Cloned from launchpad blueprint https://blueprints.launchpad.net/heat/+spec/stack-breakpoint.

Description:

Troubleshooting a failed stack can be quite difficult. During development, debugging failed template is simply part of the process, but in production, a previously working template can also fail for many reasons. Providing support for troubleshooting template will not only increase productivity but will also help the adoption of Heat template.  Currently a stack is stopped after a resource fails in the create step, but this may be too late or too hard to debug because the original cause of the failure may not be obvious or the environment may have been changed.  If we can pause the stack at a point before the failure, then we are in a better position to troubleshoot.  For instance, we can check whether the state of the environment and the stack is what we expect, we can manually run the next step to see how it fails, etc. 
While developing new template or resource type, it is also useful to bring up a stack to a point before the new code is to be executed.  Then the developer can manually execute and debug the new code. 

Specification URL (additional information):

None