I don't think I fully understand the proposal there. To have such a
"something-changed" hook, we ought to have a better mechanism to tell
*what* actually changed. In other words, we have a number of hooks
that imply a state transition or a specific notification ("install",
"start", "config-changed", "leader-elected" coming, etc). Simply
calling out the charm saying "stuff changed" feels like a bad
interface, both in performance terms (we *know* what changed) and in
user experience (how do people use that!?).I understand the underlying problem William is trying to solve but the current proposal doesn't seem like a complete solution on its own, and it also seems to change the existing understanding of the model completely. The proposed default-hooks is a trivial change to the existing well known workflow. On Sun, Aug 17, 2014 at 2:30 AM, John Meinel <[email protected]> wrote: > I'd just like to point out that William has thought long and hard about this > problem, and what semantics make the most sense (does it get called for any > hook, does it always get called, does it only get called when the hook > doesn't exist, etc). > I feel like had some really good decisions on it: > https://docs.google.com/a/canonical.com/document/d/1V5G6v6WgSoNupCYcRmkPrFKvbfTGjd4DCUZkyUIpLcs/edit# > > default-hook sounds (IMO) like it may run into problems where we do logic > based on whether a hook exists or not. There are hooks being designed like > leader-election and address-changed that might have side effects, and > default-hook should (probably?) not get called for those. > > I'd just like us to make sure that we actually think about (and document) > what hooks will fall into this, and make sure that it always makes sense to > rebuild the world on every possible hook (which is how charm writers will be > implementing default-hook, IMO). > > John > =:-> > > > > On Sat, Aug 16, 2014 at 1:02 AM, Aaron Bentley <[email protected]> > wrote: >> >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA1 >> >> On 14-08-15 04:36 PM, Nate Finch wrote: >> > There's new hook in town: default-hook. If it exists and a hook >> > gets called that doesn't have a corresponding hook file, >> > default-hook gets called with the name of the original hook as its >> > first argument (arg[1]). >> > >> > That's it. >> >> Nice! Thank you. >> >> Aaron >> -----BEGIN PGP SIGNATURE----- >> Version: GnuPG v1 >> >> iQEcBAEBAgAGBQJT7nVvAAoJEK84cMOcf+9h90UH/RMVabfJp4Ynkueh5XQiS6mD >> TPWwY0FVHfpAWEIbnQTQpnmkhMzSOKIFy0fkkXkEx4jSUt6I+iNYXdu8T77mA38G >> 7IZ7HAi+dAzRCrGTIZHsextrs5VpxhdzFJYOxL+TN5VUWYt+U+awSPFn0MlUZfAC >> 5aUuV3p3KjlHByLNT7ob3eMzR2mwylP+AS/9UgiojbUOahlff/9y83dYqkCDYzih >> C2rlwf0Wal12svu70ifggGKWcnF/eiwSm4TQjJsfMdCfw0gSg4ICgmIbWQ78OytJ >> AM4UBk1/Ue94dUm3YP+lcgAqJCC9GW5HksCFN74Qr+4xcnuqYoCJJxpU5fBOTls= >> =5YwW >> -----END PGP SIGNATURE----- >> >> -- >> Juju-dev mailing list >> [email protected] >> Modify settings or unsubscribe at: >> https://lists.ubuntu.com/mailman/listinfo/juju-dev > > > > -- > Juju-dev mailing list > [email protected] > Modify settings or unsubscribe at: > https://lists.ubuntu.com/mailman/listinfo/juju-dev > -- gustavo @ http://niemeyer.net -- Juju-dev mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/juju-dev
