Use upper-constraints for tox envs

Pin tox environments to upper-constraints to avoid conflicts with
library releases.

Change-Id: I17664e0794de05fb9661050018dff2a07b077826
Closes-Bug: #1628597

tools/tox_install.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+
+# Client constraint file contains this client version pin that is in conflict
+# with installing the client from source. We should remove the version pin in
+# the constraints file before applying it for from-source installation.
+
+CONSTRAINTS_FILE=$1
+shift 1
+
+set -e
+
+# NOTE(tonyb): Place this in the tox enviroment's log dir so it will get
+# published to logs.openstack.org for easy debugging.
+localfile="$VIRTUAL_ENV/log/upper-constraints.txt"
+
+if [[ $CONSTRAINTS_FILE != http* ]]; then
+    CONSTRAINTS_FILE=file://$CONSTRAINTS_FILE
+fi
+# NOTE(tonyb): need to add curl to bindep.txt if the project supports bindep
+curl $CONSTRAINTS_FILE --insecure --progress-bar --output $localfile
+
+pip install -c$localfile openstack-requirements
+
+# 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 -- $CLIENT_NAME
+
+pip install -c$localfile -U $*
+exit $?

tox.ini

@@ -5,9 +5,13 @@ skipsdist = True
 
 [testenv]
 usedevelop = True
-install_command = pip install -U {opts} {packages}
+passenv = ZUUL_CACHE_DIR
+          REQUIREMENTS_PIP_LOCATION
+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}
+   BRANCH_NAME=master
+   CLIENT_NAME=os-client-config
 deps = -r{toxinidir}/test-requirements.txt
 commands = python setup.py testr --slowest --testr-args='{posargs}'