One-way communication in relation-get (was Re: Juju feedback from the Launchpad Yellow Squad)
kapil.thangavelu at canonical.com
Tue Feb 21 17:25:08 UTC 2012
Excerpts from Gary Poster's message of Wed Feb 15 14:43:43 -0500 2012:
> On 02/15/12 13:30, Graham Binns wrote:
> > * The one-way communication aspect of relation-set was surprising (so I
> > can relation-set foo=bar but I can never find out later on what I've
> > already told a relation about config options).
> > It would be great if there were a utility to retrieve whatever had
> > been sent to a relation. This would also be a nice way of caching
> > things for Charms :).
> hazmat pointed out on IRC that this is possible now, and that
> "relation-get -h" gives some direction on how. Putting "relation-get
> -h" and https://juju.ubuntu.com/docs/charm.html#hook-environment
> together, if you want to get the value for "mykey" that you set in a
> relation, you can use "relation-get mykey $JUJU_UNIT_NAME".
> hazmat continued, "it needs documentation, and it looks like it should
> be a switch so a key doesn't need to be specified."
fwiw, I found that the current implementation supports not passing an explicit
key via usage of '-' as the key name to get all key/values.
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