notify: fix notify.sh to work with server side; adjust text

backup.py

@@ -320,31 +320,51 @@ def main(argv: list[str]):
     warnings = sum(1 for (letter, msg) in backup.logs if letter == 'W')
     errors = sum(1 for (letter, msg) in backup.logs if letter == 'E')
 
+    def plural(num: int, word: str) -> str:
+        suffix = "" if num == 1 else "s"
+        return f"{num} {word}{suffix}"
+
+    warnmsg = plural(warnings, "warning") if warnings else None
+    errmsg = plural(errors, "error") if errors else None
+
     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 warnmsg:
+            backup.log('W', f"reported {warnmsg}", bold=True)
         if errors:
-            backup.log('E', f"reported {errors} errors", bold=True)
+            backup.log('E', f"reported {errmsg}", 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:" ]
+            # Show all of our warnings and errors.  Use a ">" prefix
+            # so warnings and errors get highlighted by the mail reader.
+            body = [ "Logs from backup.py:" ]
             for (letter, msg) in backup.logs:
-                body.append(f"{letter}: {msg}")
+                if letter == "E" or letter == "W":
+                    prefix = ">"
+                else:
+                    prefix = " "
+                body.append(f"{prefix}{letter}: {msg}")
             body_text = "\n".join(body).encode()
 
             # Followed by borg output
-            body_text += b"\nBorg output:\n" + b"".join(captured_output)
+            body_text += b"\n\nBorg output:\n" + b"".join(captured_output)
+
+            # Subject summary
+            if errmsg and warnmsg:
+                summary = f"{errmsg}, {warnmsg}"
+            elif errors:
+                summary = errmsg
+            else:
+                summary = warnmsg
 
             # Call notify.sh
-            res = subprocess.run([args.notify, email], input=body_text)
+            res = subprocess.run([args.notify, summary, email], input=body_text)
             if res.returncode != 0:
                 backup.log('E', f"failed to send notification")
                 errors += 1

notify.sh

@@ -12,8 +12,15 @@ if tty -s ; then
     exit 1
 fi
 
-ssh \
-    -F "$SSH/config" \
-    -i "$SSH/id_ecdsa_notify" \
-    "$BACKUP_USER@$BACKUP_HOST" \
-    borg/notify.sh "$HOSTNAME" "$1"
+SUMMARY="$1"
+EMAIL="$2"
+
+# Remote notify.sh wants subject as first line, not as an argument,
+# since it's a bit messy to pass complex strings through ssh command
+# lines.
+( echo "backup $HOSTNAME: $SUMMARY" ; cat ) | \
+    ssh \
+	-F "$SSH/config" \
+	-i "$SSH/id_ecdsa_notify" \
+	"$BACKUP_USER@$BACKUP_HOST" \
+	borg/notify.sh "$EMAIL"