hedgedoc/docs/content/guides/reverse-proxy.md

Using a Reverse Proxy with HedgeDoc

If you want to use a reverse proxy to serve HedgeDoc, here are the essential configs that you'll have to do.

This documentation will cover HTTPS setup, with comments for HTTP setup.

Cloudflare

!!! warning If you use Cloudflare as reverse proxy then you MUST disable the minify features for HTML, CSS and JS, or your HedgeDoc instance may be broken. For more information please read the Cloudflare documentation.

HedgeDoc config

Useful configuration options

config.json parameter	Environment variable	Value	Example
domain	CMD_DOMAIN	The full domain where your instance will be available	hedgedoc.example.com
host	CMD_HOST	An ip or domain name that is only available to HedgeDoc and your reverse proxy	localhost
port	CMD_PORT	An available port number on that IP	3000
path	CMD_PATH	path to UNIX domain socket to listen on (if specified, host or CMD_HOST and port or CMD_PORT are ignored)	/var/run/hedgedoc.sock
protocolUseSSL	CMD_PROTOCOL_USESSL	true if you want to serve your instance over SSL (HTTPS), false if you want to use plain HTTP	true
useSSL		false, the communications between HedgeDoc and the proxy are unencrypted	false
urlAddPort	CMD_URL_ADDPORT	false, HedgeDoc should not append its port to the URLs it links	false
hsts.enable	CMD_HSTS_ENABLE	true if you host over SSL, false otherwise	true

Full explanation of the configuration options

Configure asset link generation

HedgeDoc generates links to other pages and to assets (like images, stylesheets, fonts, etc) using the following settings. You must configure them according to the URL that you use to access your instance.

• domain (env: CMD_DOMAIN)
• protocolUseSSL (env: CMD_PROTOCOL_USESSL)
• urlAddPort (env: CMD_URL_ADDPORT)

!!! example You access your HedgeDoc instance using a reverse proxy via https://markdown.example. You must set:

- `domain` to `markdown.example`.
- `protocolUseSSL` to `true` because you access your instance via HTTPS.
- `urlAddPort` to `false` because you access the instance using the default HTTPS port.

Reverse Proxy config

Generic

The reverse proxy must allow websocket Upgrade requests at path /sockets.io/.

It must pass through the scheme used by the client (http or https).

Nginx

Here is an example configuration for Nginx.

map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
}
server {
        server_name hedgedoc.example.com;

        location / {
                proxy_pass http://127.0.0.1:3000;
                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;
        }

        location /socket.io/ {
                proxy_pass http://127.0.0.1:3000;
                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_set_header Upgrade $http_upgrade;
                proxy_set_header Connection $connection_upgrade;
        }

    listen [::]:443 ssl http2;
    listen 443 ssl http2;
    ssl_certificate fullchain.pem;
    ssl_certificate_key privkey.pem;
    include options-ssl-nginx.conf;
    ssl_dhparam ssl-dhparams.pem;
}

Apache

You will need these modules enabled: proxy, proxy_http and proxy_wstunnel.
Here is an example config snippet:

<VirtualHost *:443>
  ServerName hedgedoc.example.com

  RewriteEngine on
  RewriteCond %{REQUEST_URI} ^/socket.io             [NC]
  RewriteCond %{HTTP:Upgrade} =websocket             [NC]
  RewriteRule /(.*)  ws://127.0.0.1:3000/$1          [P,L]

  ProxyPass / http://127.0.0.1:3000/
  ProxyPassReverse / http://127.0.0.1:3000/

  RequestHeader set "X-Forwarded-Proto" expr=%{REQUEST_SCHEME}
        
  ErrorLog ${APACHE_LOG_DIR}/error.log
  CustomLog ${APACHE_LOG_DIR}/access.log combined

  SSLCertificateFile /etc/letsencrypt/live/hedgedoc.example.com/fullchain.pem
  SSLCertificateKeyFile /etc/letsencrypt/live/hedgedoc.example.com/privkey.pem
  Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>