Get tempest via zuul-cloner if needed and it is available

Change-Id: I70f402202f99a989ef5e95213669f4ca9f7b706f

tools/tox_install.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+# Many of neutron's repos suffer from the problem of depending on neutron,
+# but it not existing on pypi. -- Well, that's the usual issue, but in
+# neutron's case, we want to import tempest directly for the api tests.
+
+# This wrapper for tox's package installer will use the existing package
+# if it exists, else use zuul-cloner if that program exists, else grab it
+# from neutron master via a hard-coded URL. That last case should only
+# happen with devs running unit tests locally.
+
+# From the tox.ini config page:
+# install_command=ARGV
+# default:
+# pip install {opts} {packages}
+
+ZUUL_CLONER=/usr/zuul-env/bin/zuul-cloner
+tempest_installed=$(python -c "import tempest" 2>/dev/null ; echo $?)
+
+set -e
+
+if [ $tempest_installed -eq 0 ]; then
+    echo "Tempest already installed; using existing package"
+elif [ -x "$ZUUL_CLONER" ]; then
+    export ZUUL_BRANCH=${ZUUL_BRANCH-$BRANCH}
+    pushd /tmp
+    $ZUUL_CLONER --cache-dir \
+        /opt/git \
+        git://git.openstack.org \
+        openstack/tempest
+    pip install -e openstack/tempest
+    popd
+else
+    pip install -U -egit+https://git.openstack.org/openstack/tempest#egg=tempest
+fi
+
+pip install -U $*

tox.ini

@@ -26,17 +26,15 @@ setenv = {[testenv]setenv}
          OS_TEST_PATH=./neutron/tests/api
          TEMPEST_CONFIG_DIR={env:TEMPEST_CONFIG_DIR:/opt/stack/tempest/etc}
          OS_TEST_API_WITH_REST=1
-deps =
-  {[testenv]deps}
-  git+https://git.openstack.org/openstack/tempest#egg=tempest
+install_command =
+                  constraints: {[testenv:common-constraints]install_command}
+                  {toxinidir}/tools/tox_install.sh {opts} {packages}
 
 [testenv:api-constraints]
 basepython = {[testenv:api]basepython}
-install_command = {[testenv:common-constraints]install_command}
 passenv = {[testenv:api]passenv}
 setenv = {[testenv:api]setenv}
-deps =
-  {[testenv:api]deps}
+install_command = {toxinidir}/tools/tox_install.sh -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 
 [testenv:common]
 # Fake job to define environment variables shared between dsvm/non-dsvm jobs