replace 'distro_python3' variable with 'distro_python_version'

RHEL7 derived distros use Python 2.7
RHEL8 uses Python 3.6
Ubuntu 18.04 uses Python 3.6, but we haven't enabled it yet.
Debian:buster uses Python 3.7, but we haven't enabled it yet.

We have several places in code where "/lib/pythonX.Y/site-packages"
is used so we need to know value of X.Y rather than py2/py3 switch.

How to check for Python 2:

{% if distro_python_version == '2.7' %}

Breaks: Iad6b70b433a0dd1b0f8ae6790fd280594517661a
Change-Id: Ie24f109af19ae0438c21e0d43cb3cc947812b4ce

6 files changed, 22 insertions, 10 deletions

diff --git a/docker/base/Dockerfile.j2 b/docker/base/Dockerfile.j2
index bd75f6a90..98e8ff132 100644
--- a/docker/base/Dockerfile.j2
+++ b/docker/base/Dockerfile.j2
@@ -17,7 +17,8 @@ LABEL kolla_version="{{ kolla_version }}"
 
 ENV KOLLA_BASE_DISTRO={{ base_distro }} \
     KOLLA_INSTALL_TYPE={{ install_type }} \
-    KOLLA_INSTALL_METATYPE={{ install_metatype }}
+    KOLLA_INSTALL_METATYPE={{ install_metatype }} \
+    KOLLA_DISTRO_PYTHON_VERSION={{ distro_python_version }}
 
 #### Customize PS1 to be used with bash shell
 COPY kolla_bashrc /tmp/
diff --git a/docker/horizon/Dockerfile.j2 b/docker/horizon/Dockerfile.j2
index 0fbeb39db..f2f341202 100644
--- a/docker/horizon/Dockerfile.j2
+++ b/docker/horizon/Dockerfile.j2
@@ -74,7 +74,7 @@ RUN echo > /etc/apache2/ports.conf \
     && cp /usr/share/openstack-dashboard/openstack_dashboard/conf/*.json /etc/openstack-dashboard \
     && cp /usr/share/openstack-dashboard/manage.py /usr/bin/manage.py \
     && rm /etc/apache2/conf-enabled/openstack-dashboard.conf \
-    && for locale in /usr/lib/python2.7/site-packages/*/locale; do \
+    && for locale in /usr/lib/python{{distro_python_version}}/site-packages/*/locale; do \
            (cd ${locale%/*} && /usr/bin/python /usr/bin/manage.py compilemessages) \
        done
 {% endblock %}
@@ -136,10 +136,10 @@ RUN ln -s horizon-source/* horizon \
     && if [ "$(ls /plugins)" ]; then \
            {{ macros.install_pip(horizon_plugins_pip_packages) }}; \
        fi \
-    && for locale in  /var/lib/kolla/venv/lib/python2.7/site-packages/*/locale; do \
+    && for locale in  /var/lib/kolla/venv/lib/python{{distro_python_version}}/site-packages/*/locale; do \
            (cd ${locale%/*} && /var/lib/kolla/venv/bin/python /var/lib/kolla/venv/bin/manage.py compilemessages) \
        done \
-    && chown -R horizon: /etc/openstack-dashboard /var/lib/kolla/venv/lib/python2.7/site-packages/static
+    && chown -R horizon: /etc/openstack-dashboard /var/lib/kolla/venv/lib/python{{distro_python_version}}/site-packages/static
 
 {% endif %}
 
diff --git a/docker/horizon/extend_start.sh b/docker/horizon/extend_start.sh
index 8a3227166..1dc6aeb60 100644
--- a/docker/horizon/extend_start.sh
+++ b/docker/horizon/extend_start.sh
@@ -5,9 +5,9 @@ set -o errexit
 FORCE_GENERATE="${FORCE_GENERATE}"
 
 if [[ ${KOLLA_INSTALL_TYPE} == "binary" ]]; then
-    SITE_PACKAGES="/usr/lib/python2.7/site-packages"
+    SITE_PACKAGES="/usr/lib/python${KOLLA_DISTRO_PYTHON_VERSION}/site-packages"
 elif [[ ${KOLLA_INSTALL_TYPE} == "source" ]]; then
-    SITE_PACKAGES="/var/lib/kolla/venv/lib/python2.7/site-packages"
+    SITE_PACKAGES="/var/lib/kolla/venv/lib/python${KOLLA_DISTRO_PYTHON_VERSION}/site-packages"
 fi
 
 if [[ ${KOLLA_INSTALL_TYPE} == "source" ]] && [[ ! -f ${SITE_PACKAGES}/openstack_dashboard/local/local_settings.py ]]; then
diff --git a/docker/kolla-toolbox/Dockerfile.j2 b/docker/kolla-toolbox/Dockerfile.j2
index ca616074b..4af30dede 100644
--- a/docker/kolla-toolbox/Dockerfile.j2
+++ b/docker/kolla-toolbox/Dockerfile.j2
@@ -4,7 +4,7 @@ LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build
 {% block kolla_toolbox_header %}{% endblock %}
 
 {% set virtualenv_path='/opt/ansible' %}
-{% set os_client_config= virtualenv_path + '/lib/python2.7/site-packages/os_client_config/defaults.json' %}
+{% set os_client_config= virtualenv_path + '/lib/python' + distro_python_version + '/site-packages/os_client_config/defaults.json' %}
 
 {% import "macros.j2" as macros with context %}
 
diff --git a/docker/macros.j2 b/docker/macros.j2
index aee933e7b..419fa0f4f 100644
--- a/docker/macros.j2
+++ b/docker/macros.j2
@@ -22,8 +22,13 @@
 {%- endmacro %}
 
 {% macro get_pip() %}
+{% if distro_python_version == '2.7' %}
+    {% set python='python' %}
+{% else %}
+    {% set python='python3' %}
+{% endif %}
 RUN curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py \
-    && python get-pip.py \
+    && {{python}} get-pip.py \
     && rm get-pip.py
 {% endmacro %}
 
diff --git a/docker/openstack-base/Dockerfile.j2 b/docker/openstack-base/Dockerfile.j2
index c3dab166a..4f6627197 100644
--- a/docker/openstack-base/Dockerfile.j2
+++ b/docker/openstack-base/Dockerfile.j2
@@ -211,11 +211,9 @@ ENV DEBIAN_FRONTEND noninteractive
         'debtcollector',
         'decorator',
         'elasticsearch',
-        'enum34',
         'eventlet',
         'fasteners',
         'funcsigs',
-        'functools32',
         'futures',
         'futurist',
         'gnocchiclient',
@@ -297,6 +295,14 @@ ENV DEBIAN_FRONTEND noninteractive
     ]
 %}
 
+{% if distro_python_version == '2.7' %}
+    {% set openstack_base_pip_packages = openstack_base_pip_packages + [
+             'enum34',
+             'functools32'
+         ]
+    %}
+{% endif %}
+
 ADD openstack-base-archive /openstack-base-source
 RUN ln -s openstack-base-source/* /requirements \
     && mkdir -p /var/lib/kolla \