server {
    # Make this the default server that is used to process a request
    # where the HOST header does not match the server's server_name
    # directive. Used to prevent host spoofing.
    # Immediately closes the connection.

    listen 80 default_server;
    return 444;
}

upstream app_server {
    # This directive defines how requests are passed to Gunicorn.

    # fail_timeout=0 means we always retry an upstream even if it failed
    # to return a good HTTP response

    # For UNIX domain socket setups, i.e. your app runs on the same
    # machine with NGINX
    # server unix:/tmp/gunicorn.sock fail_timeout=0;

    # For a TCP configuration use IP address instead. Example use
    # would be running NGINX and your app in two different containers
    server 127.0.0.1:8000 fail_timeout=0;
}

server {
    # Use 'listen 80 deferred;' for Linux.
    # This prevents the process from being woken up until there's a
    # packet with real data for it to process.
    listen 80 deferred;
    client_max_body_size 4G;

    # Setting localhost as the server name for now, change this to
    # your hostname accordingly, or IP address if running on a server
    # without a hostname.
    server_name localhost;

    keepalive_timeout 5;

    # The path from which static files are served.
    # We don't have any in the app right now, but it would likely be
    # this for now.
    root /opt/sensorapp/sensorapp/static/;

    location / {
        # Checks for static file. If not found, use the proxy_to_app
        # location to process the request.
        try_files $uri @proxy_to_app;
    }

    location @proxy_to_app {
        # These are headers that allow our app to know more about
        # the original request that was sent.
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Host $http_host;
        # we don't want nginx trying to do something clever with
        # redirects, we set the Host: header above already.
        proxy_redirect off;

        # This line passes the request on to the address defined
        # by the upstream directive above.
        proxy_pass http://app_server;
    }

    # Serve a custom error 500 page from the app's static folder.
    # Commented out since we don't actually have one.
    # error_page 500 502 503 504 /500.html;
    # location = /500.html {
    #    root /opt/sensorapp/sensorapp/static/;
    # }
}