From a501b8c61abfb1571148dc3a0af07ad6dd0883af Mon Sep 17 00:00:00 2001
From: Joe Portner <5295965+jportner@users.noreply.github.com>
Date: Mon, 19 Apr 2021 10:33:51 -0400
Subject: [PATCH] Coalesce nullable string values in usage data to "NULL"
 strings

---
 .../server/core_usage_data/core_usage_data_service.test.ts | 2 +-
 src/core/server/core_usage_data/core_usage_data_service.ts | 7 ++++---
 src/core/server/core_usage_data/types.ts                   | 6 +++---
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/core/server/core_usage_data/core_usage_data_service.test.ts b/src/core/server/core_usage_data/core_usage_data_service.test.ts
index 4b6194521ca6..d1f047c129ef 100644
--- a/src/core/server/core_usage_data/core_usage_data_service.test.ts
+++ b/src/core/server/core_usage_data/core_usage_data_service.test.ts
@@ -191,7 +191,7 @@ describe('CoreUsageDataService', () => {
                   "disableEmbedding": false,
                   "permissionsPolicyConfigured": false,
                   "referrerPolicy": "no-referrer-when-downgrade",
-                  "strictTransportSecurity": null,
+                  "strictTransportSecurity": "NULL",
                   "xContentTypeOptions": "nosniff",
                 },
                 "socketTimeout": 120000,
diff --git a/src/core/server/core_usage_data/core_usage_data_service.ts b/src/core/server/core_usage_data/core_usage_data_service.ts
index 03fb9be61582..78ac977c31a7 100644
--- a/src/core/server/core_usage_data/core_usage_data_service.ts
+++ b/src/core/server/core_usage_data/core_usage_data_service.ts
@@ -226,9 +226,10 @@ export class CoreUsageDataService implements CoreService<CoreUsageDataSetup, Cor
             truststoreConfigured: isConfigured.record(http.ssl.truststore),
           },
           securityResponseHeaders: {
-            strictTransportSecurity: http.securityResponseHeaders.strictTransportSecurity,
-            xContentTypeOptions: http.securityResponseHeaders.xContentTypeOptions,
-            referrerPolicy: http.securityResponseHeaders.referrerPolicy,
+            // ES does not index `null` and it cannot be searched, so we coalesce these to string values instead
+            strictTransportSecurity: http.securityResponseHeaders.strictTransportSecurity ?? 'NULL',
+            xContentTypeOptions: http.securityResponseHeaders.xContentTypeOptions ?? 'NULL',
+            referrerPolicy: http.securityResponseHeaders.referrerPolicy ?? 'NULL',
             permissionsPolicyConfigured: isConfigured.string(
               http.securityResponseHeaders.permissionsPolicy ?? undefined
             ),
diff --git a/src/core/server/core_usage_data/types.ts b/src/core/server/core_usage_data/types.ts
index 8b6f8b92aefc..b29cf41da682 100644
--- a/src/core/server/core_usage_data/types.ts
+++ b/src/core/server/core_usage_data/types.ts
@@ -213,9 +213,9 @@ export interface CoreConfigUsageData {
       clientAuthentication: 'none' | 'optional' | 'required';
     };
     securityResponseHeaders: {
-      strictTransportSecurity: string | null;
-      xContentTypeOptions: string | null;
-      referrerPolicy: string | null;
+      strictTransportSecurity: string;
+      xContentTypeOptions: string;
+      referrerPolicy: string;
       permissionsPolicyConfigured: boolean;
       disableEmbedding: boolean;
     };