Best practices for configuration files

The Control Center configuration file, /etc/default/serviced, contains Bash environment variables that are read by the serviced daemon startup script. The following list describes recommended best practices for its use and maintenance:

  1. When in doubt, make a backup. Before editing, making a backup copy of the configuration file is always the safest choice.
  2. Copy a variable, then edit the copy. If you need to revert a variable to its default value, you don't have to leave the file to look it up.
  3. Copy and edit a variable only if the default value needs to be changed. It's easier to troubleshoot problems when only non-default variables are copied and edited.
  4. Put the first character of the variable declaration in the first column of its line. It's easier to grep for settings when each one starts a line.
  5. Add customizations to the top of the file. Customizations at the end of the file or scattered throughout the file may be overlooked.
  6. In high-availability deployments, the contents of /etc/default/serviced on the master nodes must be identical. Use a utility like sum to compare the files quickly.