-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2015-04-29 04:10 AM, roger peppe wrote: > On 28 April 2015 at 19:32, Aaron Bentley > <aaron.bent...@canonical.com> wrote: >> On 2015-04-28 11:42 AM, roger peppe wrote: >>> The .jenv code was introduced prior to 1.16. How far back in >>> time do we need to preserve compatibility? (genuine question) >> >> We need to support every mode of operation that 1.18 supported. >> Juju has a special exemption that allows minor releases, rather >> than micro/bugfix releases, to added to Ubuntu. But in order to >> use that exemption, new versions of Juju are supposed to be >> equivalent to a micro/bugfix release in terms of their >> compatibility. > > So in general version 1.n will need to support every mode of > operation that version 1.n-1 supports? By induction doesn't that > mean we can never remove any features at all ever from Juju, > because every version will need to support every mode of operation > supported by *all* previous versions?
No, only as long as 1.18 is in a supported release, i.e. until Trusty EOL. But as William said, "I tend to abbreviate this in casual conversation as "forever"" Once Trusty EOLs, then I think we would be able to drop functionality that 1.18 itself used only for migration. For example, if juju 1.18 had automatically created .jenvs from the environments.yaml instead of using environments.yaml directly, then when Trusty EOLed, we could drop that functionality. The other thing is that Juju 2.0 will not have this requirement. >> We had our own IS people upgrade to juju 1.20 from 1.18 and find >> that juju no longer worked. That's terrible. > > Would it have been so terrible if the release notes had said "to > upgrade to juju 1.20, run this tool to transition your existing > local environment store first"? Yes. People can upgrade from 1.18.4 to 1.20.11 using apt-get just by having the trusty-updates repository enabled. They are not supposed to have to read release notes-- trusty-updates is supposed to be non-breaking changes. Aaron -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJVQN35AAoJEK84cMOcf+9hs8cH+gMNGV4Glnp2gfqdomKPlzGd q92ukPLFFw8LL745OjGczn4Cy0BKqLT8kafMINKptx17MiC+vEHbuxnTNoHfrMKQ vqlUqzb7lwZMEc6s9j0iguFGJ/IjpF0tUeYOIZQst6lwPKlqUlA6KXhkCcvg3mh0 IpBkCQDlkSUfgP8xLZLdIq0OyZls6WPBsrZmywT0+rfnimMNlJSc82gIs8HFmnfN blisw8Y721VywJyja+gvhhPM9ylwi4SvAaJ/s9+yVk8bEUmQe3YM567+LVqrf2Hz v3s46q5597BR0ECddUCIQYxATtDkSeU45RwdawHAHChosdJwXIVGGoSt9Ner5B4= =B7QT -----END PGP SIGNATURE----- -- Juju-dev mailing list Juju-dev@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/juju-dev
