18901: FIX Reenable rrdcached daemon pausing during online backups

SUP-27728

Regression introduced in "Enable bandit check B108 (hardcoded_tmp_directory)" in the change with ID:
I0102461e41a84caa9726bb3e743f82caf9c8d3d8

Change-Id: Ib77fcfaf0d0a3fe98332ac0b6fefc22bbc305937

Author: SoloJacobs

.werks/18901.md

@@ -0,0 +1,19 @@
+[//]: # (werk v3)
+# Reenable rrdcached daemon pausing during online backups
+
+key        | value
+---------- | ---
+date       | 2026-04-09T08:57:01.899842+00:00
+version    | 2.5.0b4
+class      | fix
+edition    | community
+component  | omd
+level      | 1
+compatible | yes
+
+During online backups, the backup process is supposed to pause the rrdcached
+daemon while copying RRD files. Due to an incorrect socket path introduced in
+2.3.0b1, this pausing was not working, and the backup script logged an error
+accordingly.
+
+This has been fixed by correcting the socket path.

omd/packages/omd/omdlib/backup.py

@@ -157,7 +157,7 @@ def accepted_files(tarinfo: tarfile.TarInfo) -> bool:
             for glob_pattern in excludes
         )
 
-    with _RRDSocket(site_is_stopped, site_name, verbose) as rrd_socket:
+    with _RRDSocket(site_is_stopped, site_home, site_name, verbose) as rrd_socket:
         # Add the version symlink as first file to be able to
         # check a) the sitename and b) the version before reading
         # the whole tar archive. Important for streaming.
@@ -235,8 +235,8 @@ def get_exclude_patterns(options: BackupExclusions) -> list[str]:
 
 
 class _RRDSocket(contextlib.AbstractContextManager["_RRDSocket"]):
-    def __init__(self, site_stopped: bool, site_name: str, verbose: bool) -> None:
-        self._rrdcached_socket_path = str(Path("site_dir") / "tmp/run/rrdcached.sock")
+    def __init__(self, site_stopped: bool, site_home: str, site_name: str, verbose: bool) -> None:
+        self._rrdcached_socket_path = Path(site_home, "tmp/run/rrdcached.sock")  # nosec B108 # not system /tmp; site_home is owned by the site user
         self._site_requires_suspension = not site_stopped and os.path.exists(
             self._rrdcached_socket_path
         )
@@ -292,7 +292,7 @@ def _send_rrdcached_command(self, cmd: str) -> None:
         if self._sock is None:
             sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
             try:
-                sock.connect(self._rrdcached_socket_path)
+                sock.connect(os.fspath(self._rrdcached_socket_path))
             except OSError as e:
                 if self._verbose:
                     sys.stdout.write("skipping rrdcached command (%s)\n" % e)