Remove stop nova processes from upgrade-nova

stop-base already stop services, so don't need to do it again in
upgrade-nova. This is needed So we can keep the old nova-compute up for
rolling upgrade testing. Instead of killing the entire screen process
kill all the services inside of it.

stop-base is the preferred place to manage the stop logic, because it
has access to the base devstack's stop-* commands.

Change-Id: Ifa2b6305f1f6bbe41407ca12a0f3cbc99b09f301

functions

@@ -1104,6 +1104,29 @@ function screen_it {
     fi
 }
 
+# Stop a service in screen
+# If a PID is available use it, kill the whole process group via TERM
+# If screen is being used kill the screen window; this will catch processes
+# that did not leave a PID behind
+# screen_stop service
+function screen_stop() {
+    SCREEN_NAME=${SCREEN_NAME:-stack}
+    SERVICE_DIR=${SERVICE_DIR:-${DEST}/status}
+    USE_SCREEN=$(trueorfalse True $USE_SCREEN)
+
+    if is_service_enabled $1; then
+        # Kill via pid if we have one available
+        if [[ -r $SERVICE_DIR/$SCREEN_NAME/$1.pid ]]; then
+            pkill -TERM -P -$(cat $SERVICE_DIR/$SCREEN_NAME/$1.pid)
+            rm $SERVICE_DIR/$SCREEN_NAME/$1.pid
+        fi
+        if [[ "$USE_SCREEN" = "True" ]]; then
+            # Clean up the screen window
+            screen -S $SCREEN_NAME -p $1 -X kill
+        fi
+    fi
+}
+
 
 # Screen rc file builder
 # screen_rc service "command-line"

prep-target

@@ -71,9 +71,6 @@ fi
 # Get target config
 source $TARGET_DEVSTACK_DIR/stackrc
 
-# Create a new named screen to run processes in
-screen -d -m -S $SCREEN_NAME -t shell -s /bin/bash
-sleep 1
 # Set a reasonable statusbar
 SCREEN_HARDSTATUS=${SCREEN_HARDSTATUS:-'%{= .} %-Lw%{= .}%> %n%f %t*%{= .}%+Lw%< %-=%{g}(%{d}%H/%l%{g})'}
 screen -r $SCREEN_NAME -X hardstatus alwayslastline "$SCREEN_HARDSTATUS"

stop-base

@@ -33,14 +33,15 @@ set -o xtrace
 
 echo "Shutting down devstack in screen"
 
-# Shut down running processes in screen - most of them
+# Kill running processes
 SCREEN=$(which screen)
 if [[ -n "$SCREEN" ]]; then
-    SESSION=$(screen -ls | awk "/[0-9].${SCREEN_NAME}/ { print \$1 }")
-    if [[ -n "$SESSION" ]]; then
-        screen -X -S $SESSION quit
-        sleep 2
-    fi
+    OIFS=$IFS
+    IFS=,
+    for serv in $ENABLED_SERVICES; do
+        screen_stop $serv
+    done
+    IFS=$OIFS
 fi
 
 # Swift runs daemons

upgrade-nova

@@ -49,11 +49,6 @@ TOP_DIR=$TARGET_DEVSTACK_DIR
 # Upgrade Nova
 # ============
 
-# Kill running Nova processes
-for serv in n-api n-cond n-cauth n-cpu n-crt n-net n-novnc n-obj n-sch n-vol n-xvnc; do
-    screen -S $SCREEN_NAME -p $serv -X kill
-done
-
 MYSQL_HOST=${MYSQL_HOST:-localhost}
 MYSQL_USER=${MYSQL_USER:-root}
 BASE_SQL_CONN=$(source $BASE_DEVSTACK_DIR/stackrc; echo ${BASE_SQL_CONN:-mysql://$MYSQL_USER:$MYSQL_PASSWORD@$MYSQL_HOST})