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 diskimage-builder.

Change-Id: I795800589ea1491efd0e489a38b60e6adf33e7f3

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

@@ -1,11 +1,15 @@
 [tox]
 envlist = py35,py27,pep8,pylint
-minversion = 1.6
+minversion = 2.0
 skipsdist = True
 
 [testenv]
 usedevelop = True
-install_command = pip install -U {opts} {packages}
+setenv =
+    VIRTUAL_ENV={envdir}
+    BRANCH_NAME=master
+    CLIENT_NAME=diskimage-builder
+install_command = {toxinidir}/tools/tox_install.sh {env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt} {opts} {packages}
 deps= -r{toxinidir}/requirements.txt
       -r{toxinidir}/test-requirements.txt
 commands=
@@ -29,6 +33,8 @@ envdir = {toxworkdir}/venv
 commands = {toxinidir}/tests/run_functests.sh {posargs}
 
 [testenv:cover]
+setenv =
+    {[testenv]setenv}
 # NOTE: this is "setup.py test" (*not* testr) which is a pbr wrapper
 # around testr.  This understands --coverage-package-name which we
 # need due to underscore issues.