  We consider cohomogeneity one homogeneous disk bundles and adress the
question when these admit a nonnegatively curved invariant metric with normal
collar, i.e., such that near the boundary the metric is the product of an
interval and a normal homogeneous space. If such a bundle is not (the quotient
of) a trivial bundle, then we show that its rank has to be in $\{2,3,4,6,8\}$.
Moreover, we give a complete classification of such bundles of rank 6 and 8,
and a partial classification for rank 3.
