support notification of releases to irc channel

[Khai Do]

It would be great if we could get notifications on irc when there is a project releases.

[Khai Do (zaro0508)]

I think the best trigger for generating this notification would be when a release tag is created in gerrit. We do have a release naming convention (https://wiki.openstack.org/wiki/Release_Naming) so that might be a good regex to determine if there is a release. IMO i think i would only want notifications for final releases, NOT for the alpha, beta, etc. releases. In terms of the notification message something like "Hot cakes, new release of Nova x.x.x" would be suffice.

[Ricardo Carrillo Cruz (rcarrillocruz)]

Need to deploy a vm with Git/Gerrit to test how it shows up a 'git tag blah' in the gerrit event streams.
Upon that, will look into gerritbot to match the event and post the message to the channel,

[Ricardo Carrillo Cruz (rcarrillocruz)]

Deployed a VM with gerrit/git.

If I run the following commands to create and push a tag to gerrit:

<snip>
git tag -a 2014.06.03 -m "March release"
git push gerrit 2014.06.03
</snip>

then gerrit events stream logs that action as:

<snip>
{"type":"ref-updated","submitter":{"name":"Ricardo Carrillo Cruz","email":"<email address hidden>","username":"rcarrillocruz"},"refUpdate":{"oldRev":"0000000000000000000000000000000000000000","newRev":"b3510fbe11adeba89abb03db451b83e86ba4abce","refName":"refs/tags/2014.06.03","project":"demo/gerrittest"}}
</snip>

So now it's a matter of adding a method to the Gerrit class in bot.py that handles the 'ref-updated' event and checks whether the 'refName' field to contain a release tag.

[James E. Blair (corvus)]

I think that looks about right. I think though that rather than trying to encode the rules for what is a release tag vs some other kind of tag (it's a REALLY long regex), we should just have the bot announce all tags. They are all interesting and rare enough that I think that will suit the purpose.

So just have it match "refs/tags/.*", and then announce something like "<username> tagged <project> with <tagname>".

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/79205
Committed: https://git.openstack.org/cgit/openstack-infra/gerritbot/commit/?id=575b062cbd46957d31dd21fa94bacd1d507dbbee
Submitter: Jenkins
Branch: master

commit 575b062cbd46957d31dd21fa94bacd1d507dbbee
Author: Ricardo Carrillo Cruz <email address hidden>
Date: Sun Mar 9 19:51:57 2014 +0000

    Add support for notification of releases on IRC

    Closes-Bug: #1227985

    Change-Id: I9b80b465d9d6b0e2793286cc8229b82b4389a08d