How to add custom variable name with apache logs so that I can add my project name with my error logs in beginning, it is helpful for recognizing error logs with project name. I have lot of projects in my organization and project can be build in any language, I want to track all logs on a one place, but issue is that which errors are coming from which projects, i am unable to get it, so I want to add project name with logs. please suggest me, if any documentation is there, so i can manipulate apache then share with me.