Charmhub compatibility references incorrect stable channel for bundles

[Adam Dyess]

Lookups through the charmhub compatibility API seem to be resolving requests without a channel to the wrong stable channel:

Current Revisions & Channels:

---------------------------------------------
❯ charmcraft status charmed-kubernetes
Track Base Channel Version Revision
latest - stable 1020 1020
                 candidate 814 814
                 beta 1006 1006
                 edge 1026 1026
1.23 - stable - -
                 candidate - -
                 beta - -
                 edge 942 942
1.24 - stable 1021 1021
                 candidate ↑ ↑
                 beta 1005 1005
                 edge 1027 1027

# With a stable channel, the referenced bundle is latest/stable 1020
❯ curl 'https://api.jujucharms.com/charmstore/v5/charmed-kubernetes/meta/any?channel=stable'
{"Id":"cs:bundle/charmed-kubernetes-1020"}

# With a candidate channel, the referenced bundle is latest/candidate 814
❯ curl 'https://api.jujucharms.com/charmstore/v5/charmed-kubernetes/meta/any?channel=candidate'
{"Id":"cs:bundle/charmed-kubernetes-814"}

# With a beta channel, the referenced bundle is latest/beta 1006
❯ curl 'https://api.jujucharms.com/charmstore/v5/charmed-kubernetes/meta/any?channel=beta'
{"Id":"cs:bundle/charmed-kubernetes-1006"}

# With a edge channel, the referenced bundle is latest/edge 1026
❯ curl 'https://api.jujucharms.com/charmstore/v5/charmed-kubernetes/meta/any?channel=edge'
{"Id":"cs:bundle/charmed-kubernetes-1026"}

# Without a channel, the bundle resolved is 1.24/stable 1021
❯ curl 'https://api.jujucharms.com/charmstore/v5/charmed-kubernetes/meta/any'
{"Id":"cs:bundle/charmed-kubernetes-1021"}

---------------------------------------------

1021 - this bundle isn't the latest/stable bundle -- the expected bundle according to
1021 - this bundle isn't even the edgiest of bundles like 1026
1021 seems to be the most recently published bundle with a risk stable, but that doesn't mean it's the latest/stable

I believe the latest/stable channel should be referenced when the channel isn't provided by the compatibility api according to the charmstore docs https://github.com/juju/charmstore/blob/v5/docs/API.md#channels

[Guillermo Gonzalez (verterok)]

Thanks for reporting this problem.

I can confirm this is a filtering related bug on the compatibility API which is using the most recent released revision by only filtering by risk and not taking track into account.

[Adam Dyess (addyess)]

Yep! Awesome. Works like a champ! Thanks so much