Add Support for validating 4 digit verion strings

The xstatic packages have a 4 digit verion number 3-digit semver as
supplied by upstream and a local build number.  PBR only supports 3
digit semver.

To work with that create the concpet of a release type that can have
slightly different validation rules.  In this case use the 'packaging'
library.

This will allow the horizon team to use the standard release process.

For refernce see:
https://blueprints.launchpad.net/horizon/+spec/xstatic-release-process

Change-Id: Ie0f33097c31ee4006ec58147b35731913f7b6f4b

README.rst

@@ -232,6 +232,18 @@ The top level of a deliverable file is a mapping with keys:
       This repository is no longer used, but was present in old
       versions of a deliverable.
 
+``release-type``
+  This (optional) key sets the level of validation for the versions numbers.
+
+  ``std``
+      Default: Enforces 3 digit semver version numbers in releases and allows
+      for common alpha, beta and dev releases.  This should be appropriate for
+      most OpenStack release requirements.
+
+  ``xstatic``
+      Allows a more flexible versioning in line with xstatic package guidelines
+      and requirements.
+
 ``releases``
   A list of the releases for the deliverable.
 

openstack_releases/cmds/validate.py

@@ -129,6 +129,9 @@ def main():
             warnings.append('Team %r in %s not in governance data' %
                             (deliverable_info['team'], filename))
 
+        # Look for the release-type
+        release_type = deliverable_info.get('release-type', 'std')
+
         # Look for an email address to receive release announcements
         try:
             announce_to = deliverable_info['send-announcements-to']
@@ -262,7 +265,8 @@ def main():
                         else:
 
                             for e in versionutils.validate_version(
-                                    release['version']):
+                                    release['version'],
+                                    release_type=release_type):
                                 msg = ('could not validate version %r '
                                        'for %s: %s' %
                                        (release['version'], filename, e))

openstack_releases/versionutils.py

@@ -14,23 +14,45 @@
 
 from __future__ import unicode_literals
 
+import packaging.version
 import pbr.version
 
+# The keys for this dict are the valid release types for OpenStack releases.
+# The values are a three-tuple that contains:
+#  1. constructor:  The function used to convert the version string in to a
+#                   *Verion object.
+#  2. exception:    The excpetion raised by the constructor iff version string is invalid
+#                   in some way.
+#  3. canonicalise: The function used to canonicalise the *Version object.
+#                   Used to verify that the version string is already in the
+#                   canonical form
+_VALIDATORS = {'std': (pbr.version.SemanticVersion.from_pip_string,
+                       ValueError,
+                       lambda x: x.release_string()),
+               'xstatic': (packaging.version.Version,
+                           packaging.version.InvalidVersion,
+                           lambda x: str(x)),
+               }
 
-def validate_version(versionstr):
+
+def validate_version(versionstr, release_type='std'):
     """Given a version string, yield error messages if it is "bad"
 
     Apply our SemVer rules to version strings and report all issues.
 
     """
-    # Apply pbr rules
+    if release_type not in _VALIDATORS:
+        yield 'Release Type %s not valid using \'std\'' % release_type
+        release_type = 'std'
+
+    constructor, exception, canonicalise = _VALIDATORS[release_type]
     try:
-        semver = pbr.version.SemanticVersion.from_pip_string(versionstr)
-    except ValueError as err:
+        semver = constructor(versionstr)
+    except exception as err:
         yield 'Invalid version: %s' % err
     else:
-        # Make sure pbr didn't change the version to meet the canonical form.
-        canonical = semver.release_string()
+        # Make sure we didn't change the version to meet the canonical form.
+        canonical = canonicalise(semver)
         if canonical != versionstr:
             yield 'Version %r does not match canonical form %r' % \
                 (versionstr, canonical)

requirements.txt

@@ -6,3 +6,4 @@ zuul
 yamlordereddictloader
 prompt_toolkit
 tqdm
+packaging>=15.2