Add support for OS_* environment vars

Add the OS_* env variables to mirror the NOVA_* vars; example:
setting OS_USERNAME will override NOVA_USERNAME in the clients and
tools, but if left unset it defaults to NOVA_USERNAME.

Adds exercises/client-env.sh to test operation of command-line
clients with only the OS_* variables set

Addresses bug 897304, http://wiki.openstack.org/CLIAuth

Change-Id: I72450153541072fe8026a82748cfcd1cf5ed31d8
diff --git a/exercises/client-env.sh b/exercises/client-env.sh
new file mode 100755
index 0000000..f4172bc
--- /dev/null
+++ b/exercises/client-env.sh
@@ -0,0 +1,166 @@
+#!/usr/bin/env bash
+
+# Test OpenStack client enviroment variable handling
+
+# Verify client workage
+VERIFY=${1:-""}
+
+# Settings
+# ========
+
+# Use openrc + stackrc + localrc for settings
+pushd $(cd $(dirname "$0")/.. && pwd) >/dev/null
+source ./openrc
+popd >/dev/null
+
+# Unset all of the known NOVA_ vars
+unset NOVA_API_KEY
+unset NOVA_ENDPOINT_NAME
+unset NOVA_PASSWORD
+unset NOVA_PROJECT_ID
+unset NOVA_REGION_NAME
+unset NOVA_URL
+unset NOVA_USERNAME
+unset NOVA_VERSION
+
+# Make sure we have the vars we are expecting
+function is_set() {
+    local var=\$"$1"
+    eval echo $1=$var
+    if eval "[ -z $var ]"; then
+        return 1
+    fi
+    return 0
+}
+
+for i in OS_TENANT_NAME OS_USERNAME OS_PASSWORD OS_AUTH_URL; do
+    is_set $i
+    if [[ $? -ne 0 ]]; then
+        ABORT=1
+    fi
+done
+if [[ -n "$ABORT" ]]; then
+    exit 1
+fi
+
+# Set global return
+RETURN=0
+
+# Keystone client
+# ---------------
+if [[ "$ENABLED_SERVICES" =~ "key" ]]; then
+    if [[ "$SKIP_EXERCISES" =~ "key" ]] ; then
+        STATUS_KEYSTONE="Skipped"
+    else
+        if [[ -n "$VERIFY" ]]; then
+            # Save original environment
+            xOS_AUTH_URL=$OS_AUTH_URL
+            xOS_TENANT_NAME=$OS_TENANT_NAME
+            xOS_USERNAME=$OS_USERNAME
+            xOS_PASSWORD=$OS_PASSWORD
+            # keystone can't handle a trailing '/'
+            export OS_AUTH_URL=${OS_AUTH_URL%/}
+            # does any non-admin request work?
+            export OS_USERNAME=admin
+            export OS_TENANT_NAME=admin
+        fi
+
+        echo -e "\nTest Keystone"
+        if keystone service-list; then
+            STATUS_KEYSTONE="Succeeded"
+        else
+            STATUS_KEYSTONE="Failed"
+            RETURN=1
+        fi
+        if [[ -n "$VERIFY" ]]; then
+            # Save original environment
+            OS_AUTH_URL=$xOS_AUTH_URL
+            OS_TENANT_NAME=$xOS_TENANT_NAME
+            OS_USERNAME=$xOS_USERNAME
+            OS_PASSWORD=$xOS_PASSWORD
+        fi
+    fi
+fi
+
+# Nova client
+# -----------
+
+if [[ "$ENABLED_SERVICES" =~ "n-api" ]]; then
+    if [[ "$SKIP_EXERCISES" =~ "n-api" ]] ; then
+        STATUS_NOVA="Skipped"
+    else
+        if [[ -n "$VERIFY" ]]; then
+            # Known novaclient breakage:
+            #  NOVA_VERSION must be set or nova silently fails
+            export NOVA_VERSION=2
+        fi
+
+        echo -e "\nTest Nova"
+        if nova flavor-list; then
+            STATUS_NOVA="Succeeded"
+        else
+            STATUS_NOVA="Failed"
+            RETURN=1
+        fi
+    fi
+fi
+
+# Glance client
+# -------------
+
+if [[ "$ENABLED_SERVICES" =~ "g-api" ]]; then
+    if [[ "$SKIP_EXERCISES" =~ "g-api" ]] ; then
+        STATUS_GLANCE="Skipped"
+    else
+        if [[ -n "$VERIFY" ]]; then
+            # Known glance client differage:
+            export OS_AUTH_TENANT=$OS_TENANT_NAME
+            export OS_AUTH_USER=$OS_USERNAME
+            export OS_AUTH_KEY=$OS_PASSWORD
+            export OS_AUTH_STRATEGY=keystone
+        fi
+
+        echo -e "\nTest Glance"
+        if glance index; then
+            STATUS_GLANCE="Succeeded"
+        else
+            STATUS_GLANCE="Failed"
+            RETURN=1
+        fi
+    fi
+fi
+
+# Swift client
+# ------------
+
+if [[ "$ENABLED_SERVICES" =~ "swift" ]]; then
+    if [[ "$SKIP_EXERCISES" =~ "swift" ]] ; then
+        STATUS_SWIFT="Skipped"
+    else
+        echo -e "\nTest Swift"
+        # FIXME(dtroyer): implement swift test
+        if true; then
+            STATUS_SWIFT="Succeeded"
+        else
+            STATUS_SWIFT="Failed"
+            RETURN=1
+        fi
+    fi
+fi
+
+# Results
+# -------
+
+function report() {
+    if [[ -n "$2" ]]; then
+        echo "$1: $2"
+    fi
+}
+
+echo -e "\n"
+report "Keystone" $STATUS_KEYSTONE
+report "Nova" $STATUS_NOVA
+report "Glance" $STATUS_GLANCE
+report "Swift" $STATUS_SWIFT
+
+exit $RETURN