fix(prometheus, syslog): a target or pattern pauses with a Pause/Resume button, not an "on" tick box in its form (#6419)

Monitors, schedules and maintenance plans already pause with a
Pause/Resume button and say "Paused" where they're listed. Prometheus
targets and syslog patterns only had a tick box inside the edit form,
so a target refused by its endpoint couldn't be stopped from its page.

- Both get a Pause/Resume button (target page and list; patterns list)
  posting to /toggle, recorded in the audit log, and a Paused badge.
- The forms lose the tick box. A new one starts running; an edit keeps
  whether it is paused.
- A target's "off" state is now "paused", in its pages and MCP tools.
  A resumed target reads "not scraped yet" until its next scrape, and its
  counter rates start over.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugins/prometheus/mcp_tools.py

@@ -19,7 +19,7 @@ from .models import PrometheusTarget
 from .routes import group_series
 from .service import OWN_METRICS, SOURCE, target_state
 
-REACHES = ("down", "stale", "pending", "up", "off")
+REACHES = ("down", "stale", "pending", "up", "paused")
 _ORDER = {r: i for i, r in enumerate(REACHES)}
 
 
@@ -37,7 +37,7 @@ async def list_prometheus_targets() -> dict:
     """The /metrics endpoints Steward scrapes, not answering first.
 
     `reach`: "down" (the last scrape failed; `says` is why), "stale" (not
-    scraped recently), "pending", "up" or "off". `series_kept` /
+    scraped recently), "pending", "up" or "paused". `series_kept` /
     `series_dropped` count the newest scrape's series the keep/drop patterns
     let through or left out; `series_capped` those past `series_cap`, which
     were not stored. get_prometheus_target lists a target's series;
@@ -94,7 +94,7 @@ async def get_prometheus_target(target: str, search: str = "", limit: int = 100)
 
 
 def target_findings(views: list[dict]) -> list[dict]:
-    """A target whose last scrape failed. Stale and off are the plugin or
+    """A target whose last scrape failed. Stale and paused are the plugin or
     the admin's choice, not the endpoint, so they are left out."""
     return [finding("warning", "prometheus_target_down", v["name"],
                     f"Prometheus target {v['name']} isn't answering: {v['says']}",

plugins/prometheus/routes.py

@@ -25,7 +25,7 @@ from .service import (OWN_METRICS, SOURCE, FormError, fold_states, form_values,
 
 prometheus_bp = Blueprint("prometheus", __name__, template_folder="templates")
 
-_REACH_ORDER = {"down": 0, "stale": 1, "pending": 2, "up": 3, "off": 4}
+_REACH_ORDER = {"down": 0, "stale": 1, "pending": 2, "up": 3, "paused": 4}
 
 
 def _actor() -> tuple[str | None, str]:
@@ -40,7 +40,8 @@ def view(target: PrometheusTarget, own: dict, now: datetime) -> dict:
     """What a page says about a target: its state in words and the numbers
     from its newest scrape."""
     state = target_state(target, now)
-    return {"id": target.id, "name": target.name, "url": target.url, "reach": state.reach,
+    return {"id": target.id, "name": target.name, "url": target.url, "enabled": target.enabled,
+            "reach": state.reach,
             "says": state.says, "scraped_at": target.last_scraped_at, "ok_at": target.last_ok_at,
             "interval": target.interval_seconds, "kept": target.last_kept,
             "dropped": target.last_dropped, "capped": target.last_capped, "cap": target.series_cap,
@@ -79,8 +80,7 @@ def _typed(form, target: PrometheusTarget | None = None) -> dict:
     return {"name": form.get("name", ""), "url": form.get("url", ""),
             "interval_seconds": form.get("interval_seconds", ""), "series_cap": form.get("series_cap", ""),
             "keep": form.get("keep", ""), "drop": form.get("drop", ""),
-            "verify_tls": bool(form.get("verify_tls")), "enabled": bool(form.get("enabled")),
-            "has_token": bool(target and target.token)}
+            "verify_tls": bool(form.get("verify_tls")), "has_token": bool(target and target.token)}
 
 
 async def _name_taken(db, name: str, other_than: str | None = None) -> bool:
@@ -176,6 +176,27 @@ async def save_target(target_id: str):
     return redirect(f"/plugins/prometheus/targets/{target_id}")
 
 
+@prometheus_bp.post("/targets/<target_id>/toggle")
+@require_role(UserRole.admin)
+async def toggle_target(target_id: str):
+    """Pause a target, or resume a paused one, from its page or the list."""
+    async with current_app.db_sessionmaker() as db:
+        async with db.begin():
+            target = await _target_or_404(db, target_id)
+            target.enabled = not target.enabled
+            if target.enabled:
+                # Resumed: it reads "not scraped yet" until the next scrape,
+                # rather than stale from before the pause.
+                target.last_scraped_at = target.last_error = None
+            enabled, name = target.enabled, target.name
+    # A rate needs two readings in a row; one from before the pause isn't one.
+    from . import scheduler
+    scheduler.RATES.forget(target_id)
+    await log_audit(current_app, *_actor(), "prometheus.target_resumed" if enabled else "prometheus.target_paused",
+                    entity_type="prometheus_target", entity_id=target_id, detail={"name": name})
+    return redirect(request.referrer or f"/plugins/prometheus/targets/{target_id}")
+
+
 @prometheus_bp.post("/targets/<target_id>/delete")
 @require_role(UserRole.admin)
 async def delete_target(target_id: str):

plugins/prometheus/service.py

@@ -197,11 +197,10 @@ def form_values(target: PrometheusTarget | None) -> dict:
     """The form's fields for an existing target. The token is never sent back
     to the browser; a blank token field on save keeps the stored one."""
     if target is None:
-        return {"interval_seconds": 60, "series_cap": 1000, "verify_tls": True, "enabled": True,
-                "keep": "", "drop": ""}
+        return {"interval_seconds": 60, "series_cap": 1000, "verify_tls": True, "keep": "", "drop": ""}
     return {"name": target.name, "url": target.url, "interval_seconds": target.interval_seconds,
             "series_cap": target.series_cap, "verify_tls": target.verify_tls,
-            "enabled": target.enabled, "keep": "\n".join(target.keep or []),
+            "keep": "\n".join(target.keep or []),
             "drop": "\n".join(target.drop or []), "has_token": bool(target.token)}
 
 
@@ -217,7 +216,8 @@ def _bounded(form, key: str, default: int, low: int, high: int, says: str) -> in
 
 def parse_form(form, existing: PrometheusTarget | None = None) -> dict:
     """The submitted form as the columns to store, the token encrypted.
-    Raises FormError saying what to fix."""
+    Whether it is paused isn't among them: Pause/Resume sets that, and a new
+    target starts scraping. Raises FormError saying what to fix."""
     name = (form.get("name") or "").strip()
     url = (form.get("url") or "").strip()
     if not name:
@@ -241,7 +241,7 @@ def parse_form(form, existing: PrometheusTarget | None = None) -> dict:
     return {"name": name, "url": url, "token": token,
             "verify_tls": bool(form.get("verify_tls")), "interval_seconds": interval,
             "keep": patterns(form.get("keep") or ""), "drop": patterns(form.get("drop") or ""),
-            "series_cap": cap, "enabled": bool(form.get("enabled"))}
+            "series_cap": cap}
 
 
 # ── What the newest scrape says ──────────────────────────────────────────────
@@ -253,13 +253,13 @@ STALE_SCRAPES = 3
 
 @dataclass
 class TargetState:
-    reach: str                 # up | down | stale | pending | off
+    reach: str                 # up | down | stale | pending | paused
     says: str                  # one line, in words
 
 
 def target_state(target: PrometheusTarget, now: datetime) -> TargetState:
     if not target.enabled:
-        return TargetState("off", "Not scraped: turned off.")
+        return TargetState("paused", "Paused: not scraped until it's resumed.")
     if target.last_scraped_at is None:
         return TargetState("pending", "Not scraped yet.")
     if (now - target.last_scraped_at).total_seconds() > STALE_SCRAPES * max(target.interval_seconds, 1):

plugins/prometheus/templates/prometheus/form.html

@@ -51,9 +51,6 @@
       </div>
     </div>
     <div style="display:flex;gap:1.5rem;flex-wrap:wrap;margin-bottom:0.9rem;">
-      <label style="display:flex;gap:0.5rem;align-items:center;cursor:pointer;">
-        <input type="checkbox" name="enabled" value="on"{% if v.enabled %} checked{% endif %}> Scrape this target
-      </label>
       <label style="display:flex;gap:0.5rem;align-items:center;cursor:pointer;">
         <input type="checkbox" name="verify_tls" value="on"{% if v.verify_tls %} checked{% endif %}> Check its HTTPS certificate
       </label>

plugins/prometheus/templates/prometheus/index.html

@@ -23,13 +23,16 @@
     {% if t.reach == 'up' %}{{ status_badge('up', 'Answering') }}
     {% elif t.reach == 'down' %}{{ status_badge('down', 'Not answering') }}
     {% elif t.reach == 'stale' %}{{ status_badge('stale', 'Not scraped') }}
-    {% elif t.reach == 'off' %}{{ status_badge('stale', 'Turned off') }}
+    {% elif t.reach == 'paused' %}{{ status_badge('paused') }}
     {% else %}{{ status_badge('pending', 'Not scraped yet') }}{% endif %}
     <h2 id="prom-{{ t.id }}" class="section-title" style="margin:0;"><a href="/plugins/prometheus/targets/{{ t.id }}">{{ t.name }}</a></h2>
     <span class="field-hint mono" style="min-width:0;max-width:28rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;" title="{{ t.url }}">{{ t.url }}</span>
     <span class="page-actions" style="margin-left:auto;">
       <a href="/plugins/prometheus/targets/{{ t.id }}" class="btn btn-sm btn-ghost">Series</a>
-      {% if admin %}<a href="/plugins/prometheus/targets/{{ t.id }}/edit" class="btn btn-sm btn-ghost">Edit</a>{% endif %}
+      {% if admin %}<a href="/plugins/prometheus/targets/{{ t.id }}/edit" class="btn btn-sm btn-ghost">Edit</a>
+      <form method="post" action="/plugins/prometheus/targets/{{ t.id }}/toggle">{{ csrf_field() }}
+        <button type="submit" class="btn btn-sm btn-ghost">{{ "Pause" if t.enabled else "Resume" }}</button>
+      </form>{% endif %}
     </span>
   </div>
 
@@ -38,7 +41,7 @@
   <p class="field-hint" style="margin:0 0 0.6rem;">
     {%- if t.ok_at %}Last answered {{ t.ok_at|ago }}.{% else %}It has never answered.{% endif %}
     Tried {{ t.scraped_at|ago }}.</p>
-  {% elif t.reach in ('stale', 'off') %}
+  {% elif t.reach in ('stale', 'paused') %}
   <p class="field-hint" style="margin:0 0 0.6rem;">{{ t.says }}{% if t.scraped_at %} Last scraped {{ t.scraped_at|ago }}.{% endif %}</p>
   {% elif t.reach == 'pending' %}
   <p class="field-hint" style="margin:0 0 0.6rem;">Not scraped yet: the first scrape runs within seconds of saving.</p>

plugins/prometheus/templates/prometheus/target.html

@@ -12,7 +12,10 @@
 {% block content %}
 {% set admin = session.user_role == 'admin' %}
 {% call page_header(target.name, target.url) %}
-  {% if admin %}<a href="/plugins/prometheus/targets/{{ target.id }}/edit" class="btn btn-sm btn-ghost">Edit</a>{% endif %}
+  {% if admin %}<a href="/plugins/prometheus/targets/{{ target.id }}/edit" class="btn btn-sm btn-ghost">Edit</a>
+  <form method="post" action="/plugins/prometheus/targets/{{ target.id }}/toggle">{{ csrf_field() }}
+    <button type="submit" class="btn btn-sm btn-ghost">{{ "Pause" if target.enabled else "Resume" }}</button>
+  </form>{% endif %}
 {% endcall %}
 
 <p class="page-verdict">
@@ -20,7 +23,7 @@
   {% elif target.reach == 'down' %}{{ status_badge('down', 'Not answering') }} <span class="tone-crit">{{ target.says }}</span>
     {% if target.ok_at %}Last answered {{ target.ok_at|ago }}; the values below are from then.{% else %}It has never answered.{% endif %}
   {% elif target.reach == 'stale' %}{{ status_badge('stale', 'Not scraped') }} {{ target.says }}
-  {% elif target.reach == 'off' %}{{ status_badge('stale', 'Turned off') }} {{ target.says }}
+  {% elif target.reach == 'paused' %}{{ status_badge('paused') }} {{ target.says }}
   {% else %}{{ status_badge('pending', 'Not scraped yet') }} The first scrape runs within seconds of saving.{% endif %}
 </p>
 {% if target.capped %}

plugins/syslog/patterns.py

@@ -108,8 +108,7 @@ def parse_form(form) -> dict:
     if window not in WINDOWS:
         window = 15
     return {"name": name, "phrases": phrases, "max_severity": max_severity,
-            "source_id": form.get("source_id") or None, "window_minutes": window,
-            "enabled": "enabled" in form}
+            "source_id": form.get("source_id") or None, "window_minutes": window}
 
 
 def matches(pattern, severity: int, message: str) -> bool:

plugins/syslog/routes.py

@@ -381,13 +381,13 @@ async def add_preset(key: str):
 @syslog_bp.get("/patterns/new")
 @require_role(UserRole.admin)
 async def new_pattern():
-    return await _render_pattern_form(None, {"window_minutes": 15, "enabled": True})
+    return await _render_pattern_form(None, {"window_minutes": 15})
 
 
 def _typed_pattern(form) -> dict:
     return {"name": form.get("name", ""), "phrases": form.get("phrases", ""),
             "max_severity": form.get("max_severity", ""), "source_id": form.get("source_id", ""),
-            "window_minutes": form.get("window_minutes", 15, type=int), "enabled": "enabled" in form}
+            "window_minutes": form.get("window_minutes", 15, type=int)}
 
 
 @syslog_bp.post("/patterns/new")
@@ -426,7 +426,7 @@ async def edit_pattern(pattern_id: str):
     return await _render_pattern_form(p, {
         "name": p.name, "phrases": "\n".join(p.phrases or []),
         "max_severity": "" if p.max_severity is None else str(p.max_severity),
-        "source_id": p.source_id or "", "window_minutes": p.window_minutes, "enabled": p.enabled})
+        "source_id": p.source_id or "", "window_minutes": p.window_minutes})
 
 
 @syslog_bp.post("/patterns/<pattern_id>/edit")
@@ -451,6 +451,20 @@ async def save_pattern(pattern_id: str):
     return redirect(PATTERNS)
 
 
+@syslog_bp.post("/patterns/<pattern_id>/toggle")
+@require_role(UserRole.admin)
+async def toggle_pattern(pattern_id: str):
+    """Pause a pattern's counting, or resume it, from the patterns list."""
+    async with current_app.db_sessionmaker() as db:
+        async with db.begin():
+            p = await _pattern_or_404(db, pattern_id)
+            p.enabled = not p.enabled
+            enabled, name = p.enabled, p.name
+    await log_audit(current_app, *_actor(), "syslog.pattern_resumed" if enabled else "syslog.pattern_paused",
+                    entity_type="syslog_pattern", entity_id=pattern_id, detail={"name": name})
+    return redirect(PATTERNS)
+
+
 @syslog_bp.post("/patterns/<pattern_id>/delete")
 @require_role(UserRole.admin)
 async def delete_pattern(pattern_id: str):

plugins/syslog/templates/syslog/pattern_form.html

@@ -45,12 +45,6 @@
         </select>
         <span class="field-hint">The count is of matches this far back, so an alert on it clears this long after the last one.</span>
       </div>
-      <div class="field">
-        <label class="field-check">
-          <input type="checkbox" name="enabled"{% if v.enabled %} checked{% endif %}>
-          Counted: off keeps the pattern without counting it
-        </label>
-      </div>
     </div>
   </section>
   <div class="page-actions">

plugins/syslog/templates/syslog/patterns.html

@@ -1,7 +1,7 @@
 {# plugins/syslog/templates/syslog/patterns.html — telling phrases counted in
    each source's lines every minute, so an alert rule can watch them (#6001). #}
 {% extends "base.html" %}
-{% from "_macros.html" import crumbs, page_header, empty_state %}
+{% from "_macros.html" import crumbs, page_header, empty_state, status_badge %}
 {% block title %}Patterns — Syslog — Steward{% endblock %}
 {% block breadcrumb %}{{ crumbs([("Syslog", "/plugins/syslog/"), ("Patterns", "")]) }}{% endblock %}
 {% block content %}
@@ -23,7 +23,7 @@
     <tbody>
     {% for p in patterns %}
     <tr>
-      <td>{{ p.name }}{% if not p.enabled %} <span class="field-hint">(off)</span>{% endif %}<div class="field-hint mono">{{ p.metric }}</div></td>
+      <td>{{ p.name }}{% if not p.enabled %} {{ status_badge('paused') }}{% endif %}<div class="field-hint mono">{{ p.metric }}</div></td>
       <td>
         {% if p.phrases %}<span class="mono" title="{{ p.phrases|join('\n') }}">{{ p.phrases[:3]|join(" · ") }}{% if p.phrases|length > 3 %} · +{{ p.phrases|length - 3 }} more{% endif %}</span>{% endif %}
         {% if p.severity %}<div class="field-hint">{{ p.severity }} and worse</div>{% endif %}
@@ -37,7 +37,10 @@
       {% if can_alert %}
       <td style="white-space:nowrap;">
         {% if p.alert_resource %}<a class="btn btn-sm btn-ghost" href="/alerts/rules/new?source_module=syslog&amp;resource_name={{ p.alert_resource|urlencode }}&amp;metric_name={{ p.metric|urlencode }}">Alert on it</a>{% endif %}
-        {% if admin %}<a class="btn btn-sm btn-ghost" href="/plugins/syslog/patterns/{{ p.id }}/edit">Edit</a>{% endif %}
+        {% if admin %}<a class="btn btn-sm btn-ghost" href="/plugins/syslog/patterns/{{ p.id }}/edit">Edit</a>
+        <form method="post" action="/plugins/syslog/patterns/{{ p.id }}/toggle" style="display:inline;margin:0;">{{ csrf_field() }}
+          <button type="submit" class="btn btn-sm btn-ghost">{{ "Pause" if p.enabled else "Resume" }}</button>
+        </form>{% endif %}
       </td>
       {% endif %}
     </tr>