support running curtin in with debug

[Scott Moser]

would be nice to be able to make a change to maas to be albe to run curtin with debug enabled.
that would allow people to see more debug output of curtin on the console at least.
also nice would be to run with --showtrace.

currently this can only be accomplished by changing maas region controller's
  /usr/lib/python2.7/dist-packages/curtin/pack.py

the method 'pack_install' there just needs:
- command = ["curtin", "install"]
+ command = ["curtin", "-vv", "install"]

currently curtin's config cannot enable debug log or showtrace, so I'll add a task for that also.

[Scott Moser (smoser)]

Added this to curtin.
now you can add to your curtin config somethin glike:

    verbosity: 3
    showtrace: true

and get the equivalent of '-vvv' and '--showtrace'

[Mike Pontillo (mpontillo)]

Question: what is the disadvantage of enabling debugging?

Why would users *not* want to always see the additional output?

[Mike Pontillo (mpontillo)]

Ah, I think I answered my own question. (the verbose output contains the maas-metadata-credentials.)

[Scott Moser (smoser)]

This bug is believed to be fixed in curtin in 17.1. If this is still a problem for you, please make a comment and set the state back to New

Thank you.