Composition Diamond lemma for Lie algebra over a field $F$ has already been investigated in several papers :

L.Bokut and Y.Q.Chen Groebner-Shirshov bases for Lie algebras

and

A.I Shirshov, Some algorithmic problems for Lie algebras

I am looking for a paper including composition lemma for the case of Leibniz algebras? I appreciate your comments and your time in advance.