====== Mattermost ======
Apache :
<code><VirtualHost *:443>
Protocols h2 http/1.1

ServerAdmin webmaster@FQDN
DocumentRoot "/var/www/html/"
ServerName FQDN
ProxyPreserveHost On

# Set web sockets
RewriteEngine On

RewriteCond %{REQUEST_URI} /api/v[0-9]+/(users/)?websocket [NC,OR]
RewriteCond %{HTTP:UPGRADE} ^WebSocket$ [NC,OR]
RewriteCond %{HTTP:CONNECTION} ^Upgrade$ [NC]
RewriteRule .* ws://127.0.0.1:8065%{REQUEST_URI} [P,QSA,L]

<Location />
  Require all granted
  ProxyPass http://127.0.0.1:8065/
  ProxyPassReverse http://127.0.0.1:8065/
  ProxyPassReverseCookieDomain 127.0.0.1 FQDN</Location>

ErrorLog "/var/log/apache2/FQDN_error.log"
CustomLog "/var/log/apache2/FQDN_access.log" combined

SSLCertificateFile /etc/letsencrypt/live/FQDN/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/FQDN/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
</VirtualHost>
</code>