Adds check for existing yum process during the legacy minor update

Checks for an existing /var/run/yum.pid and exit 1 with an error
message saying why.

Change-Id: I374eeb4164a8007ae67fea2796eac109fffdef97
Closes-Bug: 1704131

extraconfig/tasks/pacemaker_common_functions.sh

@@ -371,3 +371,15 @@ function fixup_wrong_ipv6_vip {
         fi
     )
 }
+
+# https://bugs.launchpad.net/tripleo/+bug/1704131 guard against yum update
+# waiting for an existing process until the heat stack time out
+function check_for_yum_lock {
+    if [[ -f /var/run/yum.pid ]] ; then
+        ERR="ERROR existing yum.pid detected - can't continue! Please ensure
+there is no other package update process for the duration of the minor update
+worfklow. Exiting."
+        echo $ERR
+        exit 1
+   fi
+}

extraconfig/tasks/yum_update.sh

@@ -93,6 +93,7 @@ if [[ "$pacemaker_status" == "active" ]] ; then
     fi
 else
     echo "Upgrading openstack-puppet-modules and its dependencies"
+    check_for_yum_lock
     yum -q -y update openstack-puppet-modules
     yum deplist openstack-puppet-modules | awk '/dependency/{print $2}' | xargs yum -q -y update
     echo "Upgrading other packages is handled by config management tooling"
@@ -102,8 +103,9 @@ fi
 
 command=${command:-update}
 full_command="yum -q -y $command $command_arguments"
-echo "Running: $full_command"
 
+echo "Running: $full_command"
+check_for_yum_lock
 result=$($full_command)
 return_code=$?
 echo "$result"