python - 'Invalid input syntax for type inet' db error in Django app with postgres and Gunicorn+Nginx as reverse proxy

Question

Can you help me decipher this rather esoteric error? Everything's fine when I fire up the application, but crashes the moment I try to login.

DatabaseError at /login/

invalid input syntax for type inet: "" LINE 1: ...00101 Firefox/41.0', '2015-12-12 09:39:55.590036+00:00', '')

Exception Location: /home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.py in execute, line 54

I know for a fact that the inet data type accepts IPv4 and IPv6 hosts and networks (but not domain names).

The traceback is as follows:

Traceback:
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/core/handlers/base.py" in get_response
  187.                 response = middleware_method(request, response)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/user_sessions/middleware.py" in process_response
  46.                     request.session.save()
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/user_sessions/backends/db.py" in save
  86.                     obj.save(force_insert=must_create, using=using)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/models/base.py" in save
  546.                        force_update=force_update, update_fields=update_fields)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/models/base.py" in save_base
  650.                 result = manager._insert([self], fields=fields, return_id=update_pk, using=using, raw=raw)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/models/manager.py" in _insert
  215.         return insert_query(self.model, objs, fields, **kwargs)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/models/query.py" in insert_query
  1661.     return query.get_compiler(using=using).execute_sql(return_id)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py" in execute_sql
  937.             cursor.execute(sql, params)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/backends/util.py" in execute
  41.             return self.cursor.execute(sql, params)
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.py" in execute
  58.             six.reraise(utils.DatabaseError, utils.DatabaseError(*tuple(e.args)), sys.exc_info()[2])
File "/home/mhb11/.virtualenvs/redditpk/local/lib/python2.7/site-packages/django/db/backends/postgresql_psycopg2/base.py" in execute
  54.             return self.cursor.execute(query, args)

Exception Type: DatabaseError at /login/
Exception Value: invalid input syntax for type inet: ""
LINE 1: ...00101 Firefox/41.0', '2015-12-12 09:39:55.590036+00:00', '')

The /login/ url in urls.py is url(r'^login/$', 'django.contrib.auth.views.login', {'template_name': 'login.html'}, name="login"),

The environment is:

Django 1.5.1 with a postgresql backend and resides on a Ubuntu 14.04 machine. Especially note that this error started coming after I set up nginx as a reverse proxy behind gunicorn (using port 80 for this set up). Things worked perfectly when I used solely gunicorn (and waitress, another pure python web server) on port 8080.

/etc/nginx/sites-available/myproject:

server {
    listen 80;
    server_name example.cloudapp.net;

    location = /favicon.ico { access_log off; log_not_found off; }
    location /static/ {
        root /home/mhb11/folder/myproject;
    }

    location / {
        include proxy_params;
        proxy_pass http://unix:/home/mhb11/folder/myproject/myproject.sock;
    }
   error_page 500 502 503 504 /500.html;
   location = /500.html {
        root /home/mhb11/folder/myproject/templates/;
   }
}

/etc/nginx/proxy_params:

proxy_set_header Host $http_host;
proxy_set_header User-Agent $http_user_agent;
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;

/etc/nginx/nginx.conf:

user www-data;
worker_processes 4;
pid /run/nginx.pid;

env ON_AZURE=1;
env awsaccesskeyid=something;
env awssecretkey=something;

events {
        worker_connections 1024;
        multi_accept on;
        use epoll;
}

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;
        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
        ##
        gzip on;
        gzip_disable "msie6";

        # gzip_vary on;
        # gzip_proxied any;
        # gzip_comp_level 6;
        # gzip_buffers 16 8k;
        # gzip_http_version 1.1;
        # gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascrip$

        ##
        # nginx-naxsi config
        ##
        # Uncomment it if you installed nginx-naxsi
        ##

        #include /etc/nginx/naxsi_core.rules;

        ##
        # nginx-passenger config
        ##
        # Uncomment it if you installed nginx-passenger
        ##

        #passenger_root /usr;
        #passenger_ruby /usr/bin/ruby;

        ##
        # Virtual Host Configs
        ##

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}


#mail {
#       # See sample authentication script at:
#       # http://wiki.nginx.org/ImapAuthenticateWithApachePhpScript
#
#       # auth_http localhost/auth.php;
#       # pop3_capabilities "TOP" "USER";
#       # imap_capabilities "IMAP4rev1" "UIDPLUS";
#
#       server {
#               listen     localhost:110;
#               protocol   pop3;
#               proxy      on;
#       }
#
#       server {
#               listen     localhost:143;
#               protocol   imap;
#               proxy      on;
#       }
#}

What's going on?

Note: please ask me for more information in case you need it, e.g. how my gunicorn.conf and nginx.conf looks, packages installed or if you need something db related. Just ask away!

Answer 1

You are not forwarding proxy IP. Here is my set of forwarded headers I set in my nginx config:

location / {
    proxy_set_header    Host                    $http_host;
    proxy_set_header    User-Agent              $http_user_agent;
    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;
    proxy_pass          ......;
}

More options in nginx docs - http://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_set_header

Then in Django you can do:

user_ip = request.META['HTTP_X_REAL_IP`] or request.META['REMOTE_ADDR']

Note that X-Forwarded-Proto is necessary when using Django with SSL in which case you will also need to configure Django a bit:

SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')

More in Django docs - https://docs.djangoproject.com/en/1.9/ref/settings/#std:setting-SECURE_PROXY_SSL_HEADER