backup-cloud: catch error with :execute workaround

Catching a runtime error here fails... So let's try a workaround
with :execute...

backup-cloud.rsc

@@ -15,7 +15,6 @@
 :local Main do={
   :local ScriptName [ :tostr $1 ];
 
-  :global BackupPassword;
   :global BackupRandomDelay;
   :global Identity;
 
@@ -23,11 +22,13 @@
   :global FormatLine;
   :global HumanReadableNum;
   :global LogPrintExit2;
+  :global MkDir;
   :global RandomDelay;
   :global ScriptFromTerminal;
   :global ScriptLock;
   :global SendNotification2;
   :global SymbolForNotification;
+  :global WaitForFile;
   :global WaitFullyConnected;
 
   :if ([ $ScriptLock $ScriptName ] = false) do={
@@ -39,7 +40,12 @@
     $RandomDelay $BackupRandomDelay;
   }
 
-  :do {
+  :if ([ $MkDir ("tmpfs/backup-cloud") ] = false) do={
+    $LogPrintExit2 error $ScriptName ("Failed creating directory!") true;
+  }
+
+  :execute {
+    :global BackupPassword;
     # we are not interested in output, but print is
     # required to fetch information from cloud
     /system/backup/cloud/print as-value;
@@ -50,6 +56,10 @@
       /system/backup/cloud/upload-file action=create-and-upload \
           password=$BackupPassword;
     }
+    /file/add name="tmpfs/backup-cloud/done";
+  } as-string;
+
+  :if ([ $WaitForFile "tmpfs/backup-cloud/done" ] = true) do={
     :local Cloud [ /system/backup/cloud/get ([ find ]->0) ];
 
     $SendNotification2 ({ origin=$ScriptName; \
@@ -59,12 +69,13 @@
         [ $FormatLine "Name" ($Cloud->"name") ] . "\n" . \
         [ $FormatLine "Size" ([ $HumanReadableNum ($Cloud->"size") 1024 ] . "iB") ] . "\n" . \
         [ $FormatLine "Download key" ($Cloud->"secret-download-key") ]); silent=true });
-  } on-error={
+  } else={
     $SendNotification2 ({ origin=$ScriptName; \
       subject=([ $SymbolForNotification "floppy-disk,warning-sign" ] . "Cloud backup failed"); \
       message=("Failed uploading backup for " . $Identity . " to cloud!\n\n" . [ $DeviceInfo ]) });
     $LogPrintExit2 error $ScriptName ("Failed uploading backup for " . $Identity . " to cloud!") true;
   }
+  /file/remove "tmpfs/backup-cloud";
 }
 
 $Main [ :jobname ];

doc/backup-cloud.md

@@ -12,10 +12,10 @@ Description
 This script uploads
 [binary backup to Mikrotik cloud](https://wiki.mikrotik.com/wiki/Manual:IP/Cloud#Backup).
 
-> ⚠️ **Warning**: The used command can hit errors that a script can not handle.
-> This may result in script termination (where no notification is sent) or
-> malfunction of fetch command (where all up- and downloads break) for some
-> time. Failed notifications are queued then.
+> ⚠️ **Warning**: The used command can hit errors that a script can with
+> workaround only. A notification *should* be sent anyway. But it can result
+> in malfunction of fetch command (where all up- and downloads break) for
+> some time. Failed notifications are queued then.
 
 ### Sample notification
 

global-functions.rsc

@@ -12,7 +12,7 @@
 :local ScriptName [ :jobname ];
 
 # expected configuration version
-:global ExpectedConfigVersion 119;
+:global ExpectedConfigVersion 120;
 
 # global variables not to be changed by user
 :global GlobalFunctionsReady false;

news-and-changes.rsc

@@ -44,6 +44,7 @@
         [ $IfThenElse ($Resource->"free-hdd-space" > 4000000) ("(Your " . $Resource->"board-name" . " does not suffer this issue.) ") ] ] . \
         "Huge configuration and lots of scripts give an extra risk. Take care!");
   119="Added support for IPv6 to script 'fw-addr-lists'.";
+  120="Implemented a workaround in 'backup-cloud'. Now script should no longer just crash, but send notification with error.";
 };
 
 # Migration steps to be applied on script updates