempt to see Hello, world
But now I just get 404: Not Found. It's not my apache 404 page, and I know that the server can find my main .wsgi file...

You can't use websockets with Tornado's WSGIApplication. To use Tornado's websocket support you have to use Tornado's HTTPServer, not apache.

The WSGIApplication handlers are relative to the webserver root. If your application url is /myapp, your 'application' must look like this:
application = tornado.wsgi.WSGIApplication([
(r"/myapp", MainHandler),
(r"/myapp/login/etc", LoginEtcHandler),
])
Oh, and it seems like the documentation is shit (as usual) and __name__ will look something like this when running under apache: _mod_wsgi_8a447ce1677c71c08069303864e1283e.
So! a correct "Hello World" python script will look like this:
/var/www/wsgi-scripts/myapp.wsgi:
import tornado.web
import tornado.wsgi
import wsgiref.simple_server
class MainHandler(tornado.web.RequestHandler):
def get(self):
self.write('Hello World')
application = tornado.wsgi.WSGIApplication([
(r"/myapp", MainHandler),
])
And in the apache config (not .htaccess):
WSGIScriptAlias /myapp /var/www/wsgi-scripts/myapp.wsgi

To use tornado in apache,add a mod-wsgi plugin to apache.
apt-get install libapache2-mod-wsgi
Write a tornado wsgi server with
.wsgi
NOTE:Dont use__name__
Configure the apache.conf to run your server.To configure use this mod-wsgi guide

If you still want to combine them both, you can use Apache as a proxy that will just be the 1st point in front of the user - but actually reroute the traffic to your local Tornado server ( In / Out )
In my case for example, my Apache listen in port 443 ( some default config )
Then I run my tornado in port 8080, and given a path - will redirect
#File: conf.d/myapp.conf
<VirtualHost *:80>
ErrorLog "logs/myapp_error_log"
ProxyPreserveHost On
ProxyRequests off
ProxyPreserveHost On
<Proxy *>
Require all granted
</Proxy>
RewriteEngine on
RewriteCond %{REQUEST_METHOD} ^TRACE
RewriteRule .* - [F]
ProxyPassMatch "/myapp/(.*)" "http://localhost:8080/myapp/$1"
ProxyPassReverse "/myapp/" "http://localhost:8080/myapp/"
</VirtualHost>
If you're using RedHat "family" OS also turn on the ability to forward network connections:
setsebool -P httpd_can_network_connect 1