[doc] Note lack of constraints is a choice

Change-Id: Id8cdb746ea1eaf66835a9b9cfbb6b11792a5f49d

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

@@ -14,6 +14,7 @@ deps = .[test,zake,ipc,memcached,mysql,etcd]
     mysql: .[mysql]
     etcd: .[etcd]
     consul: .[consul]
+# NOTE(tonyb): This project has chosen to *NOT* consume upper-constraints.txt
 commands = {toxinidir}/tools/pretty_tox.sh "{posargs}"
 
 [testenv:venv]