add GH action for sending notifications of release status / reminders about milestone cleanup

[nickboldt]

What does this PR do?

add GH action for sending mail to che-dev list

Change-Id: I9fb886002932b68f8af72d1389c44f11901a09c6
Signed-off-by: nickboldt [email protected]

Screenshot/screencast of this PR

N/A

What issues does this PR fix or reference?

• When Che 7.y.0 releases are done, send reminder to TLs to clean milestones of any outstanding unresolved issues che#17579
• Improve Che Release Process Part 3 che#17748

How to test this PR?

N/A

PR Checklist

As the author of this Pull Request I made sure that:

• The Eclipse Contributor Agreement is valid
• Code produced is complete
• Code builds without errors
• Tests are covering the bugfix
• The repository devfile is up to date and works, if one exists
• Sections What issues does this PR fix or reference and How to test this PR completed
• Relevant user documentation updated
• Relevant contributing documentation updated
• CI/CD changes implemented, documented and communicated

Reviewers

Reviewers, please comment how you tested the PR when approving it.

[nickboldt]

If this doesn't work, we could try using a simple bash script, assuming mail or mailx is installed:

echo "...... email body here ...... " > mailbody.tmp
if [[ -x /bin/mailx ]]; then 
    /bin/mailx -s "''' + mailSubject + '''" -c "''' + CCrecipients + '''" -r "''' + sender + '''" "''' + TOrecipients + '''" < mailbody.tmp
else 
    /bin/mail -s "''' + mailSubject + '''" "''' + TOrecipients + '''" -c"''' + CCrecipients + '''" -- -f"''' + sender + '''" < mailbody.tmp
fi
rm -f mailbody.tmp

see full example in https://github.com/redhat-developer/codeready-workspaces/blob/crw-2.6-rhel-8/dependencies/send-email-qe-build-list.Jenkinsfile#L67-L76

[mkuznyetsov]

looks like it's gonna be on hold, until we will find appropriate smtp username&password

[mkuznyetsov]

need smtp username & password that can be used on "CI"

[nickboldt]

what about a mattermost post instead? https://github.com/marketplace/actions/mattermost (it's an official action from MM, not a random one from some user on the marketplace)

we could post to https://mattermost.eclipse.org/eclipse/channels/eclipse-che-releases

[nickboldt]

MM notification done in eclipse-che/che#18906