eigenvalues eigenvectors - Eigen values of special matrix

I have a matrix $A \in \mathbb{R}^{n\times n}$ whose diagonal elements are all "$1$" and all other elements are of the form $\frac{-1}{n}$ where $n \in \mathbb{N}$ and $n >1$ is the number of rows or columns of $A$. Since $A$ is symmetric and diagonally dominant with positive diagonal entries, it is positive definite.

Can we get an expression for its eigenvalues using some kind of decomposition or by other standard approach ?

This matrix clearly has a special structure but I am unable to utilize its properties.