Auto reloading is not working in Bottle framework - python

I am currently getting started with Bottle framework (doing the Hello World example and afterwards have to build a RESTful API). The problem is the fact that reloader doesn't work. When I make a change in the code and reload the page where the change should show nothing happens. It works on my friends' computers so I'm am a bit confused.
Using python 2.7.
from bottle import route, run
#route('/hello')
def hello():
return "Hello World!"
run(host='localhost', port=8080, debug=True, reloader =True)
EDIT:Also what i noticed is that when i save the change in the script while the server is still listening i get this:
----------------------------------------
Exception happened during processing of request from ('127.0.0.1', 60472)
Traceback (most recent call last):
File "C:\Python27\lib\SocketServer.py", line 290, in _handle_request_noblock
self.process_request(request, client_address)
File "C:\Python27\lib\SocketServer.py", line 318, in process_request
self.finish_request(request, client_address)
File "C:\Python27\lib\SocketServer.py", line 331, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "C:\Python27\lib\SocketServer.py", line 652, in __init__
self.handle()
File "C:\Python27\lib\wsgiref\simple_server.py", line 116, in handle
self.raw_requestline = self.rfile.readline(65537)
File "C:\Python27\lib\socket.py", line 480, in readline
data = self._sock.recv(self._rbufsize)
KeyboardInterrupt
----------------------------------------

There is an interesting clue if you use Windows OS:
Keep in mind that in windows this must be
under if name == "main": due to the way the multiprocessing
module works.
So it should look like this
from bottle import route, run
#route('/hello')
def hello():
return "Hello World!"
if __name__ == "__main__":
run(host='localhost', port=8080, debug=True, reloader=True)

Related

GAE/Flask [Errno 13] Permission denied

As the title suggests, I am seeing this error when my flask app tries to run.
I am hosting the application locally using dev_appserver.
The error occurs when I visit the site and it tries to run the app. It appears that GAE is trying and failing to bind a socket for some reason.
I suspect that this may have something to do with OAuth2. Maybe it requires an SSL connection?
I don't even know where to begin solving this as none of the other posts about this are experiencing the same variation of the issue.
Edit: Here's a screenshot of the console confirming that the GAE server launches successfully on a different port; still doesn't resolve it
Traceback (most recent call last):
File "C:\Users\XXX\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\runtime\wsgi.py", line 240, in Handle
handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
File "C:\Users\XXX\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\runtime\wsgi.py", line 299, in _LoadHandler
handler, path, err = LoadObject(self._handler)
File "C:\Users\XXX\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\runtime\wsgi.py", line 85, in LoadObject
obj = __import__(path[0])
File "C:\Users\XXX\PycharmProjects\ad-assignment\main.py", line 51, in <module>
app.run()
File "C:\Users\XXX\PycharmProjects\ad-assignment\lib\flask\app.py", line 843, in run
run_simple(host, port, self, **options)
File "C:\Users\XXX\PycharmProjects\ad-assignment\lib\werkzeug\serving.py", line 694, in run_simple
inner()
File "C:\Users\XXX\PycharmProjects\ad-assignment\lib\werkzeug\serving.py", line 656, in inner
fd=fd)
File "C:\Users\XXX\PycharmProjects\ad-assignment\lib\werkzeug\serving.py", line 550, in make_server
passthrough_errors, ssl_context, fd=fd)
File "C:\Users\XXX\PycharmProjects\ad-assignment\lib\werkzeug\serving.py", line 464, in __init__
HTTPServer.__init__(self, (host, int(port)), handler)
File "C:\Python27\Lib\SocketServer.py", line 417, in __init__
self.server_bind()
File "C:\Python27\Lib\BaseHTTPServer.py", line 108, in server_bind
SocketServer.TCPServer.server_bind(self)
File "C:\Python27\Lib\SocketServer.py", line 431, in server_bind
self.socket.bind(self.server_address)
File "C:\Users\XXX\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\dist27\socket.py", line 222, in meth
return getattr(self._sock,name)(*args)
File "C:\Users\XXX\AppData\Local\Google\Cloud SDK\google-cloud-sdk\platform\google_appengine\google\appengine\api\remote_socket\_remote_socket.py", line 676, in bind
raise _SystemExceptionFromAppError(e)
error: [Errno 13] Permission denied
INFO 2016-12-16 21:41:51,631 module.py:788] default: "GET /oauth2callback?code=x/xxxxxxxxxxxxxxxxx HTTP/1.1" 500 -
Code (as seen in Google's OAuth2 usage guide):
import flask
app = flask.Flask(__name__)
#app.route('/')
def index():
...
#app.route('/oauth2callback')
def oauth2callback():
...
if __name__ == 'main':
import uuid
app.secret_key = str(uuid.uuid4())
app.debug = False
app.run()
We have a tutorial that walks you through adding Firebase Authentication to your Python app running with Flask. Firebase Authentication is the preferred identity toolkit now. You can of course still use a pure OAuth2 flow, but Firebase Auth also provides multi-provider authentication if that's something you were considering adding to your app anyways. If you just want to dive into the sample's code its here on GitHub.
If you just want to stick with straight OAuth, you might want to look at your Flask code itself. Getting flask to run is pretty easy on App Engine. My guess is that you're calling some code that you don't need to (flask.run()) or you aren't importing your library properly (see appengine_config.py).

Python + Flask web app reports "[Errno 9] Bad file descriptor" with pexpect module

I am developing a web app using Python + Flask. In the simplest sense, a request from the client to a specific URL will trigger the app to login into a remote machine on the server side, perform a series of shell commands, and parse and send the output (formatted in JSON) to the client as part of the response. These commands are fairly simple. To log in to the remote machine, the only method available to me is rlogin, so I used the pexpect module since I couldn't find any standard Python modules for rlogin.
Now the problem is that while I am able to get the correct output from pexpect/rlogin, sending that output (a string) as a response results in an error:
----------------------------------------
Exception happened during processing of request from ('171.71.55.54', 62736)
Traceback (most recent call last):
File "/isan/python/python2.7/SocketServer.py", line 295, in _handle_request_noblock
self.process_request(request, client_address)
File "/isan/python/python2.7/SocketServer.py", line 321, in process_request
self.finish_request(request, client_address)
File "/isan/python/python2.7/SocketServer.py", line 334, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/isan/python/python2.7/SocketServer.py", line 651, in __init__
self.finish()
File "/isan/python/python2.7/SocketServer.py", line 710, in finish
self.wfile.close()
File "/isan/python/python2.7/socket.py", line 279, in close
self.flush()
File "/isan/python/python2.7/socket.py", line 303, in flush
self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 9] Bad file descriptor
----------------------------------------
I've stripped the code down to the bare minimum required to reproduce the error. An HTTP request to this app results in the "Bad file descriptor" error. Sorry for the varying indentation, I was using two different editors to modify the code!
import os
import subprocess
import pexpect
from flask import Flask
app = Flask(__name__)
class rlogin:
def __init__(self, host, prompt):
self.child = pexpect.spawn("rlogin " + host)
self.prompt = prompt
self.child.expect_exact(self.prompt)
def command(self, command):
self.child.sendline(command)
self.child.expect_exact(self.prompt)
response = self.child.before
return response
def close(self):
self.child.close()
#app.route('/')
def index():
rl = rlogin("myserver", "root#myserver:~# ")
output = rl.command("pwd")
rl.close()
# The output of the next line is just as I expect:
print output
# This is probably where it fails:
return output
if __name__ == '__main__':
app.run(host='0.0.0.0', debug=True)
Removing the calls to rlogin(), rl.command() and rl.close(), and returning a simple string like "A" resolves the error. I've been stuck on this issue for a while now, and would hugely appreciate any help. Thanks!
You will have to make sure that the return type is str, unicode, response class or WSGI function. It looks like your output doesn't belong to any of the accepted Flask route return types.
#app.route('/')
def index():
rl = rlogin("myserver", "...")
output = rl.command("pwd")
rl.close()
print type(output)
# Convert output into something that flask can understand
value = str(output)
resp = make_response(value)
resp.headers['Content-Type'] = 'text/plain'
return resp
You can read more about this at http://flask.pocoo.org/docs/0.10/api/#flask.Flask.make_response

Django LiveServerTestCase with phantomjs intermittent hangs / timeouts

I'm using Django (1.5.5), selenium (2.41.0), splinter (0.6.0) and phantomjs (1.9.7) for running live tests.
While the tests mostly work, every now and then (very often on CircleCI, less often in a local VM) they hang until either there's a timeout on CircleCI or I kill the runner manually (Ctrl-C ie. KeyboardInterrupt works).
This is how my base test class looks:
class SplinterTestCase(LiveServerTestCase):
#classmethod
def setUpClass(cls):
super(SplinterTestCase, cls).setUpClass()
# start phantom just once per class, to speed up tests
cls.phantom = splinter.Browser('phantomjs', load_images=False)
#classmethod
def tearDownClass(cls):
cls.phantom.quit()
super(SplinterTestCase, cls).tearDownClass()
def login(self, *args, **kwargs):
# perform a login using Django builtin "client", steal the session
# cookie and inject it to phantomjs, avoiding the need to do the
# login dance for each test
from django.conf import settings
cn = settings.SESSION_COOKIE_NAME
self.django_client.login(*args, **kwargs)
if cn in self.django_client.cookies:
self.client.driver.add_cookie({
'name': cn,
'value': self.django_client.cookies[cn].value,
'path': '/',
'domain': 'localhost'
})
def setUp(self):
# use phantom as the test client instead of Django's
super(SplinterTestCase, self).setUp()
self.django_client = self.client
self.client = self.phantom
def tearDown(self):
# this seems to help somewhat (decreases the number of timeouts), but
# doesn't solve it completely
self.client.visit('about:config')
super(SplinterTestCase, self).tearDown()
After Ctrl-C, this is the stacktrace I get:
Traceback (most recent call last):
File "/usr/lib/python2.7/wsgiref/handlers.py", line 86, in run
self.finish_response()
File "/usr/lib/python2.7/wsgiref/handlers.py", line 127, in finish_response
self.write(data)
File "/usr/lib/python2.7/wsgiref/handlers.py", line 215, in write
self._write(data)
File "/usr/lib/python2.7/socket.py", line 324, in write
self.flush()
File "/usr/lib/python2.7/socket.py", line 303, in flush
self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 104] Connection reset by peer
Traceback (most recent call last):
File "/home/ubuntu/memo-angel/venv/local/lib/python2.7/site-packages/django/test/testcases.py", line 998, in _handle_request_noblock
self.process_request(request, client_address)
File "/usr/lib/python2.7/SocketServer.py", line 310, in process_request
self.finish_request(request, client_address)
File "/usr/lib/python2.7/SocketServer.py", line 323, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/home/ubuntu/memo-angel/venv/local/lib/python2.7/site-packages/django/core/servers/basehttp.py", line 150, in __init__
super(WSGIRequestHandler, self).__init__(*args, **kwargs)
File "/usr/lib/python2.7/SocketServer.py", line 640, in __init__
self.finish()
File "/usr/lib/python2.7/SocketServer.py", line 693, in finish
self.wfile.flush()
File "/usr/lib/python2.7/socket.py", line 303, in flush
self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 32] Broken pipe
A similar problem might've been discussed in Django with splinter and phantomjs is painfully slow as the original poster also mentioned "it just freezes until I am out of patience to wait for it to finish". The answer there mentioned to try to put phantomjs start/stop in class setup/teardown, which I did here, but it doesn't solve the problem.
Has anyone experienced a similar problem, and if you have, what are your workarounds?
To identify the issue and make your tests fail faster, you may want to configure a socket timeout inside your setUpClass / setUp:
import socket
...
socket.setdefaulttimeout(10)

Bottle causing a python program to crash? Uses simple implementation of threads, queues, and forking

I've tried to simplify this as much as possible but I'm still getting an error. I have a simple http server (bottle) that upon receiving a post request executes a function which is supposed to quickly fork itself. The parent process simply returns a job ID and closes while the child process continues to process same data (which is a list of URLs). I've removed all the input and output functions and hard coded the data but my program is still crashing. The funny part is when I alter the program to run directly at the command line rather then start an http server and wait for bottle to execute it everything works fine!
#!/usr/bin/python
#This is a comment
import sys, time, bottle, os
from threading import Thread
from Queue import Queue
from bottle import route, run, request, abort
num_fetch_threads = 2
url_queue = Queue()
def fetchURLContent(i, q):
while True:
#print '%s: Looking for URLs in queue' % i
url = q.get()
#print 'URL found: %s' % url[0]
q.task_done()
time.sleep(1)
#route('/', method='POST') # or #route('/login', method='POST')
def main():
urls = ['http://www.yahoo.com', 'http://www.google.com']
newpid = os.fork()
if newpid == 0:
for i in range(num_fetch_threads):
worker = Thread(target=fetchURLContent, args=(i, url_queue))
worker.setDaemon(True)
worker.start()
print 'Queuing: ', url
for url in urls:
url_queue.put(url)
time.sleep(2)
print 'main thread waiting...'
url_queue.join()
print 'Done'
else:
print "Your job id is 5"
return
def webServer():
run(host='33.33.33.10', port=8080)
if __name__ == "__main__":
print 'Listening on 8080...'
webServer()
The error message I get is as follows:
Listening on 8080...
Bottle v0.11.3 server starting up (using WSGIRefServer())...
Listening on http://33.33.33.10:8080/
Hit Ctrl-C to quit.
33.33.33.1 - - [19/Oct/2012 21:21:24] "POST / HTTP/1.1" 200 0
Traceback (most recent call last):
File "/usr/lib/python2.7/wsgiref/handlers.py", line 86, in run
self.finish_response()
File "/usr/lib/python2.7/wsgiref/handlers.py", line 128, in finish_response
self.finish_content()
File "/usr/lib/python2.7/wsgiref/handlers.py", line 246, in finish_content
self.send_headers()
9 url_queue = Queue()
File "/usr/lib/python2.7/wsgiref/handlers.py", line 268, in send_headers
self.send_preamble()
File "/usr/lib/python2.7/wsgiref/handlers.py", line 189, in send_preamble
self._write('HTTP/%s %s\r\n' % (self.http_version,self.status))
File "/usr/lib/python2.7/wsgiref/handlers.py", line 389, in _write
self.stdout.write(data)
File "/usr/lib/python2.7/socket.py", line 324, in write
self.flush()
File "/usr/lib/python2.7/socket.py", line 303, in flush
self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 32] Broken pipe
----------------------------------------
Exception happened during processing of request from ('33.33.33.1', 57615)
Traceback (most recent call last):
File "/usr/lib/python2.7/SocketServer.py", line 284, in _handle_request_noblock
self.process_request(request, client_address)
File "/usr/lib/python2.7/SocketServer.py", line 310, in process_request
self.finish_request(request, client_address)
File "/usr/lib/python2.7/SocketServer.py", line 323, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib/python2.7/SocketServer.py", line 640, in __init__
self.finish()
File "/usr/lib/python2.7/SocketServer.py", line 693, in finish
self.wfile.flush()
File "/usr/lib/python2.7/socket.py", line 303, in flush
self._sock.sendall(view[write_offset:write_offset+buffer_size])
error: [Errno 32] Broken pipe
----------------------------------------
Any ideas?
Your main() function terminates immediately without returning anything. Bottle writes an empty HTTP response to the socket and the web server closes the connection.
Your forked off process stays a bit longer in main(), but then terminates too and causes Bottle to write another empty response to the already closed socket. Thats the error you get (broken pipe).
Forking at that point cannot work. HTTP does not allow more than one response per request. You can either block until all work is done and then send a response, or send the response immediately and do the work in a differed thread.

python xmlrpc timeout error

I am using xmlrpc to contact a local server. On the client side, Sometimes the following socket timeout error and happens and its not a consistent error.
Why is it happening? What could be the reason for socket timeout?
<class 'socket.timeout'>: timed out
args = ('timed out',)
errno = None
filename = None
message = 'timed out'
strerror = None
Traceback on the server side is as follows
Exception happened during processing of request from ('127.0.0.1', 34855)
Traceback (most recent call last):
File "/usr/lib/python2.4/SocketServer.py", line 222, in handle_request
self.process_request(request, client_address)
File "/usr/lib/python2.4/SocketServer.py", line 241, in process_request
self.finish_request(request, client_address)
File "/usr/lib/python2.4/SocketServer.py", line 254, in finish_request
self.RequestHandlerClass(request, client_address, self)
File "/usr/lib/python2.4/SocketServer.py", line 521, in __init__
self.handle()
File "/usr/lib/python2.4/BaseHTTPServer.py", line 314, in handle
self.handle_one_request()
File "/usr/lib/python2.4/BaseHTTPServer.py", line 308, in handle_one_request
method()
File "/usr/lib/python2.4/SimpleXMLRPCServer.py", line 441, in do_POST
self.send_response(200)
File "/usr/lib/python2.4/BaseHTTPServer.py", line 367, in send_response
self.send_header('Server', self.version_string())
File "/usr/lib/python2.4/BaseHTTPServer.py", line 373, in send_header
self.wfile.write("%s: %s\r\n" % (keyword, value))
File "/usr/lib/python2.4/socket.py", line 256, in write
self.flush()
File "/usr/lib/python2.4/socket.py", line 243, in flush
self._sock.sendall(buffer)
error: (32, 'Broken pipe')
I killed the server and restarted it. Its working fine now.
What could be the reason?
My machine's RAM went full yesterday night by a process and came back to normal today morning.
Will this error be because of some swapping of processes?
Looks like the client socket it timing out waiting for the server to respond. Is it possible that your server might take a lot time to respond some times? Also, if the server is causing the machine to go into swap, that would slow it down making a timeout possible.
If I remember right, socket timeout is not set in xmlrpc in python. Are you doing socket.setdefaulttimeout somewhere in your code?
If it is expected that your server will take time once in a while, then you could set a higher timeout value using above.
HTH

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