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FabledSteward/steward/hosts/service.py
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bvandeusenandClaude Opus 5.5 bfe3618e88
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feat(hosts): the Hosts list labels its figures and says how long; SLA tab gone; one place to add a host (#5279–#5283)
Hosts list:
- CPU and Memory are their own labelled columns (#5279); a silent
  agent's last readings are greyed, and Status says "agent silent for 7m".
- One uptime figure, 30 days, with 24h and 7d on hover. The SLA tab
  (/hosts/uptime) repeated it and is removed (#5280; one home per fact).
- Status is a word with how long ("Down for 12m"); host_status now carries
  down_since. Edit and Delete live on the host's page only (#5281).
- Figures are right-aligned with tabular digits (.table .num), not a
  monospace face.

Agent fleet (#5282): its add-host form is gone, so hosts are added only on
Hosts -> Add host. That form was also the only way to get a token for a
manual curl install, so that moves to the host's Agent card as "Install
manually" (POST /fleet/<host_id>/register), shown on the fleet page as
before. "Delete" there reads "Unregister".

Add host (#5283): laid out like the add-monitor form; a name clash comes
back inline with what was typed instead of a bare text 400; the address
is optional, as the host page already allowed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-07 17:12:17 -04:00

256 lines
11 KiB
Python

"""Host queries shared by the Hosts pages, dashboard widgets and MCP tools.
Every function takes an open session and returns plain data; none reads
Quart's request context, so the web routes and the /mcp tools (which run
outside Quart's pipeline) call the same code.
"""
from __future__ import annotations
from datetime import datetime, timedelta, timezone
from sqlalchemy import and_, case, func, select
from steward.core.status import _heartbeat_title, _last_n_results, _uptime_by_monitor
from steward.models.hosts import Host
from steward.models.monitors import Monitor, MonitorResult
# Host-level agent metrics read for the at-a-glance views (plus the root
# mount's disk_used_pct, read from the "<host>:/" sub-resource).
AGENT_GLANCE_METRICS = ("cpu_pct", "mem_used_pct", "disk_used_pct", "disk_used_pct_worst", "load_1m")
async def check_name_free(db, name: str, exclude_id: str | None = None) -> None:
"""ValueError when another host already has this name, or it is blank.
Agent metrics, container metrics and the alert rules on them go by the
host's name, so two hosts sharing one would share one history.
"""
if not name:
raise ValueError("a host needs a name.")
q = select(Host.id).where(Host.name == name)
if exclude_id:
q = q.where(Host.id != exclude_id)
if (await db.execute(q.limit(1))).first():
raise ValueError(f"another host is already named {name!r}; pick a different name.")
def agent_stale_after_seconds(config) -> int:
"""The host_agent plugin's freshness window from app config (default 180s)."""
return int(((config.get("PLUGINS") or {}).get("host_agent") or {})
.get("stale_after_seconds", 180))
async def compute_uptime(db) -> dict[str, dict]:
"""Per-host uptime % for 24h/7d/30d, aggregated over the host's monitors.
Returns {host_id: {"24h": float|None, "7d": float|None, "30d": float|None}}.
"""
now = datetime.now(timezone.utc)
cutoff_30d = now - timedelta(days=30)
cutoff_7d = now - timedelta(days=7)
cutoff_24h = now - timedelta(hours=24)
result = await db.execute(
select(
Monitor.host_id,
func.count(MonitorResult.id).label("total_30d"),
func.sum(case((MonitorResult.is_up.is_(True), 1), else_=0)).label("up_30d"),
func.sum(case((MonitorResult.checked_at >= cutoff_7d, 1), else_=0)).label("total_7d"),
func.sum(case(
(and_(MonitorResult.checked_at >= cutoff_7d, MonitorResult.is_up.is_(True)), 1),
else_=0,
)).label("up_7d"),
func.sum(case((MonitorResult.checked_at >= cutoff_24h, 1), else_=0)).label("total_24h"),
func.sum(case(
(and_(MonitorResult.checked_at >= cutoff_24h, MonitorResult.is_up.is_(True)), 1),
else_=0,
)).label("up_24h"),
)
.join(Monitor, Monitor.id == MonitorResult.monitor_id)
.where(Monitor.host_id.isnot(None), MonitorResult.checked_at >= cutoff_30d)
.group_by(Monitor.host_id)
)
def _pct(up, total):
return round(float(up) / float(total) * 100, 2) if total else None
stats: dict[str, dict] = {}
for row in result:
stats[row.host_id] = {
"24h": _pct(row.up_24h, row.total_24h),
"7d": _pct(row.up_7d, row.total_7d),
"30d": _pct(row.up_30d, row.total_30d),
}
return stats
async def host_status(db, host_ids: list[str]) -> dict[str, dict]:
"""Per-host status rollup from the latest result of each linked monitor.
{host_id: {"state": "up"|"down"|"pending", "latency_ms": float|None,
"count": int, "down_since": datetime|None}}. State is down if
ANY linked monitor's latest result is down (worst-case), up if at least
one is up, else pending. down_since is when the longest-down of its down
monitors went down.
"""
if not host_ids:
return {}
monitors = (await db.execute(
select(Monitor.id, Monitor.host_id)
.where(Monitor.host_id.in_(host_ids), Monitor.enabled.is_(True))
)).all()
latest = await _last_n_results(db, [m.id for m in monitors], n=1)
rows = [(latest[mid][-1], host_id, mid) for mid, host_id in monitors if latest.get(mid)]
out: dict[str, dict] = {}
down: dict[str, list[str]] = {}
for res, host_id, mid in rows:
d = out.setdefault(host_id, {"state": "pending", "latency_ms": None, "count": 0,
"down_since": None})
d["count"] += 1
if not res.is_up:
d["state"] = "down"
down.setdefault(host_id, []).append(mid)
elif d["state"] != "down":
d["state"] = "up"
if res.is_up and res.response_ms is not None:
d["latency_ms"] = (res.response_ms if d["latency_ms"] is None
else min(d["latency_ms"], res.response_ms))
if down:
from steward.monitors.service import down_since
for host_id, mids in down.items():
starts = [t for t in [await down_since(db, mid) for mid in mids] if t]
out[host_id]["down_since"] = min(starts) if starts else None
return out
def host_rank(status: dict | None, agent: dict | None) -> int:
"""Where a host sorts in the Hosts list: a down monitor first, then an
agent gone quiet, then monitors not yet checked, then the healthy; a host
with neither monitors nor agent last."""
if status and status["state"] == "down":
return 0
if agent and not agent.get("fresh"):
return 1
if status and status["state"] == "pending":
return 2
if status or agent:
return 3
return 4
async def host_monitors(db, host_id: str) -> list[dict]:
"""Display rows for the monitors linked to one host (host hub section)."""
monitors = (await db.execute(
select(Monitor).where(Monitor.host_id == host_id).order_by(Monitor.name)
)).scalars().all()
ids = [m.id for m in monitors]
recent = await _last_n_results(db, ids)
uptime = await _uptime_by_monitor(db, ids)
data = []
from steward.monitors.service import down_reason, down_since
for m in monitors:
mrows = recent.get(m.id, [])
latest = mrows[-1] if mrows else None
state = ("paused" if not m.enabled else "pending" if latest is None
else "up" if latest.is_up else "down")
data.append({
"monitor": m, "latest": latest, "state": state,
"heartbeat": [{"state": "up" if r.is_up else "down",
"title": _heartbeat_title(m.type, r)} for r in mrows],
"uptime_pct": uptime.get(m.id, {}).get("24h"),
"down_since": await down_since(db, m.id) if state == "down" else None,
"down_reason": down_reason(latest) if state == "down" else None,
})
# Problems first: down, then not yet checked, then up, paused last.
order = {"down": 0, "pending": 1, "up": 2, "paused": 3}
return sorted(data, key=lambda d: (order[d["state"]], d["monitor"].name.lower()))
async def agent_overview_by_host(
db, host_names: list[str], stale_after_seconds: int = 180,
) -> dict[str, dict]:
"""Per-host agent glance (cpu/mem/disk/load + freshness) from plugin_metric_latest.
{host_name: {cpu_pct, mem_used_pct, disk_used_pct_worst, disk_root, load_1m,
cores, load_per_core, last_at, fresh}} for each host with any
agent samples. Cores are counted from the per-core CPU sub-resources
("<host>:core<N>"), as on the host page; load_per_core is load_1m as a %
of them, the figure Settings → Thresholds grades "load" by.
Core-safe (no host_agent import). Freshness compares the latest host-level
sample against the host_agent plugin's stale window (stale_after_seconds;
callers pass agent_stale_after_seconds(app.config)). A host whose agent has
gone quiet keeps its last values with fresh=False (#5208).
"""
from steward.core.metric_series import latest_by_resource
if not host_names:
return {}
now = datetime.now(timezone.utc)
stale_after = int(stale_after_seconds)
latest = await latest_by_resource(
db, "host_agent", list(host_names) + [h + ":/" for h in host_names],
set(AGENT_GLANCE_METRICS) | {"disk_used_pct"})
from steward.models.metrics import PluginMetricLatest
cores: dict[str, int] = {}
for res in (await db.execute(
select(PluginMetricLatest.resource_name).where(
PluginMetricLatest.source_module == "host_agent",
PluginMetricLatest.metric_name == "cpu_pct",
PluginMetricLatest.resource_name.like("%:core%"))
)).scalars():
host = res.rsplit(":core", 1)[0]
cores[host] = cores.get(host, 0) + 1
out: dict[str, dict] = {}
for name in host_names:
own = {m: r for m, r in latest.get(name, {}).items() if m in AGENT_GLANCE_METRICS}
root = latest.get(name + ":/", {}).get("disk_used_pct")
if not own and root is None:
continue
d = {m: r.value for m, r in own.items()}
if root is not None:
d["disk_root"] = root.value
ts = max((r.recorded_at for r in own.values()), default=None)
d["last_at"] = ts
d["fresh"] = bool(ts and (now - ts).total_seconds() <= stale_after)
d["cores"] = cores.get(name)
load = d.get("load_1m")
d["load_per_core"] = round(load / d["cores"] * 100) if (load is not None and d["cores"]) else None
out[name] = d
return out
GLANCE_ORDER = {"down": 0, "crit": 1, "stale": 2, "warn": 3, "up": 4, "unknown": 5}
def host_glance(hosts, status: dict, agent: dict, thresholds: dict) -> list[dict]:
"""The Hosts — Overview rows, worst first (#5251).
Each is {host, state, worst, agent}. State is "down" when a linked monitor
is down, "stale" when the agent has stopped reporting, else the grade of
the reading furthest past its cutoff ("crit" / "warn": CPU, memory, disk /
or load per core, against Settings → Thresholds), else "up"; "unknown" for
a host with neither monitors nor agent. `worst` is (label, value, grade)
or None, from formatting.worst_reading."""
from steward.core.formatting import worst_reading
rows = []
for h in hosts:
st, a = status.get(h.id), agent.get(h.name)
worst = None
if a and a.get("fresh"):
worst = worst_reading((
("CPU", a.get("cpu_pct"), "cpu"), ("Memory", a.get("mem_used_pct"), "mem"),
("Disk /", a.get("disk_root"), "disk"), ("Load", a.get("load_per_core"), "load")),
thresholds)
if st and st["state"] == "down":
state = "down"
elif a and not a.get("fresh"):
state = "stale"
elif worst:
state = worst[2]
elif st or a:
state = "up"
else:
state = "unknown"
rows.append({"host": h, "state": state, "worst": worst, "agent": a or {}})
return sorted(rows, key=lambda r: (GLANCE_ORDER[r["state"]], r["host"].name.lower()))