Disciplinarian

[Hina Muqadas]

One who disciplines; one who excels in training,
especially with training, especially with regard to order and
obedience; one who enforces rigid discipline; a stickler for the
observance of rules and methods of training; as, he is a better
disciplinarian than scholar.

[Mark Zuckerberg]

[someone] who demands exact [conformity] to [rules] and forms

[Dave Paprocki]

A person who believes in or practises firm discipline.

[Michiko]

someone who believes in keeping complete control of the people he or she is in charge of, especially by giving severe punishments: