Need a Single Definition for a Variable to be used by Deployment Environments w/i a Project

[Martin Bruegel]

Running Bamboo 6.8.1

I understand the general concepts of variable inheritance:

• Global
• Plan
• Build  (can be overridden w/ a manual build)
• Release (takes snapshots of global and plan variables)
• Deployment

My problem is that I have a single plan-level variable (password property) which needs to be evaluated at run time-time for a deployment. 

The release takes a snapshot of the plan variables (so if the value of my plan variable needs to change) the snapshot value in the release, which is stale / out of sync overrides it,

Yes, I know I can define a deployment environment variable -- but I have several deployment environments (11), so setting a variable value 11x vs once is not scalable for my project.

Basically looking for any *one* of the following:

• ability to back reference a higher-level (overridden) variable
• ability to reference a specified deployment variable from a specified environment  across different environments in the same project
• ability to bulk set / define a core deployment-level variable across multiple deployment environments w/i a given project

Any suggestions would be appreciated.