nginx + gunicorn + pyramid: Get actual domain name from headers - nginx

Question

I just setup nginx + gunicorn to serve up a Pyramid web application. My application relies on getting the subdomain, which is different for every client. I didn't know this before, but when going through gunicorn, it seems that the only thing I can get from domain is what i have in my INI file used to configure Gunicorn - localhost.
I'm wondering if there is a way to get the actual, full domain name where the request originated? It can't be anything hard coded since the subdomains could be different for each request. Does anyone have any ideas how to make this happen?
UPDATE
I made the change requested by Fuero, changing the value I had for
proxy_set_header Host $http_host;
to
proxy_set_header Host $host;
Unfortunately, that didn't do it. I'm still seeing 127.0.0.1:6500 in the environment as the remote address, host, etc. The only thing that shows me the actual client request domain is the referrer. I'm including my config file below hoping something stills stand out.
user www-data;
worker_processes 4;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
# multi_accept on;
}
http {
##
# Basic Settings
##
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
# server_tokens off;
# server_names_hash_bucket_size 64;
# server_name_in_redirect off;
include /etc/nginx/mime.types;
default_type application/octet-stream;
##
# Logging Settings
##
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
##
# Gzip Settings
##
# sendfile on;
gzip on;
gzip_http_version 1.1;
gzip_vary on;
gzip_comp_level 6;
gzip_proxied any;
gzip_types text/plain text/html text/css
application/json application/x-javascript
text/xml application/xml application/xml+rss
text/javascript application/javascript text/x-js;
gzip_buffers 16 8k;
gzip_disable "MSIE [1-6]\.(?!.*SV1)";
##
# Virtual Host Configs
##
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
upstream myapp-site {
server 127.0.0.1:6500;
}
server {
access_log /var/www/tmsenv/logs/access.log;
location / {
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
client_max_body_size 10m;
client_body_buffer_size 128k;
proxy_connect_timeout 60s;
proxy_send_timeout 90s;
proxy_read_timeout 90s;
proxy_buffering off;
proxy_temp_file_write_size 64k;
proxy_pass http://myapp-site;
proxy_redirect off;
}
}
}

Answer 1

Since you're using WSGI, you can find the hostname in environ['HTTP_HOST'] See PEP 333 for more details and other information you can retrieve.

Answer 2

Add this to your config:
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $host;
This preserves the server name that was entered in the browser in the Host: header and adds the client's IP address in X-Forwarded-For:.
Access them via environ['HTTP_HOST'] and environ['HTTP_X_FORWARDED_FOR']. WSGI might be smart enough to respect X-Forwarded-For: though when setting REMOTE_IP.

Answer 3

I finally got this working and the fix was something stupid, as typical. While digging for answers I noticed my config didn't have the root or static directory location for which I'm using nginx in the first place. I asked the person who set this up and they pointed out that it was in another config file, which is consumed via the include.
include /etc/nginx/sites-enabled/*;
I went to that file and added the suggested headers and it works.
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $host;