Add mechanism to automatically load additional projects

This adds an extras.d directory to contain startup scripts that
stack.sh runs automatically at the end.  Similar to local.sh
except the scripts are sourced into the stack.sh process rather
than executed as a child process.  This gives them complete
access to the stack.sh environment.

Convert Tempest to use this format as an example.

Change-Id: Ibc95e6aaecf4211da948319eb452293ae4357780

extras.d/80-tempest.sh

@@ -0,0 +1,20 @@
+# tempest.sh - DevStack extras script
+
+source $TOP_DIR/lib/tempest
+
+if [[ "$1" == "stack" ]]; then
+    # Configure Tempest last to ensure that the runtime configuration of
+    # the various OpenStack services can be queried.
+    if is_service_enabled tempest; then
+        echo_summary "Configuring Tempest"
+        install_tempest
+        configure_tempest
+    fi
+fi
+
+if [[ "$1" == "unstack" ]]; then
+    # no-op
+    :
+fi
+
+

extras.d/README

@@ -0,0 +1,14 @@
+The extras.d directory contains project initialization scripts to be
+sourced by stack.sh at the end of its run.  This is expected to be
+used by external projects that want to be configured, started and
+stopped with DevStack.
+
+Order is controlled by prefixing the script names with the a two digit
+sequence number.  Script names must end with '.sh'.  This provides a
+convenient way to disable scripts by simoy renaming them.
+
+DevStack reserves the sequence numbers 00 through 09 and 90 through 99
+for its own use.
+
+The scripts are called with an argument of 'stack' by stack.sh and
+with an argument of 'unstack' by unstack.sh.

stack.sh

@@ -321,7 +321,6 @@ source $TOP_DIR/lib/swift
 source $TOP_DIR/lib/ceilometer
 source $TOP_DIR/lib/heat
 source $TOP_DIR/lib/quantum
-source $TOP_DIR/lib/tempest
 source $TOP_DIR/lib/baremetal
 
 # Set the destination directories for OpenStack projects
@@ -775,9 +774,6 @@ fi
 if is_service_enabled ceilometer; then
     install_ceilometer
 fi
-if is_service_enabled tempest; then
-    install_tempest
-fi
 
 
 # Initialization
@@ -1314,16 +1310,6 @@ if is_service_enabled nova && is_baremetal; then
     screen_it baremetal "nova-baremetal-deploy-helper"
 fi
 
-# Configure Tempest last to ensure that the runtime configuration of
-# the various OpenStack services can be queried.
-if is_service_enabled tempest; then
-    echo_summary "Configuring Tempest"
-    configure_tempest
-    echo '**************************************************'
-    echo_summary "Finished Configuring Tempest"
-    echo '**************************************************'
-fi
-
 # Save some values we generated for later use
 CURRENT_RUN_TIME=$(date "+$TIMESTAMP_FORMAT")
 echo "# $CURRENT_RUN_TIME" >$TOP_DIR/.stackenv
@@ -1333,6 +1319,16 @@ for i in BASE_SQL_CONN ENABLED_SERVICES HOST_IP LOGFILE \
 done
 
 
+# Run extras
+# ==========
+
+if [[ -d $TOP_DIR/extras.d ]]; then
+    for i in $TOP_DIR/extras.d/*.sh; do
+        [[ -r $i ]] && source $i stack
+    done
+fi
+
+
 # Run local script
 # ================
 

unstack.sh

@@ -39,6 +39,15 @@ if [[ "$1" == "--all" ]]; then
     UNSTACK_ALL=${UNSTACK_ALL:-1}
 fi
 
+# Run extras
+# ==========
+
+if [[ -d $TOP_DIR/extras.d ]]; then
+    for i in $TOP_DIR/extras.d/*.sh; do
+        [[ -r $i ]] && source $i unstack
+    done
+fi
+
 if [[ "$Q_USE_DEBUG_COMMAND" == "True" ]]; then
     source $TOP_DIR/openrc
     teardown_quantum_debug