filter healthcheck events and static assets for sentry transactions

app/routes/resources+/healthcheck.tsx

@@ -4,18 +4,19 @@ import { prisma } from '#app/utils/db.server.ts'
 
 export async function loader({ request }: DataFunctionArgs) {
 	const host =
-    request.headers.get('X-Forwarded-Host') ?? request.headers.get('host')
+		request.headers.get('X-Forwarded-Host') ?? request.headers.get('host')
 
 	try {
 		// if we can connect to the database and make a simple query
 		// and make a HEAD request to ourselves, then we're good.
 		await Promise.all([
 			prisma.user.count(),
-			fetch(`${new URL(request.url).protocol}${host}`, {method: 'HEAD'}).then(
-        r => {
-          if (!r.ok) return Promise.reject(r)
-        },
-      ),
+			fetch(`${new URL(request.url).protocol}${host}`, {
+				method: 'HEAD',
+				headers: { 'X-Healthcheck': 'true' },
+			}).then(r => {
+				if (!r.ok) return Promise.reject(r)
+			}),
 		])
 		return new Response('OK')
 	} catch (error: unknown) {

app/utils/monitoring.server.ts

@@ -5,10 +5,26 @@ export function init() {
 	Sentry.init({
 		dsn: ENV.SENTRY_DSN,
 		environment: ENV.MODE,
-		tracesSampleRate: 1,
+		tracesSampleRate: ENV.MODE === 'production' ? 1 : 0,
+		denyUrls: [
+			/\/resources\/healthcheck/,
+			// TODO: be smarter about the public assets...
+			/\/build\//,
+			/\/favicons\//,
+			/\/img\//,
+			/\/fonts\//,
+			/\/favicon.ico/,
+			/\/site\.webmanifest/,
+		],
 		integrations: [
 			new Sentry.Integrations.Http({ tracing: true }),
 			new Sentry.Integrations.Prisma({ client: prisma }),
 		],
+		beforeSendTransaction(event) {
+			// ignore all healthcheck related transactions
+			if (event.request?.headers?.['X-Healthcheck'] === 'true') return null
+
+			return event
+		},
 	})
 }