Merge (don't overwrite) $NOVA_CPU_CONF

Per the referenced bug, $NOVA_CPU_CONF was previously being initialized
by copying $NOVA_CONF, thereby trashing any values already configured in
$NOVA_CPU_CONF.

With this commit, we merge the values from $NOVA_CPU_CONF in after the
copy.

Note that this makes use of the merge_config_file function, which is
defined in inc/meta-config, which wasn't being sourced from every code
path that hit start_nova_compute; so this commit also moves that import
from stack.sh to functions (next to the other imports from inc/, which
makes sense anyway).

Change-Id: Id3e2baa2221e13f512f8dcf1248e1e15b6a7597f
Closes-Bug: #1802143

functions

@@ -18,6 +18,7 @@ declare -r -g _DEVSTACK_FUNCTIONS=1
 FUNC_DIR=$(cd $(dirname "${BASH_SOURCE:-$0}") && pwd)
 source ${FUNC_DIR}/functions-common
 source ${FUNC_DIR}/inc/ini-config
+source ${FUNC_DIR}/inc/meta-config
 source ${FUNC_DIR}/inc/python
 source ${FUNC_DIR}/inc/rootwrap
 

lib/nova

@@ -838,7 +838,10 @@ function start_nova_compute {
 
     local compute_cell_conf=$NOVA_CONF
 
+    # Bug #1802143: $NOVA_CPU_CONF is constructed by first copying $NOVA_CONF...
     cp $compute_cell_conf $NOVA_CPU_CONF
+    # ...and then adding/overriding anything explicitly set in $NOVA_CPU_CONF
+    merge_config_file $TOP_DIR/local.conf post-config '$NOVA_CPU_CONF'
 
     if [[ "${CELLSV2_SETUP}" == "singleconductor" ]]; then
         # NOTE(danms): Grenade doesn't setup multi-cell rabbit, so

stack.sh

@@ -167,9 +167,6 @@ LAST_SPINNER_PID=""
 # Import common functions
 source $TOP_DIR/functions
 
-# Import config functions
-source $TOP_DIR/inc/meta-config
-
 # Import 'public' stack.sh functions
 source $TOP_DIR/lib/stack