Publish cross-test runner as part of oslotest

Move the latest version of run_cross_test.sh from the incubator here to
oslotest and rename it so we can publish it as a tool that comes with
oslotest instead of syncing it into the other projects.

Change-Id: I1aec3bda9e46b1667cfd7b68aa2d654327d1c8fb

setup.cfg

@@ -24,6 +24,7 @@ packages =
     oslotest
 scripts =
     tools/oslo_debug_helper
+    tools/oslo_run_cross_tests
 
 [global]
 setup-hooks =

tools/oslo_run_cross_tests

@@ -1,12 +1,37 @@
 #!/bin/bash
 #
 # Run cross-project tests
+#
+# Usage:
+#
+#   oslo_run_cross_tests project_dir venv
 
 # Fail the build if any command fails
 set -e
 
 project_dir="$1"
-venv="$2"
+shift
+venv="$1"
+shift
+posargs="$*"
+
+if [ -z "$project_dir" -o -z "$venv" ]
+then
+    cat - <<EOF
+ERROR: Missing argument(s)
+
+Usage:
+
+  $0 PROJECT_DIR VIRTUAL_ENV [POSARGS]
+
+Example, run the python 2.7 tests for python-neutronclient:
+
+  $0 /opt/stack/python-neutronclient py27
+  $0 /opt/stack/nova py27 xenapi
+
+EOF
+    exit 1
+fi
 
 # Set up the virtualenv without running the tests
 (cd $project_dir && tox --notest -e $venv)
@@ -15,18 +40,23 @@ tox_envbin=$project_dir/.tox/$venv/bin
 
 our_name=$(python setup.py --name)
 
+# Build the egg-info, including the source file list,
+# so we install all of the files, even if the package
+# list or name has changed.
+python setup.py egg_info
+
 # Replace the pip-installed package with the version in our source
 # tree. Look to see if we are already installed before trying to
 # uninstall ourselves, to avoid failures from packages that do not use us
 # yet.
 if $tox_envbin/pip freeze | grep -q $our_name
 then
-    $tox_envbin/pip uninstall -y $our_name
+    $tox_envbin/pip uninstall -y $our_name || echo "Ignoring error"
 fi
 $tox_envbin/pip install -U .
 
 # Run the tests
-(cd $project_dir && tox -e $venv)
+(cd $project_dir && tox -e $venv -- $posargs)
 result=$?