Questions[gunicorn](server)

I am getting Invalid HTTP_HOST header error on my server. I don't understand why it's happening and how to fix it. Everytime it happens backend stops working and I have to restart the server.

Any help will be appreciated.

Thanks in advance!

FYI : Server is aws ec2; frontend is angular and backend is django/drf with gunicorn. Angular and DRF are both deployed on the same server.

Error 0. If I don't set the Host variable in nginx.conf, I get below error many times. Invalid HTTP_HOST header: '/run/gunicorn.sock:'. The domain name provided is not valid according to RFC 1034/1035.

If I set the Host variable in nginx.conf, I get below errors.

Error 1. proxy_set_header Host $http_host;

Invalid HTTP_HOST header: '127.0.0.1:8000,127.0.0.1:8000'. The domain name provided is not valid according to RFC 1034/1035.

Error 2. proxy_set_header Host $host;

Invalid HTTP_HOST header: '127.0.0.1:8000,127.0.0.1'. The domain name provided is not valid according to RFC 1034/1035.

Error 3. proxy_set_header Host $server_name;

Invalid HTTP_HOST header: '13.234.187.18,13.234.187.18:8000'. The domain name provided is not valid according to RFC 1034/1035.

nginx.conf is as below.

server {
    listen 8000;
    server_name 13.234.187.18;

    location / {
        proxy_set_header Host $host;
        include proxy_params;

        proxy_pass http://unix:/run/gunicorn.sock;
    }
}

I found below code on the nginx website. Will it solve this problem? http://nginx.org/en/docs/http/request_processing.html

server {
    listen      80;
    server_name "";
    return      444;
}

I have an automated deployment workflow that pushes code out to my production servers and triggers database migrations, static file updates, etc. Problem is, gunicorn doesn't automatically reload code changes without the development option --reload, which they recommend not using in production. Instead the instruction is to send an HUP signal to the masterpid. Problem is, I don't know how to retrieve the masterpid in an automated script, though it is easy enough to do manually.

How can I retrieve the materpid value for the gunicorn systemd process in a bash script?

Our app's REST API is served by Gunicorn (not behind Nginx) running on AWS EC2 instances with a typical auto-scaling/load balancing setup. The load balancer's idle timeout is 60 seconds, and Gunicorn's keep-alive timeout is 2 seconds. We've been seeing sporadic 504 Gateway Timeout responses from this configuration. According to Amazon docs, this may be because the server's keep-alive timeout is lower than the load balancer's idle timeout setting:

Cause 2: Registered instances closing the connection to Elastic Load Balancing.

Solution 2: Enable keep-alive settings on your EC2 instances and set the keep-alive timeout to greater than or equal to the idle timeout settings of your load balancer.

With Nginx, the default keepalive_timeout is 75 seconds, which apparently works well with the ELB default settings. However, Gunicorn docs recommend a keepalive setting in the range of 1-5 seconds.

Does it make sense to bump Gunicorn's keepalive to 75 seconds, or is there a good reason for keep it below 5 seconds even though we're not using a reverse proxy in front of it?

this is my first web app deployment and am running into all sorts of issues.

I am currently going for a nginx + gunicorn implementation for the Django app, but mostly this question relates to nginx configurations. For some context - nginx would receive connections and proxy to the gunicorn local server.

in the nginx configurations, where it says server_name do I have to provide one? I don't plan to use domain names of any kind, just through my network's external ip (it is static) and the port number to listen to.

My desire is that when I access something like http://xxx.xxx.xxx.xxx:9050 I would be able to get the site.

The following is the sample code that I will base the configurations on for reference.

   server {
        listen   80;
        server_name WHAT TO PUT HERE?;

    root /path/to/test/hello;

    location /media/ {
        # if asset versioning is used
        if ($query_string) {
            expires max;
        }
    }
    location /admin/media/ {
        # this changes depending on your python version
        root /path/to/test/lib/python2.6/site-packages/django/contrib;
    }
    location / {
        proxy_pass_header Server;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Scheme $scheme;
        proxy_connect_timeout 10;
        proxy_read_timeout 10;
        proxy_pass http://localhost:8000/;
    }
        # what to serve if upstream is not available or crashes
        error_page 500 502 503 504 /media/50x.html;
     }

I have a problem deploying Django app using Gunicorn and Supervisor. While I can make Gunicorn serving my app (by setting proper PYTHONPATH and running apropriate command, the one from supervisord config) I can't make supervisor to run it. It just won't see my app. I don't know how to make sure if the config file is ok.

Here's what supervisorctl says:

# supervisorctl start myapp_live
myapp_live: ERROR (no such process)

I'm running it on Ubuntu 10.04 with following config:

File /home/myapp/live/deploy/supervisord_live.ini:

[program:myapp_live]
command=/usr/local/bin/gunicorn_django --log-file /home/myapp/logs/gunicorn_live.log --log-level info --workers 2 -t 120 -b 127.0.0.1:10000 -p deploy/gunicorn_live.pid webapp/settings_live.py
directory=/home/myapp/live
environment=PYTHONPATH='/home/myapp/live/eco/lib'
user=myapp
autostart=true
autorestart=true

In /etc/supervisor/supervisord.conf, at the end of the file, there is:

[include]
files = /etc/supervisor/conf.d/*.conf

and here's a symlink to my config file:

# ls -la /etc/supervisor/conf.d
lrwxrwxrwx 1 root root   48 Dec  4 18:02 myapp-live.conf -> /home/myapp/live/deploy/supervisord_live.ini

everything looks fine for me but supervisorctl just keep saying myapp_live: ERROR (no such process). Any solution for this?