Add Constraints support

Adding constraints support to libraries is slightly more complex than
services as the libraries themselves are listed in upper-constraints.txt
which leads to errors that you can't install a specific version and a
constrained version.

This change adds constraints support by also adding a helper script to
edit the constraints to remove taskflow.

Change-Id: I89a14733295748fff2a30f038084d75596204083

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

@@ -1,5 +1,5 @@
 [tox]
-minversion = 1.6
+minversion = 2.0
 envlist = cover,
     docs,
     pep8,
@@ -10,6 +10,10 @@ envlist = cover,
     update-states
 
 [testenv]
+setenv = VIRTUAL_ENV={envdir}
+         BRANCH_NAME=master
+         CLIENT_NAME=taskflow
+install_command = {toxinidir}/tools/tox_install.sh {env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 # We need to install a bit more than just `test' because those drivers have
 # custom tests that we always run
 deps = .[test,workers,zookeeper,database,redis,eventlet,doc]
@@ -28,7 +32,6 @@ commands = {toxinidir}/tools/update_states.sh
 commands = flake8 {posargs}
 
 [testenv:pylint]
-setenv = VIRTUAL_ENV={envdir}
 deps = {[testenv]deps}
     pylint==0.26.0
 commands = pylint --rcfile=pylintrc taskflow