From 7b38786ee65333d3c184470a8a736bbd3a1b0a8e Mon Sep 17 00:00:00 2001
From: Enzo Mercanti <enzo.mercanti@vtex.com.br>
Date: Thu, 11 Jul 2024 16:03:11 -0300
Subject: [PATCH] fix: add with session metric

---
 CHANGELOG.md                   |  3 +++
 node/directives/withSession.ts | 31 ++++++++++++++++++++++-
 node/metrics/session.ts        | 46 ++++++++++++++++++++++++++++++++++
 3 files changed, 79 insertions(+), 1 deletion(-)
 create mode 100644 node/metrics/session.ts

diff --git a/CHANGELOG.md b/CHANGELOG.md
index af8091f..0c74794 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Added
+- Session audit metrics
+
 ## [1.41.0] - 2024-07-01
 
 ### Added
diff --git a/node/directives/withSession.ts b/node/directives/withSession.ts
index dda5c27..327ac70 100644
--- a/node/directives/withSession.ts
+++ b/node/directives/withSession.ts
@@ -4,13 +4,15 @@ import type { GraphQLField } from 'graphql'
 import { defaultFieldResolver } from 'graphql'
 import { SchemaDirectiveVisitor } from 'graphql-tools'
 
+import sendSessionMetric, { SessionMetric } from '../metrics/session'
+
 export class WithSession extends SchemaDirectiveVisitor {
   public visitFieldDefinition(field: GraphQLField<any, any>) {
     const { resolve = defaultFieldResolver } = field
 
     field.resolve = async (root: any, args: any, context: any, info: any) => {
       const {
-        clients: { session },
+        clients: { session, logger },
       } = context
 
       const token =
@@ -23,6 +25,33 @@ export class WithSession extends SchemaDirectiveVisitor {
         })
         .catch(() => null)
 
+      // we emit a metric for cases where the sessionData is null
+      // so we can identify use cases that are supposed to have sessionData
+      // but do not have it. We currently have a high volume of logs generated
+      // by such cases, so we need to identify and fix them.
+      const operation = field.astNode?.name?.value ?? context.request.url
+      const userAgent = context?.request?.headers['user-agent'] as string
+      const caller = context?.request?.headers['x-vtex-caller'] as string
+      const forwardedHost = context?.request?.headers[
+        'x-forwarded-host'
+      ] as string
+
+      const hasSessionToken = !!context.vtex.sessionToken
+      const hasSessionTokenOnHeader = !!context.request.header?.sessiontoken
+      const hasSessionData = !!context.vtex.sessionData
+
+      const auditMetric = new SessionMetric(context?.vtex?.account, {
+        operation,
+        forwardedHost,
+        caller,
+        userAgent,
+        hasSessionToken,
+        hasSessionTokenOnHeader,
+        hasSessionData,
+      })
+
+      sendSessionMetric(logger, auditMetric)
+
       return resolve(root, args, context, info)
     }
   }
diff --git a/node/metrics/session.ts b/node/metrics/session.ts
new file mode 100644
index 0000000..4e2ebe2
--- /dev/null
+++ b/node/metrics/session.ts
@@ -0,0 +1,46 @@
+import type { Logger } from '@vtex/api/lib/service/logger/logger'
+
+import type { Metric } from '../clients/metrics'
+import { B2B_METRIC_NAME, sendMetric } from '../clients/metrics'
+
+export interface SessionAuditMetric {
+  operation: string
+  forwardedHost: string
+  caller: string
+  userAgent: string
+  hasSessionToken: boolean
+  hasSessionTokenOnHeader: boolean
+  hasSessionData: boolean
+}
+
+export class SessionMetric implements Metric {
+  public readonly description: string
+  public readonly kind: string
+  public readonly account: string
+  public readonly fields: SessionAuditMetric
+  public readonly name = B2B_METRIC_NAME
+  public error?: string
+
+  constructor(account: string, fields: SessionAuditMetric) {
+    this.account = account
+    this.fields = fields
+    this.kind = 'b2b-storefront-permissions-session-event'
+    this.description = 'Session metric event'
+  }
+}
+
+const sendSessionMetric = async (
+  logger: Logger,
+  sessionMetric: SessionMetric
+) => {
+  try {
+    await sendMetric(sessionMetric)
+  } catch (error) {
+    logger.error({
+      error,
+      message: `Error to send metrics from session metric`,
+    })
+  }
+}
+
+export default sendSessionMetric