This addresses the surprising behavior that the StoreBoxMetadata hook
was running many times during a machine up, including during failed
operations where a destroy_on_error deleted the machine. This was
resulting in an error that looked like:
> No such file or directory @ rb_sysopen [...] /[...]/box_meta
Plugin action hooks using prepend/append were attaching every time a
Builder was run, including sub-Builders that show up for things like
Call actions.
To fix this, we tell Builders if they are "primary" and only run
prepend/append on those. See inline comments for more explanation.
This adjusts how triggers are implemented during a normal run. Any
defined triggers which are applicable are located and injected into
the run stack as the stack is built, including hook type triggers.
Support is included for dynamic hook lookup.
The data type used when defining triggers has also been relaxed to
support symbols, strings, or constants.
This commit introduces some basic functionality for typed triggers:
- command
- action
Command triggers are triggers that will run before or after a given
sub-command.
Action triggers are for running triggers before or after internal
actions for Vagrant. This could be before or after a provision step,
before or after synced folders, or networking, etc.
I found this output to be very helpful in debugging an action hook
problem in a plugin. problem. I'm not sure why the callable_id is
useful (seem to always show up as an instance of `Builder` or `Warden`
for me), but I left it in there just in case it's useful to someone.
This can be removed since in the future all actions will come from the
providers or something. There are still issues with box actions but
we'll get back to that later...
