Recent virtualenv review cleanups

This is a follow-on to comments in https://review.openstack.org/156356
and https://review.openstack.org/#/c/151513/

* Remove work-around for /var/cache/pip
* Remove WHEELHOUSE setting in tools/build_wheels.sh and use the pip
  default directory '<cwd>/wheelhouse'
* Remove bogus MySQL-python install
* Removed unused bits and clean up pip commands in from tools/build_venvs.sh

Closes-Bug: #1423720
Change-Id: I0283b0dff9146b1b63bd821358505a93566270c6

files/rpms-suse/devlibs

@@ -1,6 +1,6 @@
 libffi-devel  # pyOpenSSL
 libopenssl-devel  # pyOpenSSL
 libxml2-devel  # lxml
-libxslt-dev  # lxml
+libxslt-devel  # lxml
 postgresql-devel  # psycopg2
 python-devel  # pyOpenSSL

lib/databases/postgresql

@@ -102,7 +102,7 @@ EOF
     fi
 
     # Install Python client module
-    pip_install MySQL-python psycopg2
+    pip_install psycopg2
 }
 
 function database_connection_url_postgresql {

stack.sh

@@ -677,14 +677,8 @@ source $TOP_DIR/tools/fixup_stuff.sh
 # Virtual Environment
 # -------------------
 
-# Temporary hack for testing
-# This belongs in d-g functions.sh setup_host() or devstack-vm-gate.sh
-if [[ -d /var/cache/pip ]]; then
-    sudo chown -R $STACK_USER:$STACK_USER /var/cache/pip
-fi
-
 # Pre-build some problematic wheels
-if [[ ! -d ${WHEELHOUSE:-} ]]; then
+if [[ -n ${WHEELHOUSE:-} && ! -d ${WHEELHOUSE:-} ]]; then
     source $TOP_DIR/tools/build_wheels.sh
 fi
 

tools/build_venv.sh

@@ -34,26 +34,13 @@ if [[ -z "$TOP_DIR" ]]; then
 
     source $TOP_DIR/stackrc
 
-    trap err_trap ERR
-
 fi
 
-# Exit on any errors so that errors don't compound
-function err_trap {
-    local r=$?
-    set +o xtrace
-
-    rm -rf $TMP_VENV_PATH
-
-    exit $r
-}
-
 # Build new venv
 virtualenv $VENV_DEST
 
 # Install modern pip
-$VENV_DEST/bin/pip install -U pip
+PIP_VIRTUAL_ENV=$VENV_DEST pip_install -U pip
 
-for pkg in ${MORE_PACKAGES}; do
+# Install additional packages
-    pip_install_venv $VENV_DEST $pkg
+PIP_VIRTUAL_ENV=$VENV_DEST pip_install ${MORE_PACKAGES}
-done

tools/build_wheels.sh

@@ -36,10 +36,6 @@ fi
 # Get additional packages to build
 MORE_PACKAGES="$@"
 
-# Set a fall-back default, assume that since this script is being called
-# package builds are to happen even if WHEELHOUSE is not configured
-export WHEELHOUSE=${WHEELHOUSE:-.wheelhouse}
-
 # Exit on any errors so that errors don't compound
 function err_trap {
     local r=$?