@bponsler, We have cloned diagnostic_updater from ROS1 master (Indigo-devel) branch and merged your changes from bponsler:ros2-devel branch. Additionally we have updated some CPP code as per ROS2 guidelines to support ROS2 build and also execute gtest on ROS2 Bouncy.
@bponsler, @Austin Hendrix, @Brice Rebsamen, As diagnostics git repo is not available for ROS2, Would you please suggest us to whom we should raise PR for the same.