Docker led me astray.  The dockerfile let me declare an environment variable section with dotted name variables such as:

x.y.z=value

But this is not normally allowed syntax for an environment variables.  I didn't have a problem until I tried using a non-dockerized version of the spring-boot application, and I found I couldn't set the environment properly to run the app.  The solution is easy which is to change the expectation on the environment variables seen into the traditional form of:

X_Y_Z=value.

This change only affects 2 variables used during app initialization.