I'm trying to change my workflow to create change sets. I have a set of nested stacks with a bunch of parameters, and I want to specify that all parameters use the existing values.
I can see that there is an option on a parameter by parameter basis to set UsePreviousValue=true but I would have to do that on every one of my parameters. This is particularly frustrating because in the same CLI, the call to aws cloudformation deploy uses the existing parameters by default.
I may have answered my own question. It appears as though this is not possible. And
aws cloudformation deploydoes not support nested-stack change sets. Ugh.