  We construct special Lagrangian fibrations for log Calabi-Yau surfaces, and
scattering diagrams from Lagrangian Floer theory of the fibres. Then we prove
that the scattering diagrams recover the scattering diagrams of
Gross-Pandharipande-Siebert and the canonical scattering diagrams of
Gross-Hacking-Keel. With an additional assumption on the non-negativity of
boundary divisors, we compute the disc potentials of the Lagrangian torus
fibres via a holomorphic/tropical correspondence. As an application, we provide
a version of mirror symmetry for rank two cluster varieties.
