Odoo 9 Apache2 Reverse Proxy SSL

Prerequisite: Apache2 enabled
Enabling Apache2 module
# a2enmod proxy_http headers remoteip rewrite
To enable Apache2 cache to disk
# a2enmod cache cache_disk
Edit Default Virtual Host for SSL
# vi /etc/apache2/sites-available/default-ssl.conf
...
ProxyRequests off
SSLProxyEngine on
SSLEngine on
RequestHeader set "X-Forwarded-Proto" "https"
SetEnv proxy-nokeepalive 1
Proxypass "/" "http://localhost:8069/" # 127.0.0.1
ProxyPassReverse "/" "http://localhost:8069/" # 127.0.0.1
ProxyErrorOverride off
...
Restart Apache2
# /etc/init.d/apache2 restart
Run Odoo for localhost only
# vi /etc/odoo/openerp-server.conf
...
proxy_mode = true
xmlrpc_interface = 127.0.0.1
...
Restart Odoo
# /etc/init.d/odoo restart
References:

• https://httpd.apache.org/docs/2.4/howto/reverse_proxy.html 
• https://httpd.apache.org/docs/2.4/mod/mod_proxy.html 
• http://www.wirasoenaryo.com/how-to-use-apache-as-reverse-proxy-on-odoo/ 
• https://www.leaseweb.com/labs/2014/12/tutorial-apache-2-4-transparent-reverse-proxy/ 
• https://www.odoo.com/forum/help-1/question/how-to-set-up-odoo-8-with-ssl-and-apache2-61282 
• https://www.digitalocean.com/community/tutorials/how-to-configure-apache-content-caching-on-ubuntu-14-04