feat: ping/DNS status and latency in hosts list and dashboard summary

fablednetmon/dashboard/routes.py

@@ -1,6 +1,10 @@
-from quart import Blueprint, render_template
+from __future__ import annotations
+from quart import Blueprint, render_template, current_app
+from sqlalchemy import select, func
 from fablednetmon.auth.middleware import require_role
 from fablednetmon.models.users import UserRole
+from fablednetmon.models.hosts import Host
+from fablednetmon.models.monitors import PingResult, DnsResult
 
 dashboard_bp = Blueprint("dashboard", __name__)
 
@@ -8,4 +12,51 @@ dashboard_bp = Blueprint("dashboard", __name__)
 @dashboard_bp.get("/")
 @require_role(UserRole.viewer)
 async def index():
-    return await render_template("dashboard/index.html")
+    async with current_app.db_sessionmaker() as db:
+        # Latest ping per host
+        latest_ping_subq = (
+            select(PingResult.host_id, func.max(PingResult.probed_at).label("max_at"))
+            .group_by(PingResult.host_id)
+            .subquery()
+        )
+        pr = await db.execute(
+            select(PingResult).join(
+                latest_ping_subq,
+                (PingResult.host_id == latest_ping_subq.c.host_id)
+                & (PingResult.probed_at == latest_ping_subq.c.max_at),
+            )
+        )
+        latest_pings = list(pr.scalars())
+        ping_up = sum(1 for p in latest_pings if p.status.value == "up")
+        ping_down = sum(1 for p in latest_pings if p.status.value == "down")
+
+        # Latest DNS per host
+        latest_dns_subq = (
+            select(DnsResult.host_id, func.max(DnsResult.resolved_at).label("max_at"))
+            .group_by(DnsResult.host_id)
+            .subquery()
+        )
+        dr = await db.execute(
+            select(DnsResult).join(
+                latest_dns_subq,
+                (DnsResult.host_id == latest_dns_subq.c.host_id)
+                & (DnsResult.resolved_at == latest_dns_subq.c.max_at),
+            )
+        )
+        latest_dns = list(dr.scalars())
+        dns_ok = sum(1 for d in latest_dns if d.status.value == "resolved")
+        dns_fail = sum(1 for d in latest_dns if d.status.value != "resolved")
+
+        total_hosts = (await db.execute(select(func.count()).select_from(Host))).scalar()
+
+    poll_interval = current_app.config.get("MONITORS_POLL_INTERVAL", 60)
+
+    return await render_template(
+        "dashboard/index.html",
+        ping_up=ping_up,
+        ping_down=ping_down,
+        dns_ok=dns_ok,
+        dns_fail=dns_fail,
+        total_hosts=total_hosts,
+        poll_interval=poll_interval,
+    )