Add support for upper-constraints.txt for all tox targets

This will make neutron-lib gate use dependency versions that are sanity
checked by jobs in openstack/requirements gate.

Since the library is itself in upper-constraints.txt file, we should
remove its entry from the constraints file before applying it, otherwise
pip will fail due to version conflict between what's in the current
library repo and what's in constraints file.

Change-Id: I6a708e7b618f2f2da9c9210a19e4d4e4ac370462

tools/tox_install.sh

@@ -0,0 +1,52 @@
+#!/usr/bin/env bash
+
+# Library constraint file contains this library version pin that is in conflict
+# with installing the library from source. We should replace the version pin in
+# the constraints file before applying it for from-source installation.
+
+ZUUL_CLONER=/usr/zuul-env/bin/zuul-cloner
+BRANCH_NAME=master
+LIB_NAME=neutron-lib
+requirements_installed=$(echo "import openstack_requirements" | python 2>/dev/null ; echo $?)
+
+set -e
+
+CONSTRAINTS_FILE=$1
+shift
+
+install_cmd="pip install"
+mydir=$(mktemp -dt "$LIB_NAME-tox_install-XXXXXXX")
+trap "rm -rf $mydir" EXIT
+localfile=$mydir/upper-constraints.txt
+if [[ $CONSTRAINTS_FILE != http* ]]; then
+    CONSTRAINTS_FILE=file://$CONSTRAINTS_FILE
+fi
+curl $CONSTRAINTS_FILE -k -o $localfile
+install_cmd="$install_cmd -c$localfile"
+
+if [ $requirements_installed -eq 0 ]; then
+    echo "Requirements already installed; using existing package"
+elif [ -x "$ZUUL_CLONER" ]; then
+    pushd $mydir
+    $ZUUL_CLONER --cache-dir \
+        /opt/git \
+        --branch $BRANCH_NAME \
+        git://git.openstack.org \
+        openstack/requirements
+    cd openstack/requirements
+    $install_cmd -e .
+    popd
+else
+    if [ -z "$REQUIREMENTS_PIP_LOCATION" ]; then
+        REQUIREMENTS_PIP_LOCATION="git+https://git.openstack.org/openstack/requirements@$BRANCH_NAME#egg=requirements"
+    fi
+    $install_cmd -U -e ${REQUIREMENTS_PIP_LOCATION}
+fi
+
+# This is the main purpose of the script: Allow local installation of
+# the current repo. It is listed in constraints file and thus any
+# install will be constrained and we need to unconstrain it.
+edit-constraints $localfile -- $LIB_NAME "-e file://$PWD#egg=$LIB_NAME"
+
+$install_cmd -U $*
+exit $?

tox.ini

@@ -6,7 +6,7 @@ skipsdist = True
 [testenv]
 usedevelop = True
 passenv = TRACE_FAILONLY
-install_command = pip install -U {opts} {packages}
+install_command = {toxinidir}/tools/tox_install.sh {env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 setenv =
   VIRTUAL_ENV={envdir}
   PYTHONWARNINGS=default::DeprecationWarning