  We use Gaia Data Release 2 to determine the mean proper motions for 150 Milky
Way globular clusters (almost the entire known population), with a typical
uncertainty of 0.05 mas/yr limited mainly by systematic errors. Combining them
with distance and line-of-sight velocity measurements from the literature, we
analyze the distribution of globular clusters in the 6d phase space, using both
position/velocity and action/angle coordinates. The population of clusters in
the central 10 kpc has a mean rotational velocity reaching 50-80 km/s, and a
nearly isotropic velocity dispersion 100-120 km/s, while in the outer galaxy
the cluster orbits are strongly radially anisotropic. We confirm a
concentration of clusters at high radial action in the outer region of the
Galaxy. Finally, we explore a range of equilibrium distribution function-based
models for the entire globular cluster system, and the information they provide
about the potential of the Milky Way. The dynamics of clusters is best
described by models with the circular velocity between 10 and 50 kpc staying in
the range 210-240 km/s.
