Migration handlers: the smart strategy

[vincent-zurczak]

This strategy is so smart that I have not found it yet. And it will most likely require some research work about it, and maybe some new features in Roboconf.

[vincent-zurczak]

This strategy is not global, but requires to specify the components on which an action is required. So, basically, it is key-value. Two options for a given component:

• Default: (stateless assumed). We create an instance of a given component, we delete an old one. Etc.
• We execute a script that will perform an action on this component.