os-net-config not run when conf is empty and re-introduce exception.

There may be cases where os-net-config is empty leading to issue when
we force the run during its special treatment in upgrade/update.

Piggy back in this review is re-adding the os-net-config special
handling to update and non-controller.  But it’s more robust now it
won’t run the command unconditionally, it needs:
 - os-net-config to be upgraded
 - /etc/os-net-config/config.json to exist and not be empty.

Another improvement is that it will prevent any networking cut during
its run as we are using the –no-activate flag.

Change-Id: Ie1b88d5cac22fca5b0b325b1dd8c81d65b63acb8
Closes-Bug: #1728889

extraconfig/tasks/major_upgrade_ceph_storage.sh

@@ -8,6 +8,7 @@ set -o pipefail
 
 UPGRADE_SCRIPT=/root/tripleo_upgrade_node.sh
 
+declare -f update_os_net_config > $UPGRADE_SCRIPT
 declare -f special_case_ovs_upgrade_if_needed > $UPGRADE_SCRIPT
 declare -f update_network >> $UPGRADE_SCRIPT
 # use >> here so we don't lose the declaration we added above

extraconfig/tasks/major_upgrade_compute.sh

@@ -19,6 +19,7 @@ set -eu
 crudini  --set /etc/nova/nova.conf upgrade_levels compute $upgrade_level_nova_compute
 
 # Special-case OVS for https://bugs.launchpad.net/tripleo/+bug/1669714
+$(declare -f update_os_net_config)
 $(declare -f special_case_ovs_upgrade_if_needed)
 $(declare -f update_network)
 update_network

extraconfig/tasks/major_upgrade_controller_pacemaker_2.sh

@@ -111,8 +111,7 @@ if [ $DO_MYSQL_UPGRADE -eq 1 ]; then
     mv /var/lib/mysql $MYSQL_TEMP_UPGRADE_BACKUP_DIR
 fi
 
-update_os_net_config
-# Special-case OVS for https://bugs.launchpad.net/tripleo/+bug/1669714
+# Special-case for network.
 update_network
 
 if grep -q '^pipeline = ssl_header_handler faultwrap osvolumeversionapp' /etc/cinder/api-paste.ini; then

extraconfig/tasks/major_upgrade_object_storage.sh

@@ -23,6 +23,7 @@ function systemctl_swift {
     done
 }
 
+$(declare -f update_os_net_config)
 $(declare -f special_case_ovs_upgrade_if_needed)
 $(declare -f update_network)
 update_network

extraconfig/tasks/pacemaker_common_functions.sh

@@ -353,26 +353,30 @@ function update_os_net_config() {
   if [ -n "${need_update}" ]; then
       yum -q -y update os-net-config
       local return_code=$?
-      log_debug "yum update os-net-config return code: $return_code"
-
-      # We're just make sure that os-net-config won't ifdown/ifup
-      # network interfaces.  The current set of changes (Tue Oct 3
-      # 17:38:37 CEST 2017) doesn't require the os-net-config change
-      # to be taken live.  They will be at next reboot.
-      os-net-config --no-activate -c /etc/os-net-config/config.json -v \
-                    --detailed-exit-codes
-      local os_net_retval=$?
-      if [[ $os_net_retval == 2 ]]; then
-          log_debug "os-net-config: interface configuration files updated successfully"
-      elif [[ $os_net_retval != 0 ]]; then
-          log_debug "ERROR: os-net-config configuration failed"
-          exit $os_net_retval
+      echo "`date` yum update os-net-config return code: $return_code"
+      if [ -s "/etc/os-net-config/config.json" ]; then
+          # We're just make sure that os-net-config won't ifdown/ifup
+          # network interfaces.  The current set of changes (Tue Oct 3
+          # 17:38:37 CEST 2017) doesn't require the os-net-config change
+          # to be taken live.  They will be at next reboot.
+          os-net-config --no-activate -c /etc/os-net-config/config.json -v \
+                        --detailed-exit-codes
+          local os_net_retval=$?
+          if [[ $os_net_retval == 2 ]]; then
+              echo "`date` os-net-config: interface configuration files updated successfully"
+          elif [[ $os_net_retval != 0 ]]; then
+              echo "`date` ERROR: os-net-config configuration failed"
+              exit $os_net_retval
+          fi
+      else
+          echo "`date` /etc/os-net-config/config.json doesn't exist or is empty.  No need to run os-net-config."
       fi
   fi
   set -e
 }
 
 function update_network() {
+    update_os_net_config
     # special case https://bugs.launchpad.net/tripleo/+bug/1635205 +bug/1669714
     special_case_ovs_upgrade_if_needed
 }