Connection error with Tornado Websockets + Django + Azure + Apache - python

I am running my application with Windows Azure on a Virtual Machine with ubuntu 14.04 lts. I am running my Django application through WSGI on Apache.
Previously i ran django locally with the command "python manage.py runserver", and every thing worked fine when my website connected to my sockets.py file from website.html.
I am running Django through Apache on public ip port 80
I am running the sockets.py separately in a terminal through Putty
I am reading the error through the Google Chrome console
Suddenly this error occurs: Failed to execute 'send' on 'WebSocket': Still in CONNECTING state. whenever i try to connect to the socket.
After a while my page response with: failed: Error in connection establishment: net::ERR_CONNECTION_TIMED_OUT
website.html js:
ws = new WebSocket("ws://10.77.22.74:1339/ws");
function load_all() {
target = "load_all"
ws.send(target)
}
ws.onmessage = function(evt) {
console.log(evt.data)
}
The ip is my internal ip on my virtual machine.
sockets.py:
import tornado.httpserver
import tornado.websocket
import tornado.ioloop
import tornado.web
class WSHandler(tornado.websocket.WebSocketHandler):
def check_origin(self, origin):
return True
def open(self):
print 'new connection'
def on_message(self, message):
self.write_message(message)
def on_close(self):
print 'connection closed'
application = tornado.web.Application([
(r'/ws', WSHandler),
])
if __name__ == "__main__":
http_server = tornado.httpserver.HTTPServer(application)
http_server.listen(1339)
tornado.ioloop.IOLoop.instance().start()
I have tried to change the http_server.listen(1339) to http_server.listen(1339, adress='10.77.22.74') (sockets.py)
I have tried using my public ip and opening a port through tcp (endpoints) and adjusting the scripts after that (sockets.py & website.html)
I have tried running with the localhost & 127.0.0.1 (sockets.py & website.html)
I have tried with ws & wss
I still get the error for some reason, do i need to give Apache (www-data) some permissions to connect to the sockets.py?
Which IP should i use, both on socket.py and website.htm?
Solved
Turn out Tornado is listening to all IP:s if you not specify the adress in the socket server. I opened a port on the public IP and used that IP for my javascript socket connection.

Related

Connection refused while querying a web server which runs on an ephemeral port

I want to run a web server on an ephemeral port and somehow keep the knowledge of its number. I decided to do it in such a way:
from flask import Flask
import socket
app = Flask(__name__)
def find_free_port():
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(("0.0.0.0", 0))
port = sock.getsockname()[1]
sock.close()
return port
#app.route("/")
def home():
return "Hello, World!"
if __name__ == "__main__":
app.run(host="0.0.0.0", port=find_free_port())
On my personal computer I can query both localhost and 0.0.0.0 but there is a machine where it does not work, I receive
curl: (7) Failed connect to localhost:<port_number>; Connection refused
What might be the cause? The problem disappears when I use localhost as the interface instead of binding to all of them
If you try to use the real IP address lets say 192.168.1.104 on the other machine, it will work.
This is because when you use 0.0.0.0 on the other machine, you will be requesting from the same machine yet the port is not open.
so change the request to http://ip_address:port_number

Flask Socket on Ubuntu AWS is not receive message/data, but in the local machine it works fine, no Connect refused

Situation:
I deploy my flask server in the AWS EC2 ubuntu and running. And react.js running on my local machine try to test is remote server setup correctly and works, contains Restful API and WebSocket.
Question:
Everything works fine on the local machine which python and react both running on the local machine. When l make flask running on the AWS, the Restful API works fine, but WebSocket is not working, there is no connect refused error, switch protocol is 101 and in the inspector network section is 200 status. Just remote server cannot receiving data. I am not sure what was happended at this time and how to fix that, anyone has the same experience?
this one is my client
const endPoint = "http://3.237.172.105:5000/friends";
const socket = io.connect(endPoint);
const addFriends=(friend)=>{
socket.emit("Addedfriend",{username:name , friendName:friendName});
}
this one is my flask start file: call python3 app.py to run
from logging import debug
from flask import Flask
from flask_socketio import SocketIO
from flask_cors import CORS
from Controller.logReg import logReg
from Controller.profile import profile
from Controller.ticket import ticket
from Controller.personal import personal
import logging
#log = logging.getLogger('werkzeug')
#log.setLevel(logging.ERROR)
app = Flask(__name__)
socketio = SocketIO(app, cors_allowed_origins="*")
app.register_blueprint(logReg)
app.register_blueprint(profile)
app.register_blueprint(ticket)
app.register_blueprint(personal)
print("socket started ... ...")
CORS(app)
if __name__ == '__main__':
print("socket opened")
socketio.run(app, host='0.0.0.0', port=5000)
this is my socket file: print data is not print anything and I am not sure why
#socketio.on('Addedfriend', namespace='/friends')
def add_friend(data, t):
print("this is from addFriend" + str(data))
# print("friend SID: "+str(request.sid))
user = data['username']
friend = data['friendName']
user_friends = FriendsDB.find_one({"username": user})['friends']
if friend in user_friends:
emit("Addedfriend", {"result": "already added", "friendPhoto":"", "friendStatus": False})
return
if FriendsDB.find_one({"username": friend}) is None:
emit("Addedfriend", {"result": "Not Exist", "friendPhoto": "", "friendStatus": False})
return
this is the network screenshot
this is AWS IP address
this is AWS inbound rule

python websocket failure when run in openshift

I have a autobahn twisted websocket running in python which is working in a dev vm correctly but I have been unable to get working when the server is running in openshift.
Here is the shortened code which works for me in a vm.
from autobahn.twisted.websocket import WebSocketServerProtocol, WebSocketServerFactory, listenWS
from autobahn.twisted.resource import WebSocketResource
class MyServerProtocol(WebSocketServerProtocol):
def onConnect(self, request):
stuff...
def onOpen(self):
stuff...
def onMessage(self,payload):
stuff...
factory = WebSocketServerFactory(u"ws://0.0.0.0:8080")
factory.protocol = MyServerProtocol
resource = WebSocketResource(factory)
root = File(".")
root.putChild(b"ws", resource)
site = Site(root)
reactor.listenTCP(8080, site)
reactor.run()
The connection part of the client is as follows:
var wsuri;
var hostname = window.document.location.hostname;
wsuri = "ws://" + hostname + ":8080/ws";
if ("WebSocket" in window) {
sock = new WebSocket(wsuri);
} else if ("MozWebSocket" in window) {
sock = new MozWebSocket(wsuri);
} else {
log("Browser does not support WebSocket!");
window.location = "http://autobahn.ws/unsupportedbrowser";
}
The openshift configuration is as follows:
1 pod running with app.py listening on port 8080
tls not enabled
I have a non-tls route 8080 > 8080.
Firefox gives the following message in the console:
Firefox can’t establish a connection to the server at ws://openshiftprovidedurl.net:8080/ws.
when I use wscat to connect to the websocket.
wscat -c ws://openshiftprovidedurl.net/ws
I get the following error:
error: Error: unexpected server response (400)
and the application log in openshift shows the following:
2018-04-03 01:14:24+0000 [-] failing WebSocket opening handshake ('missing port in HTTP Host header 'openshiftprovidedurl.net' and server runs on non-standard port 8080 (wss = False)')
2018-04-03 01:14:24+0000 [-] dropping connection to peer tcp4:173.21.2.1:38940 with abort=False: missing port in HTTP Host header 'openshiftprovidedurl.net' and server runs on non-standard port 8080 (wss = False)
2018-04-03 01:14:24+0000 [-] WebSocket connection closed: connection was closed uncleanly (missing port in HTTP Host header 'openshiftprovidedurl.net' and server runs on non-standard port 8080 (wss = False))
Any assistance would be appreciated!
Graham Dumpleton hit the nail on the head, I modified the code from
factory = WebSocketServerFactory(u"ws://0.0.0.0:8080")
to
factory = WebSocketServerFactory(u"ws://0.0.0.0:8080", externalPort=80)
and it corrected the issue. I had to modify my index to point to the correct websocket but I am now able to connect.
Thanks!
Based on the source code of autobahn-python, you can get that message only in 2 cases.
Here is the implementation:
if not ((self.factory.isSecure and self.factory.externalPort == 443) or (not self.factory.isSecure and self.factory.externalPort == 80)):
return self.failHandshake("missing port in HTTP Host header '%s' and server runs on non-standard port %d (wss = %s)" % (str(self.http_request_host), self.factory.externalPort, self.factory.isSecure))
Because I think you are using Deployment + Service (and maybe Ingress on top of them) for your server, you can bind your server to port 80 instead of 8080 and set that port in Service and in Ingress, if you are using them.

Cannot access Flask with apache

I have a linux server which I am running my flask app on it like this:
flask run --host=0.0.0.0
Inside the server I can access it like this:
curl http://0.0.0.0:5000/photo (and I am getting a valid response)
However, when I am trying to access it outside the server:
http://my_ip:5000/photo - the connection is refused.
The same ip, will return an image saved on public_html with apache2 configured
http://my_ip/public_html/apple-touch-icon-144x144-precomposed.png
I use this simple snippet to get the ip-address from the interface
import socket
def get_ip_address():
""" get ip-address of interface being used """
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(("8.8.8.8", 80))
return s.getsockname()[0]
IP = get_ip_address()
And in main:
if __name__ == '__main__':
app.run(host=IP, port=PORT, debug=False)
And running:
./app.py
* Running on http://10.2.0.41:1443/ (Press CTRL+C to quit)
I have a suspicion you have a firewall on your Linux machine that is blocking port 5000.
Solution 1:
Open the relevant port on your firewall.
Solution 2:
I would suggest you to install nginx as a web proxy and configure it so that http://my_ip/photo would forward traffic to and from http://127.0.0.1:5000/photo:
server {
listen 80;
location /photo {
proxy_pass http://127.0.0.1:5000/photo;
}
}

one strange behavior of xmlrpc

Here is the code:
server part and called from machine 10.42.0.1:
from xmlrpc.server import SimpleXMLRPCServer
from xmlrpc.server import SimpleXMLRPCRequestHandler
class RequestHandler(SimpleXMLRPCRequestHandler):
rpc_paths = ()
server = SimpleXMLRPCServer(('10.42.0.1', 8000),
requestHandler=RequestHandler)
server.register_function(adder, 'add')
print('initialize finish')
server.serve_forever()
client part, and call from machine 10.42.0.2:
import xmlrpc.client
s = xmlrpc.client.ServerProxy('http://10.42.0.1:8000')
print(s.add(2,3))
However, I've got the error message from machine 10.42.0.2:
ConnectionRefusedError: [Errno 111]. And telnet 10.42.0.1 8000 also failed.
Then, I change this sentence:
server = SimpleXMLRPCServer(('10.42.0.1', 8000),
requestHandler=RequestHandler)
to:
server = SimpleXMLRPCServer(('', 8000),
requestHandler=RequestHandler)
And restart xmlrpc server, the xmlrpc client works this time. Then I change this sentence to:
server = SimpleXMLRPCServer(('10.42.0.1', 8001),
requestHandler=RequestHandler)
And open a new xmlrpc server, and change the client code to:
import xmlrpc.client
s = xmlrpc.client.ServerProxy('http://10.42.0.1:8001')
print(s.add(2,3))
And start a new xmlrpc client, the client now also works.
Anyone help me explain this strange phenomenon?
A bit like arp table not built.

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