$ juju switch --format

[Tim Penhey]

On 06/06/14 09:55, Jesse Meek wrote:
> I have a branch proposed that displays extra environment information
> when the --format flag is used with switch e.g:
> 
> $ juju switch local --format yaml
> environ-name: local
> previous-environ-name: ec2
> state-servers:
>     - example.com
>     - kremvax.ru
> username: joe
> 
> There is some debate over this. Roger has summarised the key issues well
> in his review comment:
> 
> "I think this is a bit odd. In every other command AFAIK, choosing a
> format does not affect the actual information displayed, just the format
> that it's printed in.
> 
> Why are we printing all this info with the "switch" command anyway?
> Personally I'd think that a new command was warranted here, perhaps
> "juju current", or "juju show" or "juju info"."

I was going to comment on the pull request, but since it has been
brought to the list, I will do it here and now.

This change has grown and grown, and become somewhat of a moving target.

The original request was:
   "output the user for the environment when switching"

I take some of the blame for this by not splitting the command up when I
initially wrote it.

'switch' has an alias of 'env' and I always ended up using
   juju env
to see what my current environment was, and
   juju switch
to change it.  This alone should have told me that I should have changed
it, but I didn't.

The core reason that the information is different at this stage is that
we don't want to break any existing clients, but we do want to lay the
foundations for changing the output on the next release.

The idea that the output from the CLI may be being used and parsed by
scripts.  This was one of the key reasons to add the formatting options.

> My first implementation used a --env-info flag, but through review this
> was deemed to be not user friendly. I think the UX needs some discussion.
> 
> Addressing the concerns, can we not:
> 
>  $ juju switch [env]
>  $ juju info
>     # display env info of env user just switched into

OK, here is my proposal, which I hope addresses all the concerns and
gives us a way forwards.

 1) juju switch with no args becomes deprecated (replaced by juju info)
and will be removed one release following, continues to work as before
 2) juju switch --list becomes deprecated (replaced by juju info)
 3) juju switch <new-env> --format=[json,yaml] will output new
information, but just environment name, old env name and username
 4) juju env alias gets a deprecation warning (I'm sure we can work out
when a command is called through the alias), and next version we switch
the alias to be of 'info' not 'switch'
 5) add a juju info command that outputs:
    * environment name
    * uuid - if we have it
    * api end points
    * CACert - if we have it
    * status - [running, stopped, and soon maybe suspended]
    * username
   - supports json, yaml, and defaults to 'smart'
   - juju info becomes an environment command, so you can say
     juju info -e other-env
   - fields default to [environment-name, status, username]
   - all fields can be shown by using --all
 6) juju info --list will output the list of environments in either yaml
or json (or smart)

In all honesty, I should have done this originally.

Tim