fd1, fd2, rc for CLI API

[Zeebrow]

Description

Plugin functions whose return values are handled by main.py's cli_main() function need to return appropriate values for stderr, stdout and rc.

• Animation vs. static text
  • detect file vs tty output
  • imagine apt output to a file:

    Reading dependencies!... 10%
    Reading dependencies!... 30%
    Reading dependencies!... 30%
    ...

• Plan for varying verbosity levels.
• Always aim for less verbosity than Ansible

create

• wait_for_hosts is animated

destroy

• wait_for_hosts is animated

update

• asdkfueyaaes
• I don't wanna talk about it

describe

I think a good starting point is outputting some json to sys.stdout., logging warnings/errors with logging.StreamHandler (defaults to sys.stderr, fd 2, for all log methods, at all log levels), and setting rc=0 if there are none.

Working with file-like output also implies some different scenarios for handling file descriptors (Linux) and whatever (Windows):

1. main.py passes file descriptors to the plugin's describe method, and the plugin does the printing
   • Each plugin would potentially output differently, but each plugin will have a different definition of what properties describe an 'app'.
   • gives plugin the opportunity to log to something like Cloudwatch or S3
2. main.py receives a class instance from the plugin
   • plugins would need to implement or subclass from the quickhost package, which does not exist.
   • Simpler plugins (I like)
   • Standardized output format

After talking it over with myself, I think this guy has some really good ideas, regarding 2). Either way, I'm not just throwing it in a dict as the api's end result.