Write the Laplacian operator in a particular coordinate system

Question

I have to write the differential operator the Laplacian, divergence, gradient in the following curvilinear coordinate system: $$\left \{ \begin{array}{rl} x=(R_0+r\cos\theta )\cos\phi\\ y=(R_0+r\cos\theta )\sin\phi \\ z=r\sin\theta \end{array} \right.$$ with $R_0>0$. I managed to find $$ds^2=dr^2+r^2d\theta^2+(R_0+r\cos\theta)^2 d\phi^2$$ for the determination of the factors $h_1,h_2, h_3$ to put inside the general formula for an orthogonal curvilinear coordinate system. Is it correct? Any help?