add custom actions configuration to enable invoking scripts other commands on script start and end. Defined by $CustomAction* config variables.

backup.ps1

@@ -546,6 +546,11 @@ function Invoke-Main {
         exit 1
     }
 
+    # custom start action
+    if($null -ne $CustomActionStart) {
+        Invoke-Expression $CustomActionStart
+    }
+
     $error_count = 0
     $backup_success = $false
     $maintenance_success = $false
@@ -671,6 +676,20 @@ function Invoke-Main {
         }
     }
 
+    # custom end actions
+    if((-not $backup_success) -or ($maintenance_needed -and -not $maintenance_success)) {
+        # call the custom error action if backup failed and/or maintenance was needed and failed
+        if($null -ne $CustomActionEndError) {
+            Invoke-Expression $CustomActionEndError
+        }
+    }
+    else {
+        # call custom success action if backup & maintenance were successful
+        if($null -ne $CustomActionEndSuccess) {
+            Invoke-Expression $CustomActionEndSuccess
+        }        
+    }
+
     # Save state to file
     Set-BackupState
 

config.ps1

@@ -40,4 +40,13 @@ $SnapshotMaintenanceDays = 30
 $SnapshotDeepMaintenanceDays = 90
 
 # restic.exe self update configuration
-$SelfUpdateEnabled = $true
+$SelfUpdateEnabled = $true
+
+# (optional) custom actions 
+# Define commands to pass to Invoke-Expression at script start and end
+# note: Errors will only be reported if the script does not eventually succeed. Errors 
+#       from unsuccessful attempts to backup or maintain the repository will not result
+#       in the custom error action being called unless all attempts failed. 
+$CustomActionStart = $null
+$CustomActionEndError = $null
+$CustomActionEndSuccess = $null