Merge ~paride/ubuntu-release-tools/+git/templates:snap-channel-opening-howto into ~ubuntu-release/ubuntu-release-tools/+git/templates:main

[Paride Legovini]

Add steps on how to verify that snap stable channels are open

[Brian Murray (brian-murray)]

There is a second description in here which looks incomplete, could you sort that out? Additionally, I have an in-line comment about how to find image owners.

[Paride Legovini (paride)]

I didn't know that, thanks! MP updated.

diff --git a/jira-milestones/new-cycle-opening.yaml b/jira-milestones/new-cycle-opening.yaml
index 53dc493..57553a0 100644
--- a/jira-milestones/new-cycle-opening.yaml
+++ b/jira-milestones/new-cycle-opening.yaml
@@ -114,6 +114,15 @@
   - task: Inform the SRU team that the bulk copy has been done, so that they know to sort out PREVIOUS-proposed vs. DEVEL-proposed for any new SRUs they accept
   - task: Drop the --dry-run flag from the auto-sync job in ubuntu-archive@snakefruit's crontab
   - task: Contact owners of each image with seeded snaps to have snap channels opened and closed for the new release
+    description: |
+      Note: image owners are listed in the product manifests available from the ISO Tracker (https://iso.qa.ubuntu.com/).
+    checklist:
+    - Get the list of seeded snaps from the seeds: `readarray -t seeded_snaps < <(grep -ohP '(?<=snap:)[^\s/]*' * 2>/dev/null | sort -u)`
+    - Add subiquity as it's seeded but not in the seeds: `seeded_snaps+=(subiquity)`
+    - Try downloading all the snaps from the stable channel: for `s in "${seeded_snaps[@]}"; do snap download "$s" --channel=stable/ubuntu-XX.YY; done`
+    - If a failing download is for an internally developed snap (we're upstream), contact the relevant team to have the channel open.
+    - If a failing download is for an external snap (e.g. firefox), ask the image owner to ask the snap upstream to open the channel.
+    - Iterate until all the downloads succeed.
   - task: "Create new live filesystem configurations for the new distroseries, using branch-livefses in lp:ubuntu-archive-tools"
     description: <
       This requires someone in ~launchpad-ppa-admins/~launchpad-ppa-self-admins, ~ubuntu-cdimage and ~launchpad-livefs-builders.