Allow to tag projects as "last" on EM branches

For testing for Extended Maintenance branches with branchless
Tempest and Tempest plugins, we need to release the new tag
for Tempest and its plugins as last compatible version for that
Extended Maintenance branches.

This commits adds the documentation and validation machinery changes about
that tag $series-last which will be used for branchless testing tooling.

Change-Id: I799e8e637a54a46fd7ca74dd568ea2c7506fa32d
Depends-On: https://review.opendev.org/c/openstack/project-team-guide/+/769821

doc/source/index.rst

@@ -55,9 +55,9 @@ updates.
 
 .. note::
    If a branch is marked as Extended Maintenance, that means individual
-   projects can be in state *Maintained*, *Unmaintained* or *End of Life* on
-   that branch. Please check specific project about its actual status on the
-   given branch.
+   projects can be in state *Maintained*, *Unmaintained*, *Last* or
+   *End of Life* on that branch. Please check specific project about its
+   actual status on the given branch.
 
 .. _Maintenance phases: https://docs.openstack.org/project-team-guide/stable-branches.html#maintenance-phases
 .. _old phases: https://github.com/openstack/project-team-guide/blob/1c837bf0~/doc/source/stable-branches.rst

openstack_releases/cmds/validate.py

@@ -1102,6 +1102,24 @@ def validate_version_numbers(deliv, context):
                         release.version, deliv.series))
             continue
 
+        if release.is_last:
+            LOG.debug('Found new LAST tag {} for {}'.format(
+                release.version, deliv.name))
+            if deliv.is_independent:
+                context.warning(
+                    'LAST tag {} on independent deliverable, branch not validated'.format(
+                        release.version))
+                continue
+            if release.version != "{}-last".format(deliv.series):
+                context.error(
+                    "LAST tag {} should match branch name (e.g {}-last)".format(
+                        release.version, deliv.series))
+            if not deliv.series_info.is_em:
+                context.error(
+                    "LAST tag {} aren't allowed on a series ({}) that are not EM".format(
+                        release.version, deliv.series))
+            continue
+
         for project in release.projects:
 
             if not gitutils.checkout_ref(context.workdir, project.repo.name,
@@ -1303,6 +1321,9 @@ def validate_new_releases_in_open_series(deliv, context):
             elif release.is_em:
                 LOG.debug('Found new EM tag {} for {}'.format(
                     release.version, project.repo))
+            elif release.is_last:
+                LOG.debug('Found new LAST tag {} for {}'.format(
+                    release.version, project.repo))
             else:
                 LOG.debug('Found new version {} for {}'.format(
                     release.version, project.repo))

openstack_releases/deliverable.py

@@ -64,7 +64,9 @@ def _version_sort_key(release):
     # won't have more than 1000 major releases of anything, and I
     # surely hope that is a safe assumption.
     version_string = release['version']
-    if version_string.endswith('-eol') or version_string.endswith('-em'):
+    if version_string.endswith('-eol') or \
+        version_string.endswith('-em') or \
+        version_string.endswith('-last'):
         return _safe_semver('1000.0.0')
     return _safe_semver(version_string)
 
@@ -338,6 +340,10 @@ class Release(object):
     def is_em(self):
         return self.version.endswith('-em')
 
+    @property
+    def is_last(self):
+        return self.version.endswith('-last')
+
     @property
     def em_series(self):
         if self.is_em: