Important - proposed Juju plugin change

[Marco Ceppi]

It's easy enough to add a small parser and check for the environment
variables. FWIW, I think this would really streamline the user experience
when using these plugins.


On Wed, Jul 31, 2013 at 9:40 PM, Ian Booth <ian.booth at canonical.com> wrote:

> Don't change anything yet!
> At this stage it's just up for discussion :-)
>
> On Thu 01 Aug 2013 11:38:39 EST, Marco Ceppi wrote:
> > +1 from me, I'll make the change in the only plugin to reflect this.
> Thanks
> > for the heads up!
> >
> >
> > On Wed, Jul 31, 2013 at 9:34 PM, Mark Mims <mark.mims at canonical.com>
> wrote:
> >
> >> +1... ok with plugins parsimg everything they need and/or taking
> >> responsibility to pass them along to actual subcommands.
> >>
> >> -- (mobile)
> >> Mark Mims, Ph.D.
> >> Ubuntu Server Team
> >> Canonical Ltd
> >> mark.mims at canonical.com
> >> +1(512)981-6467
> >>
> >> On Jul 31, 2013, at 15:27, Ian Booth <ian.booth at canonical.com> wrote:
> >>
> >>> Sending to you guys directly as well....
> >>>
> >>>
> >>> -------- Original Message --------
> >>> Subject: Important - proposed Juju plugin change
> >>> Date: Thu, 01 Aug 2013 11:19:16 +1000
> >>> From: Ian Booth <ian.booth at canonical.com>
> >>> To: juju-dev at lists.ubuntu.com <Juju-dev at lists.ubuntu.com>
> >>>
> >>> Hi folks
> >>>
> >>> Juju processes arguments used when calling a plugin, acting on common
> >> things;
> >>> the main one is using -e to set the environment. However, this means
> >> plugins
> >>> require the use of "--" to receive any additional arguments. eg
> >>>
> >>> juju myplugin -e myenv -- -pluginarg
> >>>
> >>> The above would set JUJU_ENV to myenv and pass -pluginarg to the
> plugin.
> >>>
> >>> This is kinda conceptually messy for the end user, having to know to
> use
> >> "--".
> >>> And it's now made worse by the fact that the new simplestreams tools
> >> plugins
> >>> which ship with Juju do not require "--" since they are built on top of
> >> Juju
> >>> command infrastructure. So this works:
> >>>
> >>> juju metadata validate-images -e myenv -s raring
> >>>
> >>> If it were an "external" plugin, it would need to be:
> >>>
> >>> juju metadata validate-images -e myenv -- -s raring
> >>>
> >>> What we are proposing is to drop the "--". However, this means that:
> >>>
> >>> - plugins are responsible for processing *all* of their own arguments
> >>> - common Juju arguments like "-e" are no longer automatically processed
> >>>
> >>> So if a plugin is called with "-e myenv", it will need to parse the -e
> >> itself
> >>> and set JUJU_ENV and not count on it being done by Juju. Or course, if
> >> the
> >>> plugin is written in Go, it can always use the built in parsing just
> >> like the
> >>> simplestreams metadata plugin does.
> >>>
> >>> Can I please have feedback from anyone who has written a Juju plugin
> who
> >> would
> >>> find the above change problematic? Users of plugins would just need to
> >> tweak any
> >>> scripts which call them to remove the "--".
> >>>
> >>>
> >>>
> >>> --
> >>> Juju-dev mailing list
> >>> Juju-dev at lists.ubuntu.com
> >>> Modify settings or unsubscribe at:
> >>> https://lists.ubuntu.com/mailman/listinfo/juju-dev
> >>>
> >>>
> >>
> >
>
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