Add distro_python3 option

As we add support for python3 on RHEL based systems, we need to add a
flag to key off of in the Dockerfiles to swap out the python3 package
names.  This change adds a distro_python3 configuration option that can
be defined to force python3 or python2 package names.  If this option
is not provided, we set this to True for RHEL 8 based distros and false
for other distros.

Change-Id: I4028991bad92c0e8e21066cc4173c06ce5eba393
Related-Blueprint: python3-support

kolla/common/config.py

@@ -266,6 +266,10 @@ _BASE_OPTS = [
     cfg.StrOpt('maintainer',
                default='Kolla Project (https://launchpad.net/kolla)',
                help='Content of the maintainer label'),
+    cfg.BoolOpt('distro_python3', default=None,
+                help=('Enable this to force python3 packaging names. By '
+                      'default this will try and determine the value of this '
+                      'based on the base_distro and base_distro_tag.')),
     cfg.ListOpt('rpm_setup_config', default=[DELOREAN, DELOREAN_DEPS],
                 help=('Comma separated list of .rpm or .repo file(s) '
                       'or URL(s) to install before building containers')),

kolla/image/build.py

@@ -689,6 +689,14 @@ class KollaWorker(object):
         deb_base = ['ubuntu', 'debian']
         deb_type = ['source', 'binary']
 
+        if self.conf.distro_python3 is not None:
+            self.distro_python3 = self.conf.distro_python3
+        elif self.base in rh_base and self.base_tag in ['8']:
+            # RHEL 8+ is python3
+            self.distro_python3 = True
+        else:
+            self.distro_python3 = False
+
         if not ((self.base in rh_base and self.install_type in rh_type) or
                 (self.base in deb_base and self.install_type in deb_type)):
             raise exception.KollaMismatchBaseTypeException(
@@ -888,6 +896,7 @@ class KollaWorker(object):
                       'kolla_version': kolla_version,
                       'image_name': image_name,
                       'users': self.get_users(),
+                      'distro_python3': self.distro_python3,
                       'rpm_setup': self.rpm_setup,
                       'build_date': build_date}
             env = jinja2.Environment(  # nosec: not used to render HTML

kolla/tests/test_build.py

@@ -381,6 +381,26 @@ class KollaWorkerTest(base.TestCase):
         kolla = build.KollaWorker(self.conf)
         self.assertEqual(2, len(kolla.rpm_setup))
 
+    def test_build_distro_python3(self):
+        """check distro_python3 conf value is taken"""
+        self.conf.set_override('distro_python3', True)
+        kolla = build.KollaWorker(self.conf)
+        self.assertTrue(kolla.distro_python3)
+
+    def test_build_distro_python3_rhel8(self):
+        """check distro_python3 true for rhel8"""
+        self.conf.set_override('base', 'rhel')
+        self.conf.set_override('base_tag', '8')
+        kolla = build.KollaWorker(self.conf)
+        self.assertTrue(kolla.distro_python3)
+
+    def test_build_distro_python3_non_rhel8(self):
+        """check distro_python3 false for non-rhel8"""
+        self.conf.set_override('base', 'rhel')
+        self.conf.set_override('base_tag', '7')
+        kolla = build.KollaWorker(self.conf)
+        self.assertFalse(kolla.distro_python3)
+
     def test_pre_defined_exist_profile(self):
         # default profile include the fake image: image-base
         self.conf.set_override('profile', ['default'])

releasenotes/notes/distro-python3-configuration-3ed58b21b0f43246.yaml

@@ -0,0 +1,8 @@
+---
+features:
+  - |
+    Added a `distro_python3` configuration option for the kolla-build.conf
+    that will switch the package names to assume the python3 name. By default,
+    this will be True if a RHEL 8 based distro and False for any other distro.
+    If a value of True or False is provided in the configuration, this will
+    override the derived value.