[server] Metrics for sessions with JWTs WEB-102 (#17302)

* [server] Metrics for sessions with JWTs

* retest

* Fix

* Fix

* Fix

* fix

Author: easyCZ

components/server/src/auth/jwt.spec.ts

@@ -76,7 +76,7 @@ class TestAuthJWT {
         const encoded = await sign({}, keypair.privateKey, {
             algorithm: "RS512",
             expiresIn: "1d",
-            issuer: this.config.hostUrl.toStringWoRootSlash(),
+            issuer: "https://mp-server-d7650ec945.preview.gitpod-dev.com",
             keyid: keypair.id,
             subject,
         });

components/server/src/prometheus-metrics.ts

@@ -26,6 +26,7 @@ export function registerServerMetrics(registry: prometheusClient.Registry) {
     registry.registerMetric(spicedbClientLatency);
     registry.registerMetric(dashboardErrorBoundary);
     registry.registerMetric(jwtCookieIssued);
+    registry.registerMetric(sessionsWithJWTs);
 }
 
 const loginCounter = new prometheusClient.Counter({
@@ -67,6 +68,16 @@ export function reportJWTCookieIssued() {
     jwtCookieIssued.inc();
 }
 
+const sessionsWithJWTs = new prometheusClient.Counter({
+    name: "gitpod_server_sessions_with_jwts_total",
+    help: "Total number of sessions which did/or did not contain JWTs",
+    labelNames: ["present"],
+});
+
+export function reportSessionHasJWT(jwtPresent: boolean) {
+    sessionsWithJWTs.inc({ present: `${jwtPresent}` });
+}
+
 const apiConnectionClosedCounter = new prometheusClient.Counter({
     name: "gitpod_server_api_connections_closed_total",
     help: "Total amount of closed API connections",

components/server/src/session-handler.ts

@@ -16,6 +16,7 @@ import { log } from "@gitpod/gitpod-protocol/lib/util/logging";
 import { Config as DBConfig } from "@gitpod/gitpod-db/lib/config";
 import { Config } from "./config";
 import { GitpodHostUrl } from "@gitpod/gitpod-protocol/lib/util/gitpod-host-url";
+import { reportSessionHasJWT } from "./prometheus-metrics";
 
 @injectable()
 export class SessionHandlerProvider {
@@ -40,7 +41,14 @@ export class SessionHandlerProvider {
 
         options.store = this.createStore();
 
-        this.sessionHandler = session(options);
+        this.sessionHandler = (req: express.Request, res: express.Response, next: express.NextFunction) => {
+            const jwt = req.cookies[SessionHandlerProvider.getJWTCookieName(this.config.hostUrl)];
+            const containedJWT = !!jwt;
+
+            reportSessionHasJWT(containedJWT);
+
+            return session(options)(req, res, next);
+        };
     }
 
     protected getCookieOptions(config: Config): express.CookieOptions {