fix(genesis): restore failed network refreshes

xCAT-genesis-builder/oe/meta-xcat-genesis/recipes-core/xcat-genesis-init/files/genesis-network-refresh

@@ -6,6 +6,40 @@ network_file=${XCAT_NETWORK_FILE:-$state_dir/genesis.env}
 network_state_command=${XCAT_NETWORK_STATE_COMMAND:-/usr/libexec/xcat/genesis-network-state}
 sys_class_net=${XCAT_SYS_CLASS_NET:-/sys/class/net}
 callback=${1:-restart}
+declare -a rollback_interfaces=()
+declare -a rollback_connections=()
+rollback_required=0
+
+remember_connection() {
+    local interface=$1 connection
+
+    connection=$(nmcli -g GENERAL.CON-UUID device show "$interface" 2>/dev/null \
+        || true)
+    rollback_interfaces+=("$interface")
+    rollback_connections+=("$connection")
+}
+
+restore_connections() {
+    local result=$? index interface connection
+
+    trap - EXIT
+    if ((result != 0 && rollback_required == 1)); then
+        logger -t xcat-genesis-network-refresh -- \
+            'network refresh failed; restoring previous connections'
+        for ((index = 0; index < ${#rollback_interfaces[@]}; index++)); do
+            interface=${rollback_interfaces[index]}
+            connection=${rollback_connections[index]}
+            if [[ -n $connection ]]; then
+                nmcli --wait 30 connection up uuid "$connection" \
+                    ifname "$interface" >/dev/null 2>&1 || true
+            else
+                nmcli --wait 30 device connect "$interface" >/dev/null 2>&1 \
+                    || true
+            fi
+        done
+    fi
+    exit "$result"
+}
 
 [[ -r $network_file ]] || exit 1
 # shellcheck disable=SC1090
@@ -27,8 +61,12 @@ fi
 for interface in "${requested_interfaces[@]}"; do
     [[ $interface =~ ^[A-Za-z0-9_.-]+$ && -e $sys_class_net/$interface ]] \
         || exit 1
+    remember_connection "$interface"
 done
 
+rollback_required=1
+trap restore_connections EXIT
+
 if [[ $callback = 'restart ('*')' ]]; then
     while IFS=: read -r interface device_type; do
         [[ $device_type = ethernet ]] || continue
@@ -39,9 +77,11 @@ if [[ $callback = 'restart ('*')' ]]; then
                 break
             fi
         done
-        ((keep == 1)) \
-            || nmcli --wait 10 device disconnect "$interface" >/dev/null 2>&1 \
-            || true
+        if ((keep == 0)); then
+            remember_connection "$interface"
+            nmcli --wait 10 device disconnect "$interface" >/dev/null 2>&1 \
+                || true
+        fi
     done < <(nmcli -t -f DEVICE,TYPE device status 2>/dev/null || true)
 fi
 
@@ -53,3 +93,5 @@ for interface in "${requested_interfaces[@]}"; do
 done
 
 "$network_state_command"
+rollback_required=0
+trap - EXIT