nginx.conf

upstream vaultwarden { server localhost:1024; }
upstream vaultwarden-ws { server localhost:3012; }

server {
    listen 80;
    listen [::]:80;
    server_name subdomain.domain.com;
    server_tokens off;

    location /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }

    location / {
        return 301 https://$host$request_uri;
    }
}

server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name subdomain.domain.com;
    server_tokens off;

    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;

    ssl_certificate /etc/letsencrypt/live/subdomain.domain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/subdomain.domain.com/privkey.pem;
    include /etc/letsencrypt/options-ssl-nginx.conf;
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;

    client_max_body_size 128M;

    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;

        proxy_pass http://vaultwarden;
    }

    location /notifications/hub/negotiate {
        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;

        proxy_pass http://vaultwarden;
    }

    location /notifications/hub {
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $http_connection;
        proxy_set_header X-Real-IP $remote_addr;

        proxy_pass http://vaultwarden-ws;
    }

    location /admin {
        auth_basic "Private";
        auth_basic_user_file /etc/nginx/htpasswd/.htpasswd;

        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;

        proxy_pass http://vaultwarden;
    }
}