Keeping servers consistent.
WHAT THE PROBLEM IS
Servers configured by hand diverge over time.
WHAT THAT CAUSES
Problems on one server and not another, with no explanation.
WHAT CONFIGURATION MANAGEMENT DOES
Describes the intended state, and makes the server match it.
WHAT TOOLS PROVIDE
Repeatable application of configuration Detection of drift Version-controlled descriptions
WHAT A SMALL TEAM CAN DO
Setup scripts, committed to version control.
WHY THAT COUNTS
It is repeatable, versioned and reviewable.
WHAT TO DESCRIBE
Packages installed Configuration files Users and permissions Scheduled tasks Firewall rules
WHAT TO NEVER DO
Make a manual change to something described in code.
WHY
The next application of the configuration reverses it, confusingly.
WHAT TO DO INSTEAD
Change the description, then apply it.
WHAT TO CHECK PERIODICALLY
Whether the actual state matches the intended one.
WHAT TO RECORD
Why each setting is what it is.
