feat(monitoring): add stats counters API and public status page

Add GET /api/stats exposing cumulative counters (feeds created/deleted,
emails received/rejected, recent date-times) plus live values (active
feeds, active WebSub subscriptions). Counters persist in a stats:counters
KV singleton and are incremented at the email-processing chokepoint and
feed create/delete paths. Replace the / → /admin redirect with a public
status page rendering these figures with a link to the admin.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
This commit is contained in:
Julien Herr
2026-05-23 09:50:51 +02:00
parent f4d5edda0e
commit b534ce5bf8
15 changed files with 484 additions and 6 deletions
+5
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@@ -32,7 +32,9 @@ Single Cloudflare Worker built with Hono. Routes:
| Method | Path | Purpose |
| ------------------------------------ | ---------------------------------------------------------------------- | ------- |
| `GET /` | Public status page (monitoring counters + link to admin) |
| `POST /api/inbound` | Webhook from ForwardEmail; IP-allowlisted to their MX sources |
| `GET /api/stats` | Public monitoring counters (JSON) |
| `GET /rss/:feedId` | Public RSS 2.0 feed |
| `GET /atom/:feedId` | Public Atom feed (with WebSub hub header) |
| `GET /entries/:feedId/:entryId` | Individual email HTML view |
@@ -56,6 +58,8 @@ src/
entries.ts # Single email HTML view
files.ts # R2 attachment serving
hub.ts # WebSub hub
home.tsx # Public status page (GET /)
stats.ts # Monitoring counters API (GET /api/stats)
admin.tsx # Admin UI entrypoint (hono/jsx)
admin/ # Admin sub-modules
feeds.tsx # Feeds CRUD UI
@@ -99,6 +103,7 @@ All data lives in the `EMAIL_STORAGE` KV namespace:
| `feed:<feedId>:metadata` | `{ emails: Array<{ key, subject, receivedAt, size?, attachmentIds? }> }` |
| `feed:<feedId>:<timestamp>` | Full `EmailData` |
| `websub:<feedId>:<callbackHash>` | `WebSubSubscription` |
| `stats:counters` | `Counters` (cumulative monitoring counters singleton) |
`src/lib/storage.ts` contains key-builder helpers — use them; don't inline key strings in routes.
+22
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@@ -41,6 +41,7 @@ Common path:
2. The Worker resolves the feed from the recipient address and stores the email in KV.
3. `https://yourdomain.com/rss/:feedId` renders RSS from stored items.
4. `/admin` provides feed management and email deletion.
5. `https://yourdomain.com/` shows a public status page with monitoring counters and a link to the admin.
Main routes:
@@ -50,6 +51,27 @@ Main routes:
- `src/routes/atom.ts`: Atom feed rendering
- `src/routes/files.ts`: attachment file serving from R2
- `src/routes/admin.ts`: admin UI + feed CRUD
- `src/routes/home.tsx`: public status page (`GET /`)
- `src/routes/stats.ts`: monitoring counters API (`GET /api/stats`)
### Monitoring
`GET /api/stats` returns JSON counters (public, no auth) for uptime/monitoring tools:
| Field | Meaning |
| ----------------------------- | -------------------------------------------------------- |
| `active_feeds` | Feeds currently configured (live) |
| `feeds_created` | Total feeds ever created (cumulative) |
| `feeds_deleted` | Total feeds ever deleted (cumulative) |
| `emails_received` | Total emails ingested successfully (cumulative) |
| `emails_rejected` | Total emails rejected during validation (cumulative) |
| `websub_subscriptions_active` | Active WebSub subscriptions (live) |
| `last_email_at` | ISO 8601 date-time of the last ingested email |
| `last_feed_created_at` | ISO 8601 date-time of the last feed creation |
| `first_seen` | ISO 8601 date-time the instance first recorded a counter |
The same figures are rendered on the public status page at `GET /`. Cumulative counters
are persisted in the `EMAIL_STORAGE` KV under the `stats:counters` key.
## Requirements
+3
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@@ -21,3 +21,6 @@ export const MAX_LEASE_SECONDS = 30 * 24 * 3600; // 30 days
/** KV key for the global feed list. */
export const FEEDS_LIST_KEY = "feeds:list";
/** KV key for the monitoring counters singleton. */
export const STATS_KEY = "stats:counters";
+11 -2
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@@ -6,6 +6,8 @@ import { handle as handleAtom } from "./routes/atom";
import { handle as handleAdmin } from "./routes/admin";
import { handle as handleEntry } from "./routes/entries";
import { handle as handleFiles } from "./routes/files";
import { handle as handleStats } from "./routes/stats";
import { handle as handleHome } from "./routes/home";
import { hubRouter } from "./routes/hub";
import { handleCloudflareEmail } from "./lib/cloudflare-email";
import { Env } from "./types";
@@ -15,6 +17,7 @@ import {
purgeExpiredFeeds,
removeFeedsFromListBulk,
} from "./routes/admin/helpers";
import { bumpCounters } from "./utils/stats";
import { FORWARD_EMAIL_IPS_CACHE_TTL_MS } from "./config/constants";
type AppEnv = { Bindings: Env };
@@ -137,6 +140,9 @@ api.use("/inbound", async (c, next) => {
// API routes (inbound webhook)
api.post("/inbound", handleInbound);
// Public monitoring stats (JSON)
api.get("/stats", handleStats);
// RSS feed routes (public)
rss.get("/:feedId", handleRSS);
@@ -164,8 +170,8 @@ app.route("/hub", hubRouter);
// Health check endpoint for monitoring
app.get("/health", (c) => c.json({ status: "ok", timestamp: Date.now() }));
// Root path redirects to admin dashboard
app.get("/", (c) => c.redirect("/admin"));
// Public status page (counters + link to admin)
app.get("/", handleHome);
// Catch-all for 404s
app.all("*", (c) => c.text("Not Found", 404));
@@ -192,6 +198,9 @@ export default {
}
if (expiredIds.length > 0) {
await removeFeedsFromListBulk(env.EMAIL_STORAGE, expiredIds);
await bumpCounters(env.EMAIL_STORAGE, {
feeds_deleted: expiredIds.length,
});
logger.info("Feed TTL cleanup", { deleted: expiredIds.length });
}
},
+29
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@@ -6,6 +6,7 @@ import {
ProcessEmailInput,
RawAttachment,
} from "./email-processor";
import { getCounters } from "../utils/stats";
const VALID_FEED_ID = "apple.mountain.42";
const VALID_TO = `${VALID_FEED_ID}@test.getmynews.app`;
@@ -467,3 +468,31 @@ describe("processEmail — attachments", () => {
expect(mockR2._has(oldAttachmentId)).toBe(false);
});
});
describe("processEmail — monitoring counters", () => {
it("increments emails_received and sets last_email_at on success", async () => {
const env = createMockEnv();
await env.EMAIL_STORAGE.put(
`feed:${VALID_FEED_ID}:config`,
JSON.stringify({}),
);
await processEmail(makeInput(), env as any);
const counters = await getCounters(env.EMAIL_STORAGE as any);
expect(counters.emails_received).toBe(1);
expect(counters.emails_rejected).toBe(0);
expect(counters.last_email_at).toBeDefined();
});
it("increments emails_rejected when validation fails", async () => {
const env = createMockEnv();
// No feed config → 404 rejection
await processEmail(makeInput(), env as any);
const counters = await getCounters(env.EMAIL_STORAGE as any);
expect(counters.emails_rejected).toBe(1);
expect(counters.emails_received).toBe(0);
});
});
+9 -1
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@@ -7,6 +7,7 @@ import {
FeedMetadata,
} from "../types";
import { notifySubscribers } from "../utils/websub";
import { bumpCounters } from "../utils/stats";
import { logger } from "./logger";
import { FEED_MAX_BYTES } from "../config/constants";
@@ -248,8 +249,15 @@ export async function processEmail(
ctx?: ExecutionContext,
): Promise<Response> {
const validation = await validateEmail(input, env);
if (!validation.ok) return validation.response;
if (!validation.ok) {
await bumpCounters(env.EMAIL_STORAGE, { emails_rejected: 1 });
return validation.response;
}
await storeEmail(validation.feedId, input, env, ctx);
await bumpCounters(env.EMAIL_STORAGE, {
emails_received: 1,
last_email_at: new Date().toISOString(),
});
return new Response("Email processed successfully", { status: 200 });
}
+16 -1
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@@ -2,6 +2,7 @@ import { Hono } from "hono";
import { z } from "zod";
import { Env, FeedConfig, FeedMetadata } from "../../types";
import { generateFeedId } from "../../utils/id-generator";
import { bumpCounters } from "../../utils/stats";
import { waitUntilSafe } from "../../utils/worker";
import { feedRssUrl, feedEmailAddress } from "../../utils/urls";
import { logger } from "../../lib/logger";
@@ -191,6 +192,11 @@ feedsRouter.post("/create", async (c) => {
expiresAt,
);
await bumpCounters(emailStorage, {
feeds_created: 1,
last_feed_created_at: new Date().toISOString(),
});
if (isJson) {
return c.json({
feedId,
@@ -528,7 +534,10 @@ feedsRouter.post("/:feedId/delete", async (c) => {
try {
await deleteFeedFast(emailStorage, feedId);
await removeFeedFromList(emailStorage, feedId);
const removed = await removeFeedFromList(emailStorage, feedId);
if (removed) {
await bumpCounters(emailStorage, { feeds_deleted: 1 });
}
waitUntilSafe(
c,
@@ -658,6 +667,9 @@ feedsRouter.post("/bulk-delete", async (c) => {
}
const deletedFeedIds = await removeFeedsFromListBulk(emailStorage, okIds);
if (deletedFeedIds.length > 0) {
await bumpCounters(emailStorage, { feeds_deleted: deletedFeedIds.length });
}
const removed = new Set(deletedFeedIds);
okIds.forEach((feedId) => {
@@ -707,6 +719,9 @@ feedsRouter.post("/bulk-delete", async (c) => {
}
const deletedFeedIds = await removeFeedsFromListBulk(emailStorage, okIds);
if (deletedFeedIds.length > 0) {
await bumpCounters(emailStorage, { feeds_deleted: deletedFeedIds.length });
}
return c.redirect(
`${redirectBase}&message=bulkDeleted&count=${deletedFeedIds.length}`,
+3 -2
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@@ -8,10 +8,11 @@ const designSystem = [variablesCss, layoutCss, componentsCss, utilitiesCss].join
type LayoutProps = {
title: string;
label?: string;
children: import("hono/jsx").Child;
};
export const Layout = ({ title, children }: LayoutProps) => {
export const Layout = ({ title, label = "admin", children }: LayoutProps) => {
return (
<html>
<head>
@@ -38,7 +39,7 @@ export const Layout = ({ title, children }: LayoutProps) => {
<a href="https://kill-the.news/" class="site-header-logo" target="_blank" rel="noopener">
kill-the-news
</a>
<span class="site-header-label">admin</span>
<span class="site-header-label">{label}</span>
</header>
{children}
<footer class="site-footer">
+57
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@@ -0,0 +1,57 @@
import { Context } from "hono";
import { Env } from "../types";
import { getStats } from "../utils/stats";
import { Layout } from "./admin/ui";
function formatDateTime(iso?: string): string {
if (!iso) return "Never";
const date = new Date(iso);
if (Number.isNaN(date.getTime())) return "Never";
return date.toISOString().replace("T", " ").replace(/\.\d+Z$/, " UTC");
}
export async function handle(c: Context<{ Bindings: Env }>): Promise<Response> {
const stats = await getStats(c.env);
const cards: Array<{ label: string; value: string | number; time?: boolean }> =
[
{ label: "Active feeds", value: stats.active_feeds },
{ label: "Feeds created", value: stats.feeds_created },
{ label: "Feeds deleted", value: stats.feeds_deleted },
{ label: "Emails received", value: stats.emails_received },
{ label: "Emails rejected", value: stats.emails_rejected },
{ label: "WebSub subscribers", value: stats.websub_subscriptions_active },
{ label: "Last email", value: formatDateTime(stats.last_email_at), time: true },
{ label: "Last feed created", value: formatDateTime(stats.last_feed_created_at), time: true },
{ label: "Online since", value: formatDateTime(stats.first_seen), time: true },
];
return c.html(
<Layout title="Status" label="status">
<div class="container fade-in">
<div class="header-with-actions">
<div class="header-title">
<h1>kill-the-news</h1>
<p>Instance status &amp; monitoring</p>
</div>
<div class="header-actions">
<a href="/admin" class="button">
Go to admin
</a>
</div>
</div>
<div class="stats-grid">
{cards.map((card) => (
<div class="card stat-card">
<span class={`stat-value${card.time ? " stat-value-time" : ""}`}>
{card.value}
</span>
<span class="stat-label">{card.label}</span>
</div>
))}
</div>
</div>
</Layout>,
);
}
+66
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@@ -0,0 +1,66 @@
import { describe, it, expect } from "vitest";
import worker from "../index";
import { createMockEnv } from "../test/setup";
import { bumpCounters } from "../utils/stats";
import { FEEDS_LIST_KEY } from "../config/constants";
import type { Env, StatsResponse } from "../types";
function req(path: string, init: RequestInit = {}): Request {
return new Request(`https://test.getmynews.app${path}`, init);
}
describe("GET /api/stats", () => {
it("returns zeroed stats for a fresh instance", async () => {
const env = createMockEnv() as unknown as Env;
const res = await worker.fetch(req("/api/stats"), env);
expect(res.status).toBe(200);
const body = (await res.json()) as StatsResponse;
expect(body).toMatchObject({
feeds_created: 0,
feeds_deleted: 0,
emails_received: 0,
emails_rejected: 0,
active_feeds: 0,
websub_subscriptions_active: 0,
});
});
it("reflects persisted counters and live values", async () => {
const env = createMockEnv() as unknown as Env;
await env.EMAIL_STORAGE.put(
FEEDS_LIST_KEY,
JSON.stringify({ feeds: [{ id: "a", title: "A" }] }),
);
await env.EMAIL_STORAGE.put("websub:a:hash", "{}");
await bumpCounters(env.EMAIL_STORAGE, {
emails_received: 3,
emails_rejected: 1,
feeds_created: 1,
});
const res = await worker.fetch(req("/api/stats"), env);
const body = (await res.json()) as StatsResponse;
expect(body.active_feeds).toBe(1);
expect(body.websub_subscriptions_active).toBe(1);
expect(body.emails_received).toBe(3);
expect(body.emails_rejected).toBe(1);
expect(body.feeds_created).toBe(1);
});
});
describe("GET / (public status page)", () => {
it("returns an HTML status page with counters and an admin link", async () => {
const env = createMockEnv() as unknown as Env;
await bumpCounters(env.EMAIL_STORAGE, { emails_received: 7 });
const res = await worker.fetch(req("/"), env);
expect(res.status).toBe(200);
expect(res.headers.get("Content-Type")).toContain("text/html");
const html = await res.text();
expect(html).toContain('href="/admin"');
expect(html).toContain("Active feeds");
expect(html).toContain("Emails received");
expect(html).toContain("7");
});
});
+7
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@@ -0,0 +1,7 @@
import { Context } from "hono";
import { Env } from "../types";
import { getStats } from "../utils/stats";
export async function handle(c: Context<{ Bindings: Env }>): Promise<Response> {
return c.json(await getStats(c.env));
}
+33
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@@ -1010,3 +1010,36 @@ table.table code {
opacity: 0.6;
pointer-events: none;
}
/* Status page — stat cards grid */
.stats-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
gap: var(--spacing-md);
margin-bottom: var(--spacing-lg);
}
.stat-card {
display: flex;
flex-direction: column;
gap: var(--spacing-xs);
margin-bottom: 0;
}
.stat-value {
font-size: 2rem;
font-weight: 700;
color: var(--color-primary);
line-height: 1.1;
}
.stat-value-time {
font-size: 1rem;
font-weight: 600;
color: var(--color-text-primary);
}
.stat-label {
font-size: 0.85rem;
color: var(--color-text-secondary);
}
+17
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@@ -69,6 +69,23 @@ export interface FeedListItem {
expires_at?: number; // Cached from FeedConfig to avoid per-feed KV reads
}
// Cumulative monitoring counters (persisted as a KV singleton)
export interface Counters {
feeds_created: number;
feeds_deleted: number;
emails_received: number;
emails_rejected: number;
last_email_at?: string; // ISO 8601
last_feed_created_at?: string; // ISO 8601
first_seen?: string; // ISO 8601 — first time counters were written (instance start)
}
// Monitoring API response: persisted counters + live-computed values
export interface StatsResponse extends Counters {
active_feeds: number;
websub_subscriptions_active: number;
}
// WebSub (PubSubHubbub) subscription configuration
export interface WebSubSubscription {
callbackUrl: string;
+122
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@@ -0,0 +1,122 @@
import { describe, it, expect } from "vitest";
import { createMockEnv } from "../test/setup";
import {
getCounters,
bumpCounters,
countKeysByPrefix,
getStats,
} from "./stats";
import { STATS_KEY, FEEDS_LIST_KEY } from "../config/constants";
import { Env } from "../types";
describe("stats helper", () => {
it("returns zeroed counters when nothing is stored", async () => {
const env = createMockEnv() as unknown as Env;
const counters = await getCounters(env.EMAIL_STORAGE);
expect(counters).toMatchObject({
feeds_created: 0,
feeds_deleted: 0,
emails_received: 0,
emails_rejected: 0,
});
expect(counters.first_seen).toBeUndefined();
});
it("accumulates numeric deltas across bumps", async () => {
const env = createMockEnv() as unknown as Env;
const kv = env.EMAIL_STORAGE;
await bumpCounters(kv, { emails_received: 1 });
await bumpCounters(kv, { emails_received: 2, emails_rejected: 1 });
await bumpCounters(kv, { feeds_created: 1, feeds_deleted: 3 });
const counters = await getCounters(kv);
expect(counters.emails_received).toBe(3);
expect(counters.emails_rejected).toBe(1);
expect(counters.feeds_created).toBe(1);
expect(counters.feeds_deleted).toBe(3);
});
it("overwrites date-time fields and sets first_seen once", async () => {
const env = createMockEnv() as unknown as Env;
const kv = env.EMAIL_STORAGE;
await bumpCounters(kv, {
emails_received: 1,
last_email_at: "2026-01-01T00:00:00.000Z",
});
const first = await getCounters(kv);
const firstSeen = first.first_seen;
expect(firstSeen).toBeDefined();
expect(first.last_email_at).toBe("2026-01-01T00:00:00.000Z");
await bumpCounters(kv, {
emails_received: 1,
last_email_at: "2026-02-02T00:00:00.000Z",
});
const second = await getCounters(kv);
expect(second.last_email_at).toBe("2026-02-02T00:00:00.000Z");
expect(second.first_seen).toBe(firstSeen);
});
it("counts keys by prefix", async () => {
const env = createMockEnv() as unknown as Env;
const kv = env.EMAIL_STORAGE;
await kv.put("websub:a:1", "{}");
await kv.put("websub:a:2", "{}");
await kv.put("feed:x:config", "{}");
expect(await countKeysByPrefix(kv, "websub:")).toBe(2);
expect(await countKeysByPrefix(kv, "missing:")).toBe(0);
});
it("getStats combines persisted counters with live values", async () => {
const env = createMockEnv() as unknown as Env;
const kv = env.EMAIL_STORAGE;
await kv.put(
FEEDS_LIST_KEY,
JSON.stringify({
feeds: [
{ id: "a", title: "A" },
{ id: "b", title: "B" },
],
}),
);
await kv.put("websub:a:1", "{}");
await bumpCounters(kv, { emails_received: 5, feeds_created: 2 });
const stats = await getStats(env);
expect(stats.active_feeds).toBe(2);
expect(stats.websub_subscriptions_active).toBe(1);
expect(stats.emails_received).toBe(5);
expect(stats.feeds_created).toBe(2);
});
it("never throws on a failing KV (counters are best-effort)", async () => {
const brokenKv = {
get: async () => {
throw new Error("kv down");
},
put: async () => {
throw new Error("kv down");
},
} as unknown as KVNamespace;
await expect(
bumpCounters(brokenKv, { emails_received: 1 }),
).resolves.toBeUndefined();
expect(await getCounters(brokenKv)).toMatchObject({ emails_received: 0 });
expect(await countKeysByPrefix(brokenKv, "websub:")).toBe(0);
});
it("persists under the stats KV key", async () => {
const env = createMockEnv() as unknown as Env;
const kv = env.EMAIL_STORAGE;
await bumpCounters(kv, { feeds_created: 1 });
const raw = (await kv.get(STATS_KEY, { type: "json" })) as {
feeds_created: number;
};
expect(raw.feeds_created).toBe(1);
});
});
+84
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@@ -0,0 +1,84 @@
import { Counters, Env, StatsResponse } from "../types";
import { STATS_KEY } from "../config/constants";
import { logger } from "../lib/logger";
import { listAllFeeds } from "../routes/admin/helpers";
const EMPTY_COUNTERS: Counters = {
feeds_created: 0,
feeds_deleted: 0,
emails_received: 0,
emails_rejected: 0,
};
export async function getCounters(kv: KVNamespace): Promise<Counters> {
try {
const stored = (await kv.get(STATS_KEY, {
type: "json",
})) as Counters | null;
return { ...EMPTY_COUNTERS, ...(stored || {}) };
} catch (error) {
logger.error("Error reading counters", { error: String(error) });
return { ...EMPTY_COUNTERS };
}
}
/**
* Read-modify-write the counters singleton. KV has no atomic increment, so
* concurrent invocations can lose updates — accepted given KV's eventual
* consistency and this app's low volume (see email-processor.ts storeEmail).
* Never throws: counter failures must not break ingestion or admin flows.
*/
export async function bumpCounters(
kv: KVNamespace,
changes: Partial<Omit<Counters, "first_seen">>,
): Promise<void> {
try {
const current = await getCounters(kv);
current.feeds_created += changes.feeds_created ?? 0;
current.feeds_deleted += changes.feeds_deleted ?? 0;
current.emails_received += changes.emails_received ?? 0;
current.emails_rejected += changes.emails_rejected ?? 0;
if (changes.last_email_at) current.last_email_at = changes.last_email_at;
if (changes.last_feed_created_at)
current.last_feed_created_at = changes.last_feed_created_at;
if (!current.first_seen) current.first_seen = new Date().toISOString();
await kv.put(STATS_KEY, JSON.stringify(current));
} catch (error) {
logger.error("Error updating counters", { error: String(error) });
}
}
export async function countKeysByPrefix(
kv: KVNamespace,
prefix: string,
): Promise<number> {
let total = 0;
let cursor: string | undefined;
try {
do {
const listed = await kv.list({ prefix, cursor, limit: 1000 });
total += listed.keys.length;
cursor = listed.list_complete ? undefined : listed.cursor;
} while (cursor);
} catch (error) {
logger.error("Error counting keys", { prefix, error: String(error) });
}
return total;
}
export async function getStats(env: Env): Promise<StatsResponse> {
const kv = env.EMAIL_STORAGE;
const [counters, feeds, websubCount] = await Promise.all([
getCounters(kv),
listAllFeeds(kv),
countKeysByPrefix(kv, "websub:"),
]);
return {
...counters,
active_feeds: feeds.length,
websub_subscriptions_active: websubCount,
};
}