Move pot file generation to venv

periodic job failed since some weeks due the usage of Sphinx 2.0
in Python 2.7, called by the shell script outside venv

see:
http://logs.openstack.org/periodic/opendev.org/openstack/training-guides/master/propose-translation-update/a09c131/

Maybe get job working again after some weeks.
Requires still a general patch for propose-translation-update to run
on Bionic with Sphinx 2 and Python 3.

Change-Id: I40a271bdc171ee7dc433178633c190c7bd1e8e5f

tools/generatepot-training.sh

@@ -1,47 +0,0 @@
-#!/bin/bash -xe
-
-#
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-
-DOCNAME=upstream-training
-DIRECTORY=doc/${DOCNAME}
-
-if [ -x "$(command -v getconf)" ]; then
-    NUMBER_OF_CORES=$(getconf _NPROCESSORS_ONLN)
-else
-    NUMBER_OF_CORES=2
-fi
-
-# First remove the old pot file, otherwise the new file will contain
-# old references
-
-rm -f ${DIRECTORY}/source/locale/$DOCNAME.pot
-
-# upstream-training contains the HTML and slides contents
-
-# build upstream-training slides
-sphinx-build -j $NUMBER_OF_CORES -b gettext ${DIRECTORY}/source/slides \
-    ${DIRECTORY}/source/locale/
-# build upstream landing page index.html
-sphinx-build -j $NUMBER_OF_CORES -b gettext ${DIRECTORY}/source/website \
-    ${DIRECTORY}/source/locale/
-
-# Take care of deleting all temporary files so that
-# "git add ${DIRECTORY}/source/locale" will only add the
-# single pot file.
-# Remove UUIDs, those are not necessary and change too often
-msgcat --use-first --sort-by-file ${DIRECTORY}/source/locale/*.pot | \
-    awk '$0 !~ /^\# [a-z0-9]+$/' > ${DIRECTORY}/source/$DOCNAME.pot
-rm  ${DIRECTORY}/source/locale/*.pot
-rm -rf ${DIRECTORY}/source/locale/.doctrees/
-mv ${DIRECTORY}/source/$DOCNAME.pot ${DIRECTORY}/source/locale/$DOCNAME.pot

tox.ini

@@ -14,9 +14,11 @@ whitelist_externals =
   mkdir
   rm
   rsync
+  msgcat
+  awk
+  bash
 
 [testenv:venv]
-basepython = python3
 commands = {posargs}
 
 [doc8]
@@ -35,6 +37,20 @@ commands =
   rsync -av doc/upstream-training/build/slides/ publish-docs/upstream-training/
   rsync -av doc/training-guides/build/slides/ publish-docs/training-guides/
 
+[testenv:generatepot-training]
+# Generate POT files for translation
+commands =
+  rm -f doc/upstream-training/source/locale/upstream-training.pot
+  sphinx-build -b gettext doc/upstream-training/source/slides \
+    doc/upstream-training/source/locale/
+  sphinx-build -b gettext doc/upstream-training/source/website \
+    doc/upstream-training/source/locale/
+  bash -c "msgcat --use-first --sort-by-file doc/upstream-training/source/locale/*.pot | \
+    awk '$0 !~ /^\# [a-z0-9]+$/' > doc/upstream-training/source/upstream-training.pot && \
+    rm doc/upstream-training/source/locale/*.pot && \
+    rm -rf doc/upstream-training/source/locale/.doctrees/ && \
+    mv doc/upstream-training/source/upstream-training.pot doc/upstream-training/source/locale/upstream-training.pot"
+
 [testenv:publishdocs]
 passenv = ZUUL*
 commands =
@@ -72,7 +88,3 @@ commands =
   sphinx-build -W -b slides -d doc/training-guides/build/slides.doctrees/associate-guide doc/training-guides/source/slides doc/training-guides/build/slides/associate-guide
   # Build training-guides landing page index.html
   sphinx-build -b html -d doc/training-guides/build/slides.doctrees doc/training-guides/source/website doc/training-guides/build/slides
-
-[testenv:generatepot-training]
-# Generate POT files for translation
-commands = {toxinidir}/tools/generatepot-training.sh