Modern applications have embraced separation of concerns as a first-order organizing principle through the use of containers, container orchestration, and service meshes. However, adaptation to unexpected network variation has not followed suit. We present BumbleBee, a lightweight extension to the container ecosystem that supports application-aware adaptation. BumbleBee provides a simple abstraction for making decisions about network data using application semantics. Because this abstraction is placed within the communications framework of a modern service mesh, it is closer to the point at which changes are detected, providing more responsive and effective adaptation than possible at endpoints.