backup: print final results and run notification script on error

backup.py

@@ -229,6 +229,7 @@ def main(argv: list[str]):
     def humansize(string):
         return humanfriendly.parse_size(string)
 
+    # Parse args
     parser = argparse.ArgumentParser(
         prog=argv[0],
         description="Back up the local system using borg",
@@ -239,6 +240,8 @@ def main(argv: list[str]):
                         help="Config file", default=str(base / "config.yaml"))
     parser.add_argument('-b', '--borg',
                         help="Borg command", default=str(base / "borg.sh"))
+    parser.add_argument('-N', '--notify',
+                        help="Notify command", default=str(base / "notify.sh"))
     parser.add_argument('-n', '--dry-run', action="store_true",
                         help="Just print log output, don't run borg")
     parser.add_argument('-d', '--debug', action="store_true",
@@ -313,6 +316,42 @@ def main(argv: list[str]):
         elif ret != 0:
             backup.log('E', f"borg exited with return code {ret}")
 
+    # See if we had any errors
+    warnings = sum(1 for (letter, msg) in backup.logs if letter == 'W')
+    errors = sum(1 for (letter, msg) in backup.logs if letter == 'E')
+
+    if not warnings and not errors:
+        backup.log('I', f"backup successful", bold=True)
+
+    else:
+        if warnings:
+            backup.log('W', f"reported {warnings} warnings", bold=True)
+        if errors:
+            backup.log('E', f"reported {errors} errors", bold=True)
+
+        # Send a notification of errors
+        email = backup.config.notify_email
+        if email and not args.dry_run:
+            backup.log('I', f"sending error notification to {email}")
+
+            # Show all of our warnings and errors
+            body = [ "Backup reported the following warnings and errors:" ]
+            for (letter, msg) in backup.logs:
+                body.append(f"{letter}: {msg}")
+            body_text = "\n".join(body).encode()
+
+            # Followed by borg output
+            body_text += b"\nBorg output:\n" + b"".join(captured_output)
+
+            # Call notify.sh
+            res = subprocess.run([args.notify, email], input=body_text)
+            if res.returncode != 0:
+                backup.log('E', f"failed to send notification")
+                errors += 1
+
+    # Exit with an error code if we had any errors
+    if errors:
+        return 1
     return 0
 
 if __name__ == "__main__":