Nginx/Pyramid custom SSL port - nginx

Question

As a prefix, I have been using the following stack for some time with great success:
NGINX - web proxy
SSL - configured in nginx
Pyramid web application, served by gunicorn
The above combo works great, here is a working configuration.
server {
# listen on port 80
listen 80;
server_name portalapi.example.com;
# Forward all traffic to SSL
return 301 https://www.portalapi.example.com$request_uri;
}
server {
# listen on port 80
listen 80;
server_name www.portalapi.example.com;
# Forward all traffic to SSL
return 301 https://www.portalapi.example.com$request_uri;
}
#ssl server
server {
listen 443 ssl;
ssl on;
ssl_certificate /usr/local/etc/letsencrypt/live/portalapi.example.com/fullchain.pem;
ssl_certificate_key /usr/local/etc/letsencrypt/live/portalapi.example.com/privkey.pem;
server_name www.portalapi.example.com;
client_max_body_size 10M;
client_body_buffer_size 128k;
location ~ /.well-known/acme-challenge/ {
root /usr/local/www/nginx/portalapi;
allow all;
}
location / {
proxy_set_header Host $host;
proxy_pass http://10.1.1.16:8005;
#proxy_intercept_errors on;
allow all;
}
error_page 404 500 502 503 504 /index.html;
location = / {
root /home/luke/ecom2/dist;
}
}
Now, this is how I serve my public facing apps, it works very well. For all my internal applications, I used to simply direct users to an internal domain example: http://subdomain.company.domain , again this worked well for a long time.
Now in the wake of KRACK attack although we have some very thorough firewall rules to prevent a lot of attacks, I want to force all internal traffic through SSL, and I don't want to use a self signed certificate, I want to use lets encrypt so I can auto-renew certificates which makes administration much easier (and cheaper).
In order to use lets encrypt, I need to have a public facing DNS and server to perform the ACME challenge (for auto renewing). Now again this was a very easy thing to setup in nginx, and the below config works perfectly for serving static content:
What it does is if a user from the internet accesses intranet.example.com it simply shows a forbidden message. However, if a local user tries, they get forwarded to intranet.example.com:8002 and the port 8002 is only available locally, so there is no way external users can access a webpage on this site
geo $local_user {
192.168.155.0/24 0;
172.16.10.0/28 1;
172.16.155.0/24 1;
}
server {
listen 80;
server_name intranet.example.com;
client_max_body_size 4M;
client_body_buffer_size 128k;
# Space for lets encrypt to perform challenges
location ~ /\.well-known/ {
root /usr/local/www/nginx/intranet;
}
if ($local_user) {
# If user is local, redirect them to SSL proxy only available locally
return 301 https://intranet.example.com:8002$request_uri;
}
# Default block all non local users see
location / {
root /home/luke/forbidden_html;
index index.html;
}
# This server block is only available to local users inside geo $local_user
# this block listens on an internal port only, so it is never availble to
# external networks
server {
listen 8002 default ssl; # listen on a port only accessible locally
server_name intranet.example.com;
ssl_certificate /usr/local/etc/letsencrypt/live/intranet.example.com/fullchain.pem;
ssl_certificate_key /usr/local/etc/letsencrypt/live/intranet.example.com/privkey.pem;
client_max_body_size 4M;
client_body_buffer_size 128k;
location / {
allow 192.168.155.0/24;
allow 172.16.10.0/28; # also add in allow/deny rules in this block (extra security)
allow 172.16.155.0/24;
root /home/luke/ecom2/dist;
index index.html;
deny all;
}
}
Now, here comes the pyramid/nginx marrying problem, if I use the same above configuration, but have the below settings for my server on 8002:
server {
listen 8002 default ssl; # listen on a port only accessible locally
server_name intranet.example.com;
ssl_certificate /usr/local/etc/letsencrypt/live/intranet.example.com/fullchain.pem;
ssl_certificate_key /usr/local/etc/letsencrypt/live/intranet.example.com/privkey.pem;
client_max_body_size 4M;
client_body_buffer_size 128k;
location / {
allow 192.168.155.0/24;
allow 172.16.10.0/28; # also add in allow/deny rules in this block (extra security)
allow 172.16.155.0/24;
# Forward all requests to python application server
proxy_set_header Host $host;
proxy_pass http://10.1.1.16:6543;
proxy_intercept_errors on;
deny all;
}
}
I run into all sorts of problems, first off inside pyramid I was using the following code in my views/templates
request.route_url # get route url for desired function
Now using request.route_url with the above settings should cause https://intranet.example.com:8002/login to route tohttps://intranet.example.com:8002/welcome but in reality, this setup would forward a user to: http://intranet.example.com/welcome Again this is not correct.
And if I use route_url with the NGINX proxy setting:
proxy_set_header Host $http_host;
I get the error: NGINX to return a 400 error:
400: The plain HTTP request was sent to HTTPS port
And a request to: https://intranet.example.com:8002/ gets reverted to: http://intranet.example.com/login (omitting port and https)
Then I used the same nginx settings (header $htto), but thought I would change to using:
request.route_path
My theory was this should force everything to stay on the same url prefix, and just forward a user from https://intranet.example.com:8002/login to https://intranet.example.com:8002/welcome but in reality, this setup performed the same way as using route_url.
proxy_set_header Host $http_host;
I then get an error when navigating to https://intranet.example.com:8002
400: The plain HTTP request was sent to HTTPS port
And a request to: https://intranet.example.com:8002/ gets reverted to: http://intranet.example.com/login (omitting port and https)
Can anyone assist with the correct setup in order for me to serve my application on https://intranet.example.com:8002
EDIT:
Have also tried:
location / {
allow 192.168.155.0/24;
allow 172.16.10.0/28; # also add in allow/deny rules in this block (extra security)
allow 172.16.155.0/24;
# Forward all requests to python application server
proxy_set_header Host $host:$server_port;
proxy_pass http://10.1.1.16:8002;
proxy_intercept_errors on;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
# root /home/luke/ecom2/dist;
# index index.html;
deny all;
}
Which gives the same result.

Answer 1

I’ve checked a similar configuration and your last example seems correct,
at least for a simplistic gunicorn/pyramid app combination.
Seems something is missing in your puzzle )
Here’s my code (I’m new to Pyramid so something might be done better)
helloworld.py
from pyramid.config import Configurator
from pyramid.renderers import render_to_response
def main(request):
return render_to_response('templates:test.pt', {}, request=request)
with Configurator() as config:
config.add_route('main', '/')
config.add_view(main, route_name='main')
config.include('pyramid_chameleon')
app = config.make_wsgi_app()
templates/test.pt
<html>
<body>
Route url: ${request.route_url('main')}
</body>
</html>
My nginx config
server {
listen 80;
server_name pyramid.lan;
location / {
return 301 https://$server_name:8002$request_uri;
}
}
server {
listen 8002;
server_name pyramid.lan;
ssl on;
ssl_certificate /usr/local/etc/nginx/cert/server.crt;
ssl_certificate_key /usr/local/etc/nginx/cert/server.key;
location / {
proxy_set_header Host $host:$server_port;
proxy_pass http://127.0.0.1:5678;
proxy_set_header X-Forwarded-Proto $scheme;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
}
}
This is how I run gunicorn:
gunicorn -w 1 -b 127.0.0.1:5678 helloworld:app
And yes, it works:
$ curl --insecure https://pyramid.lan:8002/
<html>
<body>
Route url: https://pyramid.lan:8002/
</body>
</html>
$ curl -D - http://pyramid.lan
HTTP/1.1 301 Moved Permanently
Server: nginx/1.12.2
Date: Thu, 02 Nov 2017 20:41:50 GMT
Content-Type: text/html
Content-Length: 185
Connection: keep-alive
Location: https://pyramid.lan:8002/
Lets figure out what might go wrong in your case
http 400 usually pops up when you go over httP instead of httpS to a server awaiting httpS requests. If there’s no typo in the post and it indeed occurs when you navigate to https://intranet.example.com:8002 it would be nice to see a curl request showing this and a tcpdump showing what’s happening. Actually you can easily reproduce it by simply typing http://intranet.example.com:8002
another idea is that you’re doing a redirect from your app and the link gets broken when the redirect occurs. I better description on how the user may navigate from https://intranet.example.com:8002/login to .../welcome would be helpful
one more idea is that your app is not that simple and you use some middlewares / customization that makes the default logic work differently and your X-Forwarded-Proto header gets ignored - in this case the behavior would be just as you described

Answer 2

The issue here is, obviously, the missing port within the Location directives that your backend produces.
Now, why is the port missing? Most certainly, because of the following code:
proxy_set_header Host $host;
Note that $host itself does not contain $server_port, unlike $http_host, so, your backend would have no way of knowing which port you meant if you just use $host all by itself.
Note that proxy_redirect default of default expects Location to correspond with the value from proxy_pass in order to do its magic (according to documentation), so, your explicit header setting likely interferes with such logic.
As such, from the nginx point of view, I see multiple possible independent solutions:
remove proxy_set_header Host, and let proxy_redirect do its magic;
set proxy_set_header Host appropriately, to include the port number, e.g., using $host:$server_port or $http_host as you see fit (if that doesn't work, then perhaps the deficiency is actually within your upstream app itself, but fear not -- read below);
provide a custom proxy_redirect setting, e.g., proxy_redirect https://pyramid.lan/ / (equivalent to proxy_redirect https://pyramid.lan/ https://pyramid.lan:8002/), which will ensure that all the Location responses will have the proper port; the only way this wouldn't work is if your upstream does non-HTTP redirects with the missing port.