Environment variable ATL_AUTOLOGIN_COOKIE_AGE can be passed to a Confluence instance running on a docker container - this one implements the change on parameter

autologin.cookie.age on <confluence-install>/confluence/WEB-INF/classes/seraph-config.xml

However, as per KB How to adjust the session timeout for Confluence , we may still need to change parameters on two other files:

• {}session-config{{ / session-timeout}} on <confluence-install>/conf/web.xml 
• {}session-config{{ / session-timeout}} on <confluence-install>/confluence/WEB-INF/web.xml

However, we do not have any environment variables to configure those settings and would be important to have.