Show netx database used size on the workbench storage gauge.

Co-authored-by: Cursor <cursoragent@cursor.com>

netx_api/db_storage_metrics.py

@@ -0,0 +1,65 @@
+"""PostgreSQL database size for workbench (used bytes only)."""
+
+from __future__ import annotations
+
+import threading
+import time
+from typing import Any
+
+from sqlalchemy import text
+
+from .config import settings
+
+_CACHE_LOCK = threading.Lock()
+_CACHED: dict[str, Any] | None = None
+_CACHED_AT = 0.0
+_CACHE_TTL_SEC = 30.0
+
+
+def _open_session():
+    """Indirection so tests can patch without importing the full engine."""
+    from .db import SessionLocal
+
+    return SessionLocal()
+
+
+def _collect_uncached() -> dict[str, Any]:
+    url = str(settings.database_url or "")
+    out: dict[str, Any] = {
+        "used_bytes": 0,
+        "source": "none",
+    }
+    if url.startswith("sqlite"):
+        out["source"] = "sqlite"
+        out["error"] = "not_applicable"
+        return out
+
+    try:
+        with _open_session() as db:
+            row = db.execute(
+                text(
+                    "SELECT current_database() AS db_name, "
+                    "pg_database_size(current_database())::bigint AS used_bytes"
+                )
+            ).mappings().one()
+            out["db_name"] = str(row["db_name"] or "")
+            out["used_bytes"] = int(row["used_bytes"] or 0)
+            out["source"] = "pg_database_size"
+    except Exception as exc:  # noqa: BLE001
+        out["source"] = "error"
+        out["error"] = str(exc)[:200]
+    return out
+
+
+def collect_db_storage_metrics() -> dict[str, Any]:
+    """Return PG used-size dict; never raises. Cached ~30s."""
+    global _CACHED, _CACHED_AT
+    now = time.monotonic()
+    with _CACHE_LOCK:
+        if _CACHED is not None and (now - _CACHED_AT) < _CACHE_TTL_SEC:
+            return dict(_CACHED)
+    out = _collect_uncached()
+    with _CACHE_LOCK:
+        _CACHED = dict(out)
+        _CACHED_AT = time.monotonic()
+    return out

netx_api/metrics_router.py

@@ -12,6 +12,7 @@ from .audit_async import audit_queue_status
 from .cli_budget import cli_budget_status
 from .config import settings
 from .db import db_pool_status
+from .db_storage_metrics import collect_db_storage_metrics
 from .host_metrics import collect_host_metrics
 from .oclaw_alarm_forwarder import forwarder_status
 
@@ -26,6 +27,7 @@ def collect_runtime_metrics() -> dict[str, Any]:
         "pid": os.getpid(),
         "thread_count": threading.active_count(),
         "db_pool": db_pool_status(),
+        "db_storage": collect_db_storage_metrics(),
         "cli_budget": cli_budget_status(),
         "audit_queue": audit_queue_status(),
         "oclaw_forwarder": forwarder_status(),
@@ -142,6 +144,9 @@ def _prom_lines(metrics: dict[str, Any]) -> str:
         lines.append(f'netx_host_mem_used_bytes {host["mem_used_bytes"]}')
     if host.get("mem_total_bytes") is not None:
         lines.append(f'netx_host_mem_total_bytes {host["mem_total_bytes"]}')
+    storage = metrics.get("db_storage") or {}
+    if storage.get("used_bytes") is not None:
+        lines.append(f'netx_db_storage_used_bytes {int(storage.get("used_bytes") or 0)}')
     lines.append("")
     return "\n".join(lines)