Apache

1) Enable Mod_Proxy

sudo a2enmod ssl proxy proxy_http proxy_wstunnel proxy_balancer

Apache Mod_Proxy documentation

2) Restart Apache

Systemd:

sudo systemctl restart apache2

Init.d:

sudo service apache2 restart

3) Enable SSL in Apache config

Listen 443

NameVirtualHost *:443

4) Set Apache proxy

a) Main URL

SSL with Certbot.

Config at /etc/apache2/sites-available/example.com.conf:

<VirtualHost *:443>

    ServerName example.com

    SSLEngine On
    SSLCertificateFile      /etc/letsencrypt/live/example.com/fullchain.pem
    SSLCertificateKeyFile   /etc/letsencrypt/live/example.com/privkey.pem
    Include /etc/letsencrypt/options-ssl-apache.conf
    ServerSignature Off

    <Location />
     require all granted
    </Location>

    ProxyPassMatch   "^/(sockjs\/.*\/websocket)$" "ws://127.0.0.1:3001/$1"
    ProxyPass        "/" "http://127.0.0.1:3001/"
    ProxyPassReverse "/" "http://127.0.0.1:3001/"

</VirtualHost>

b) Sub URL

Config at /etc/apache2/sites-available/example.com.conf:

<VirtualHost *:443>

    ServerName example.com/wekan

    SSLEngine On
    SSLCertificateFile      /etc/letsencrypt/live/example.com/fullchain.pem
    SSLCertificateKeyFile   /etc/letsencrypt/live/example.com/privkey.pem
    Include /etc/letsencrypt/options-ssl-apache.conf
    ServerSignature Off

    ProxyPassMatch   "^/(sockjs\/.*\/websocket)$" "ws://127.0.0.1:3001/wekan/$1"
    ProxyPass        "/wekan" "http://127.0.0.1:3001/wekan"
    ProxyPassReverse "/wekan" "http://127.0.0.1:3001/wekan"

</VirtualHost>

To run as default site:

<VirtualHost _default_:443>

5) Enable your site

sudo a2ensite example.com

Or, add symlink manually:

sudo su

cd /etc/apache2/sites-enabled

ln -s ../sites-available/example.com.conf example.com.conf

On some distros Apache config is at different path:

cd /etc/httpd/conf.d

6) Reload Apache

Systemd:

sudo systemctl restart apache2

Init.d:

sudo service apache2 restart

7) Snap settings

a) Main URL

sudo snap set wekan port='3001'

sudo snap set wekan root-url='https://example.com'

b) Sub URL

snap set wekan port='3001'

snap set wekan root-url='https://example.com/wekan'

All snap settings