This guide provides a basic overview for installing Drone server behind the nginx webserver. For more advanced configuration options please consult the official nginx documentation.
Example configuration:
map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}
server {
    listen 80;
    server_name drone.example.com;
    location / {
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Host $http_host;
        proxy_pass http://127.0.0.1:8000;
        proxy_redirect off;
        proxy_http_version 1.1;
        proxy_buffering off;
        chunked_transfer_encoding off;
    }
    location ~* /ws {
        proxy_pass http://127.0.0.1:8000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_read_timeout 86400;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header Host $http_host;
    }
}
You must configure the proxy to set X-Forwarded proxy headers:
map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}
server {
    listen 80;
    server_name drone.example.com;
    location / {
+       proxy_set_header X-Forwarded-For $remote_addr;
+       proxy_set_header X-Forwarded-Proto $scheme;
        proxy_pass http://127.0.0.1:8000;
        proxy_redirect off;
        proxy_http_version 1.1;
        proxy_buffering off;
        chunked_transfer_encoding off;
    }
    location ~* /ws {
        proxy_pass http://127.0.0.1:8000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_read_timeout 86400;
+       proxy_set_header X-Forwarded-For $remote_addr;
+       proxy_set_header X-Forwarded-Proto $scheme;
    }
}
You must configure Nginx to upgrade websockets.
+map $http_upgrade $connection_upgrade {
+    default upgrade;
+    ''      close;
+}
server {
    listen 80;
    server_name drone.example.com;
    location / {
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_pass http://127.0.0.1:8000;
        proxy_redirect off;
        proxy_http_version 1.1;
        proxy_buffering off;
        chunked_transfer_encoding off;
    }
    location ~* /ws {
        proxy_pass http://127.0.0.1:8000;
        proxy_http_version 1.1;
+       proxy_set_header Upgrade $http_upgrade;
+       proxy_set_header Connection "upgrade";
        proxy_read_timeout 86400;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}