"snap info" should provide detailed track/channel release information.

[Daniel Manrique]

Snap info should show track information, if the snap is using tracks, under its channels section.

Current example:

$ snap info othersnap
name: othersnap
summary: "other-snap testing snap"
publisher: someone
description: |
  This is a test snap
channels:
  stable: 1.5 (4) 86kB -
  candidate: 1.5 (4) 86kB -
  beta: 1.5 (4) 86kB -
  edge: 1.5 (4) 86kB -

The design document suggests it should show information like this:

$ snap info othersnap
name: othersnap
summary: "Test snap"
publisher: someone
tracking: 2.1/stable
channels:
  - latest:
      stable: 3.1 (5) 0B -
      candidate: 3.1 (5) 0B -
      beta: 3.1 (5) 0B -
      edge: 3.1 (5) 0B -
  - 2.1:
      stable: 2.1 (1) 0B -
      candidate: 2.1 (1) 0B -
      beta: 2.3 (3) 0B -
      edge: 2.3 (3) 0B -

The detailed channel map list with track data can be obtained by asking for the channel_maps_list as a field when hitting the /details endpoint (if you don't ask for this info, it just will behave as before, so there's no compatibilities concern).

A real example from etcd, a snap that uses tracks:

$ curl -H 'x-ubuntu-series: 16' -H 'x-ubuntu-architecture: amd64' https://search.apps.ubuntu.com/api/v1/snaps/details/etcd?fields=name,revision,channel_maps_list | jq .

{
  "name": "etcd.canonical",
  "package_name": "etcd",
  "_links": {
    "curies": [
      {
        "href": "https://wiki.ubuntu.com/AppStore/Interfaces/ClickPackageIndex#reltype_{rel}",
        "name": "clickindex",
        "templated": true
      }
    ],
    "self": {
      "href": "https://search.apps.ubuntu.com/api/v1/snaps/details/etcd?fields=name,revision,channel_maps_list"
    }
  },
  "channel_maps_list": [
    {
      "track": "latest",
      "map": [
        {
          "info": "released",
          "version": "3.1.3",
          "binary_filesize": 7340032,
          "epoch": "0",
          "confinement": "strict",
          "channel": "stable",
          "revision": 41
        },
        {
          "info": null,
          "channel": "candidate"
        },
        {
          "info": null,
          "channel": "beta"
        },
        {
          "info": "released",
          "version": "3.1+master",
          "binary_filesize": 10715136,
          "epoch": "0",
          "confinement": "strict",
          "channel": "edge",
          "revision": 43
        }
      ]
    },
    {
      "track": "2.3",
      "map": [
        {
          "info": "released",
          "version": "2.3.8",
          "binary_filesize": 5795840,
          "epoch": "0",
          "confinement": "strict",
          "channel": "2.3/stable",
          "revision": 22
        },
        {
          "info": "released",
          "version": "2.3.8",
          "binary_filesize": 5795840,
          "epoch": "0",
          "confinement": "strict",
          "channel": "2.3/candidate",
          "revision": 39
        },
        {
          "info": null,
          "channel": "2.3/beta"
        },
        {
          "info": null,
          "channel": "2.3/edge"
        }
      ]
    },
    {
      "track": "3.0",
      "map": [
        {
          "info": "released",
          "version": "3.0.17",
          "binary_filesize": 7950336,
          "epoch": "0",
          "confinement": "strict",
          "channel": "3.0/stable",
          "revision": 24
        },
        {
          "info": "released",
          "version": "3.0.17",
          "binary_filesize": 7950336,
          "epoch": "0",
          "confinement": "strict",
          "channel": "3.0/candidate",
          "revision": 40
        },
        {
          "info": null,
          "channel": "3.0/beta"
        },
        {
          "info": null,
          "channel": "3.0/edge"
        }
      ]
    },
    {
      "track": "3.1",
      "map": [
        {
          "info": "released",
          "version": "3.1.3",
          "binary_filesize": 7340032,
          "epoch": "0",
          "confinement": "strict",
          "channel": "3.1/stable",
          "revision": 41
        },
        {
          "info": null,
          "channel": "3.1/candidate"
        },
        {
          "info": null,
          "channel": "3.1/beta"
        },
        {
          "info": "released",
          "version": "3.1+master",
          "binary_filesize": 10715136,
          "epoch": "0",
          "confinement": "strict",
          "channel": "3.1/edge",
          "revision": 43
        }
      ]
    },
    {
      "track": "ingest",
      "map": [
        {
          "info": "released",
          "version": "ingest-0.5",
          "binary_filesize": 4096,
          "epoch": "0",
          "confinement": "classic",
          "channel": "ingest/stable",
          "revision": 12
        },
        {
          "info": null,
          "channel": "ingest/candidate"
        },
        {
          "info": null,
          "channel": "ingest/beta"
        },
        {
          "info": null,
          "channel": "ingest/edge"
        }
      ]
    }
  ],
  "revision": 41
}

[Michael Vogt (mvo)]

Work has started, but some open questions needs to be resolved first, I started a discussion in https://forum.snapcraft.io/t/channels-2-0-implementation/156

[Facundo Batista (facundo)]

Thanks Michael!

Note that after we fixed a bug, we have channel_maps_list for hello-world again.