Change check_uptodate.sh to not call tox

Base nodepool images now no longer include tox. This causes a failure in
our pep8 jobs because the tools/config/check_uptodate.sh script had been
calling "tox -e genopts" to look for config file changes.

This is a partial backport of a change that switched our default
basepython to python3. That part of the change was removed from tox.ini,
so the only other part was an update to the check_uptodate.sh script
that refactored things to be more reliable, including the removal of
calling tox.

The part from the original commit included is:

There was also a difference in behavior with the genopts job
where it ends up trying to recreate the venv under which it
is currently running under, resulting in a corrupted venv
and a failure. This cleans up that script and changes it so
rather than a tox job calling a tox job it just runs the
script.

Change-Id: Ie79528b33070e6c60f9f5e1f2219084a2f0cb039
(cherry picked from commit 37510ac034)

tools/config/check_uptodate.sh

@@ -1,35 +1,55 @@
 #!/usr/bin/env bash
 
+#    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.
+
+# This script is used to check if there have been configuration changes that
+# have not been checked in.
+
+# The opts file needs to be present in order to compare it
 if [ ! -e cinder/opts.py ]; then
-    echo -en "\n\n#################################################"
-    echo -en "\nERROR: cinder/opts.py file is missing."
-    echo -en "\n#################################################\n"
+    echo ""
+    echo "#################################################"
+    echo "ERROR: cinder/opts.py file is missing."
+    echo "#################################################"
+    exit 1
+fi
+
+# Rename the existing file so we can generate a new one to compare
+mv cinder/opts.py cinder/opts.py.orig
+python tools/config/generate_cinder_opts.py &> tox-genops.log
+if [ $? -ne 0 ]; then
+    cat tox-genops.log >&2
+    echo ""
+    echo "#################################################"
+    echo "ERROR: Non-zero exit from generate_cinder_opts.py."
+    echo "       See output above for details."
+    echo "#################################################"
+    mv cinder/opts.py.orig cinder/opts.py
     exit 1
-else
-    mv cinder/opts.py cinder/opts.py.orig
-    tox -e genopts &> tox-genops.log
-    if [ $? -ne 0 ]; then
-        cat tox-genops.log >&2
-        echo -en "\n\n#################################################"
-        echo -en "\nERROR: Non-zero exit from generate_cinder_opts.py."
-        echo -en "\n       See output above for details.\n"
-        echo -en "#################################################\n"
-        mv cinder/opts.py.orig cinder/opts.py
-        exit 1
-    else
-        diff cinder/opts.py.orig cinder/opts.py
-        if [ $? -ne 0 ]; then
-            echo -en "\n\n########################################################"
-            echo -en "\nERROR: Configuration options change detected."
-            echo -en "\n       A new cinder/opts.py file must be generated."
-            echo -en "\n       Run 'tox -e genopts' from the base directory"
-            echo -en "\n       and add the result to your commit."
-            echo -en "\n########################################################\n\n"
-            rm cinder/opts.py
-            mv cinder/opts.py.orig cinder/opts.py
-            exit 1
-        else
-            rm cinder/opts.py.orig
-        fi
-    fi
 fi
+
+diff cinder/opts.py.orig cinder/opts.py
+if [ $? -ne 0 ]; then
+    echo ""
+    echo "########################################################"
+    echo "ERROR: Configuration options change detected."
+    echo "       A new cinder/opts.py file must be generated."
+    echo "       Run 'tox -e genopts' from the base directory"
+    echo "       and add the result to your commit."
+    echo "########################################################"
+    rm cinder/opts.py
+    mv cinder/opts.py.orig cinder/opts.py
+    exit 1
+fi
+
+rm cinder/opts.py.orig