apache-le-ssl.conf

# Overleaf let's encrypt reverse proxy configuration file for apache2 webserver

<VirtualHost *:443>
	# The ServerName directive sets the request scheme, hostname and port that
	# the server uses to identify itself. This is used when creating
	# redirection URLs. In the context of virtual hosts, the ServerName
	# specifies what hostname must appear in the request's Host: header to
	# match this virtual host. For the default virtual host (this file) this
	# value is not decisive as it is used as a last resort host regardless.
	# However, you must set it for any further virtual host explicitly.
	ServerName overleaf.example.com

	ServerAdmin sysadmin@example.com
	DocumentRoot /var/www/html

	# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
	# error, crit, alert, emerg.
	# It is also possible to configure the loglevel for particular
	# modules, e.g.
	#LogLevel info ssl:warn

	ErrorLog ${APACHE_LOG_DIR}/error-overleaf.log
	CustomLog ${APACHE_LOG_DIR}/access-overleaf.log combined

    RewriteEngine On
    RewriteCond %{HTTP:Upgrade} =websocket [NC]
    RewriteRule /(.*)           ws://127.0.0.1:8080/$1 [P,L]
    RewriteCond %{HTTP:Upgrade} !=websocket [NC]
    RewriteRule /(.*)           http://127.0.0.1:8080/$1 [P,L]

    <IfModule mod_proxy.c>
        ProxyRequests Off
        ProxyPassReverse / http://127.0.0.1:8080/
    </IfModule>

    <IfModule mod_ssl.c>
        SSLCertificateFile /etc/letsencrypt/live/overleaf.example.com/fullchain.pem
        SSLCertificateKeyFile /etc/letsencrypt/live/overleaf.example.com/privkey.pem
        Include /etc/letsencrypt/options-ssl-apache.conf
    </IfModule>


    # To avoid SSL stripping https://en.wikipedia.org/wiki/SSL_stripping#SSL_stripping
    Header always set Strict-Transport-Security "max-age=31536000; includeSubdomains;"

    #ServerTokens Prod
    LimitRequestBody 52428800

    <Location />
        ProxyAddHeaders On
        RequestHeader set X-Forwarded-Proto "https"
        RequestHeader set X-Forwarded-For "%{REMOTE_ADDR}s"
        RequestHeader set Host "%{HTTP_HOST}e"
    </Location>
</VirtualHost>