We Keep Coding

Flask - strict_slashes redirects to http instead of https

I have a flask server running on localhost:8080. I have set up nginx as a reverse proxy from my domain to localhost:8080 and have set up SSL. The automatic HTTPS works fine, except when Flask returns a 308 and redirects the client due to the strict_slashes rule. It redirects the user to a http URL instead of a https one, causing the page to not load. How do I make strict_slashes return redirects to a HTTPS url instead of a HTTP one.

Since Flask url_for does not respect http or https while redirecting, always use redirect(url_for('func_name', _external=True)) to respect the root URL and Scheme(http or https) used.
Alternatively, I used this in one of such cases to explicitly redirect to HTTPS
response_body = redirect(url_for('.route_function', _external=True))
response = app.make_response(response_body)
response.location = response.location.replace("http://", "https://")
return response

Flask Server not responding to HTTP POST Request

I built a simple flask server in order to automate python scripts based on an HTTP POST Request coming in from an outside service. This service sends these requests in response to events that we have created based on data conditions. All the flask server needs to do is parse the requests, and take the numerical value stored in the request and use it to run the corresponding python script. At one point, this system was working consistently. Fast forward a few months, the server was no longer working when tried again. No changes were made to the code. According to wireshark, The computer hosting the flask server is receiving the request to the correct port, but the request is now timing out. The host system is failing to respond to the request. Any Idea what is going on here? The firewall has temporarily been turned off.
Alternatively, is there another better package to achieve this goal with?
from flask import Flask, request
import threading
import runpy
app = Flask(__name__)
#app.route('/', methods=['POST'])
def PostHandler():
directory = {}
with open(r"M:\redacted") as f:
for line in f:
(key,val) = line.split()
directory[int(key)] = val
print(directory)
path = r"M:\redacted"
content = request.json
content = content['value']
print(content)
sel_script = int(content)
print(directory[sel_script])
runpy.run_path(path_name=path + directory[sel_script])
return
app.run(host="10.244.xx.xx", port=8080, threaded=True)

flask proxy for ttyd

I am looking for a method to write a simple proxy in flask for ttyd which is an open-source web terminal(https://github.com/tsl0922/ttyd). The most immediate way is to read client request and relay to ttyd server. However, it fails when the websocket is connecting.
My view function is as follows:
#app.route('/')
#app.route('/auth_token.js')
#app.route('/ws')
def ttyd():
if request.path=='/ws':
url = 'ws://192.168.123.172:7681' + request.path
else:
url = 'http://192.168.123.172:7681' + request.path
method = request.method
data = request.data or request.form or None
cookies = request.cookies
headers = request.headers
with closing(
requests.request(method, url, headers=headers, data=data, cookies=cookies)
) as r:
resp_headers = []
for name, value in r.headers.items():
resp_headers.append((name, value))
return Response(r, status=r.status_code, headers=resp_headers)
As you can see, the view function will handle 3 url requests, the first two succeed with status code 200, the third fails with status code 500. The error code in server side is as follows:
requests.exceptions.InvalidSchema: No connection adapters were found for 'ws://192.168.123.172:7681/ws'
I also check the network in two cases(with/without proxy). The picture 'without proxy' means direct type 'http://192.168.123.172:7681', it succeeds. The picture 'with proxy' means access ttyd server with flask proxy, it fails.
Without proxy
With proxy
Since I am new to flask and websocket, I am confused about the result. The sHTTPe flask proxy can handle any other http request(e.g. access google.com) but fails in WebSocket connection.
Thank you for telling me why and how can I fix it?

According to Websockets in Flask there is a flask-sockets project at https://github.com/heroku-python/flask-sockets to serve a websocket-endpoint in flask. To make the backend websocket connection to the server you can't use requests but websocket-client, see How do I format a websocket request?.
When I had this problem I solved it using the autobahn-python project, see https://github.com/arska/stringreplacingwebsocketproxy/
Cheers,
Aarno

503 Reponse when trying to use python request on local website

I'm trying to scrape my own site from my local server. But when I use python requests on it, it gives me a response 503. Other ordinary sites on the web work. Any reason/solution for this?
import requests
url = 'http://127.0.0.1:8080/full_report/a1uE0000002vu2jIAA/'
r = requests.get(url)
print r
prints out
<Response [503]>
After further investigation, I've found a similar problem to mine.
Python requests 503 erros when trying to access localhost:8000
However, I don't think he's solved it yet. I can access the local website via the web browser but can't access using the requests.get function. I'm also using Django to host the server.
python manage.py runserver 8080
When I use:
curl -vvv http://127.0.0.1:8080
* Rebuilt URL to: http://127.0.0.1:8080/
* Trying 10.37.135.39...
* Connected to proxy.kdc.[company-name].com (10.37.135.39) port 8099 (#0)
* Proxy auth using Basic with user '[company-id]'
> GET http://127.0.0.1:8080/ HTTP/1.1
> Host: 127.0.0.1:8080
> Proxy-Authorization: Basic Y2FhNTc2OnJ2YTkxQ29kZQ==
> User-Agent: curl/7.49.0
> Accept: */*
>
< HTTP/1.1 301 Moved Permanently
< Server: BlueCoat-Security-Appliance
< Location:http://10.118.216.201
< Connection: Close
<
<HTML>
<HEAD><TITLE>Redirection</TITLE></HEAD>
<BODY><H1>Redirect</H1></BODY>
* Closing connection 0

I cannot request a local url using python requests because the company's network software won't allow it. This is a dead end and other avenues must be pursued.
EDIT: Working Solution
>>> import requests
>>> session = requests.Session()
>>> session.trust_env = False
>>> r = session.get("http://127.0.0.1:8080")
>>> r
<Response [200]>

Maybe you should disable your proxies in your requests.
import requests
proxies = {
"http": None,
"https": None,
}
requests.get("http://127.0.0.1:8080/myfunction", proxies=proxies)
ref:
https://stackoverflow.com/a/35470245/8011839
https://2.python-requests.org//en/master/user/advanced/#proxies

HTTP Error 503 means:
The Web server (running the Web site) is currently unable to handle the HTTP request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition which will be alleviated after some delay. Some servers in this state may also simply refuse the socket connection, in which case a different error may be generated because the socket creation timed out.
You may do following things:
Check you are able to open URL in the browser
If URL is opening, then check the domain in your code, it might be incorrect.
If in browser also it is not opening, your site may be overloaded or server resources are full to perform request

The most common cause of a 503 error is that a proxy host of some form is unable to communicate with the back end. For example, if you have Varnish trying to handle a request but Apache is down.
In your case, you have Django running on port 8080. (That's what the 8080 means). When you try to get content from 127.0.0.1, though, you're going to the default HTTP port (80). This means that your default server (Apache maybe? NginX?) is trying to find a host to serve 127.0.0.1 and can't find one.
You have two choices. Either you can update your server's configuration, or you can include the port in the URL.
url = 'http://127.0.0.1:8080/full_report/a1uE0000002vu2jIAA/'

Authenticate Windows Security with Request library

How can I authenticate in his Windows Security pop-up?
http://imgur.com/1FSkbUF
using requests and python?
from requests import session
with session() as c:
response = c.get('url', auth=('username', 'pass'),)
print(response.headers)
print(response.text)
but it does not work, it still prints error message source code

Ok, started working. It was just a internal server error. After several tries I had to be blocked for a while.