Fix zuul_cloner errors during tox job setup

Since [1], Tempest is a pip installable package, and that prevents zuul_cloner
to work correctly. This change moves away from the existing logic in tox_install,
and adds tempest as an explicit requirement for the api job. This is in fact
the only tox target that needs Tempest to work.

tox_install.sh has become less important now, but cleanup is left as follow
up, to speed up gate salvation.

[1] I25eac915c977ebaedced66ac896c5dd77259d193

Change-Id: I00d882dde77a687ecb57ec200a34fd96256ad87a
(cherry picked from commit 8a6913c534)

neutron/tests/api/requirements.txt

@@ -0,0 +1,7 @@
+# Additional requirements for api tests
+
+# The order of packages is significant, because pip processes them in the order
+# of appearance. Changing the order has an impact on the overall integration
+# process, which may cause wedges in the gate later.
+
+tempest>=10.0.0  # Apache-2.0

tools/tox_install.sh

@@ -9,10 +9,7 @@
 # from neutron master via a hard-coded URL. That last case should only
 # happen with devs running unit tests locally.
 
-ZUUL_CLONER=/usr/zuul-env/bin/zuul-cloner
-tempest_installed=$(python -c "import tempest" 2>/dev/null ; echo $?)
-
-set -e
+set -eux
 
 install_cmd="pip install"
 
@@ -23,19 +20,4 @@ if [ "$CONSTRAINTS_FILE" != "unconstrained" ]; then
     install_cmd="$install_cmd -c$CONSTRAINTS_FILE"
 fi
 
-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
-    $install_cmd -e openstack/tempest
-    popd
-else
-    $install_cmd -U -egit+https://git.openstack.org/openstack/tempest#egg=tempest
-fi
-
 $install_cmd -U $*

tox.ini

@@ -24,6 +24,9 @@ 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}
+  -r{toxinidir}/neutron/tests/api/requirements.txt
 
 [testenv:common]
 # Fake job to define environment variables shared between dsvm/non-dsvm jobs