feat(metrics): add query_instance_metrics read aggregation

backend/app/services/metrics_history.py

@@ -91,3 +91,66 @@ def aggregate_series(rows, from_ts, bucket, fields):
             point[f] = (sum(vals) / len(vals)) if vals else None
         out.append(point)
     return out
+
+
+from datetime import timezone as _tz
+
+_AGG_FIELDS = ["cpu", "mem", "maxmem", "netin", "netout",
+               "diskread", "diskwrite", "diskpct", "iops_read", "iops_write"]
+
+
+def _to_ts(dt):
+    if dt.tzinfo is None:
+        dt = dt.replace(tzinfo=_tz.utc)
+    return int(dt.timestamp())
+
+
+def query_instance_metrics(db, server_id, vmid, from_ts, to_ts, nic="all"):
+    from ..models import InstanceMetric, InstanceNicMetric
+    from datetime import datetime
+
+    start = datetime.fromtimestamp(from_ts, tz=_tz.utc)
+    end = datetime.fromtimestamp(to_ts, tz=_tz.utc)
+
+    base = (db.query(InstanceMetric)
+              .filter(InstanceMetric.server_id == server_id,
+                      InstanceMetric.vmid == vmid,
+                      InstanceMetric.ts >= start, InstanceMetric.ts <= end)
+              .order_by(InstanceMetric.ts.asc()).all())
+
+    # Distinct NICs seen in the window (for the selector).
+    nic_rows = (db.query(InstanceNicMetric)
+                  .filter(InstanceNicMetric.server_id == server_id,
+                          InstanceNicMetric.vmid == vmid,
+                          InstanceNicMetric.ts >= start, InstanceNicMetric.ts <= end)
+                  .order_by(InstanceNicMetric.ts.asc()).all())
+    nics = sorted({r.dev for r in nic_rows})
+
+    # Optional per-NIC override of net rates, keyed by exact timestamp.
+    nic_by_ts: dict[int, tuple] = {}
+    if nic != "all":
+        for r in nic_rows:
+            if r.dev == nic:
+                nic_by_ts[_to_ts(r.ts)] = (r.in_rate, r.out_rate)
+
+    rows = []
+    for m in base:
+        ts = _to_ts(m.ts)
+        netin, netout = m.netin_rate, m.netout_rate
+        if nic != "all":
+            ov = nic_by_ts.get(ts)
+            netin, netout = (ov if ov else (None, None))
+        diskpct = (m.disk_used / m.disk_total * 100.0) if (m.disk_total or 0) > 0 else None
+        rows.append({
+            "time": ts,
+            "cpu": (m.cpu * 100.0) if m.cpu is not None else None,
+            "mem": m.mem, "maxmem": m.maxmem,
+            "netin": netin, "netout": netout,
+            "diskread": m.diskread_rate, "diskwrite": m.diskwrite_rate,
+            "diskpct": diskpct,
+            "iops_read": m.iops_read, "iops_write": m.iops_write,
+        })
+
+    bucket = pick_bucket_seconds(from_ts, to_ts)
+    data = aggregate_series(rows, from_ts, bucket, _AGG_FIELDS)
+    return {"data": data, "from": from_ts, "to": to_ts, "meta": {"nics": nics}}

backend/tests/test_metrics_query.py

@@ -0,0 +1,45 @@
+# backend/tests/test_metrics_query.py
+from datetime import datetime, timezone
+from app.services.metrics_history import query_instance_metrics
+
+
+def _row(db, InstanceMetric, ts, **kw):
+    db.add(InstanceMetric(server_id=1, vmid=114, vm_type="qemu",
+                          ts=datetime.fromtimestamp(ts, tz=timezone.utc), **kw))
+
+
+def test_query_aggregate_all_nic(db_session):
+    from app.models import InstanceMetric
+    _row(db_session, InstanceMetric, 1000, cpu=0.10, mem=100, maxmem=200,
+         disk_used=10, disk_total=40, netin_rate=1.0, netout_rate=2.0,
+         diskread_rate=0.0, diskwrite_rate=0.0, iops_read=5.0, iops_write=1.0)
+    _row(db_session, InstanceMetric, 1005, cpu=0.30, mem=140, maxmem=200,
+         disk_used=20, disk_total=40, netin_rate=3.0, netout_rate=4.0,
+         diskread_rate=0.0, diskwrite_rate=0.0, iops_read=7.0, iops_write=3.0)
+    db_session.commit()
+    out = query_instance_metrics(db_session, 1, 114, from_ts=1000, to_ts=1010, nic="all")
+    assert out["from"] == 1000 and out["to"] == 1010
+    pt = out["data"][0]
+    assert pt["cpu"] == 20.0          # avg(10%,30%)
+    assert pt["netin"] == 2.0         # avg(1,3)
+    assert pt["diskpct"] == 37.5      # avg(25%,50%)
+    assert pt["iops_read"] == 6.0
+
+
+def test_query_specific_nic_overrides_net(db_session):
+    from app.models import InstanceMetric, InstanceNicMetric
+    _row(db_session, InstanceMetric, 1000, cpu=0.0, mem=0, maxmem=1,
+         disk_used=0, disk_total=1, netin_rate=99.0, netout_rate=99.0,
+         diskread_rate=0.0, diskwrite_rate=0.0, iops_read=0.0, iops_write=0.0)
+    db_session.add(InstanceNicMetric(server_id=1, vmid=114,
+        ts=datetime.fromtimestamp(1000, tz=timezone.utc), dev="tap114i0",
+        in_rate=7.0, out_rate=8.0))
+    db_session.commit()
+    out = query_instance_metrics(db_session, 1, 114, 1000, 1010, nic="tap114i0")
+    assert out["meta"]["nics"] == ["tap114i0"]
+    assert out["data"][0]["netin"] == 7.0 and out["data"][0]["netout"] == 8.0
+
+
+def test_query_empty(db_session):
+    out = query_instance_metrics(db_session, 1, 999, 0, 10, nic="all")
+    assert out["data"] == [] and out["meta"]["nics"] == []