Custom Branding: Relative URL should be allowed (opensearch-project#5572

)

When enabling the advanced setting `courier:ignoreFilterIfFieldNotInIndex`
Custom OpenSearch Query DSL filters could technically be applied to index
patterns that map to indices that are not exactly the same. Since the
custom query filter is a user input then users can really type anything
that they need. Or any field that they know is present but we do not know
for sure.

Therefore, we can check if the id which is the index pattern title to check
if we should apply the filter or not.

Issue resolved:
https://github.com/opensearch-project/dashboards-visualizations/issues/281

Issue could be closed:
opensearch-project#5423

---------

Signed-off-by: Alankarsharma <alankar.sharma005@gmail.com>
Signed-off-by: Kawika Avilla <kavilla414@gmail.com>
Co-authored-by: opensearch-trigger-bot[bot] <98922864+opensearch-trigger-bot[bot]@users.noreply.github.com>
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Kawika Avilla <kavilla414@gmail.com>
Co-authored-by: Qingyang(Abby) Hu <abigailhu2000@gmail.com>

CHANGELOG.md

@@ -22,6 +22,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - [Workspace] Setup workspace skeleton and implement basic CRUD API ([#5075](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/5075))
 - [Decouple] Add new cross compatibility check core service which export functionality for plugins to verify if their OpenSearch plugin counterpart is installed on the cluster or has incompatible version to configure the plugin behavior([#4710](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/4710))
 - [Discover] Display inner properties in the left navigation bar [#5429](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/5429)
+- [Custom Branding] Relative URL should be allowed for logos ([#5572](https://github.com/opensearch-project/OpenSearch-Dashboards/pull/5572))
 
 ### 🐛 Bug Fixes
 

src/core/server/rendering/rendering_service.test.ts

@@ -195,6 +195,11 @@ describe('RenderingService', () => {
       const result = await service.isUrlValid('/', 'config');
       expect(result).toEqual(false);
     });
+
+    it('checks relative URL returns true', async () => {
+      const result = await service.isUrlValid('/demo/opensearch_mark_default.png', 'config');
+      expect(result).toEqual(true);
+    });
   });
 
   describe('isTitleValid()', () => {

src/core/server/rendering/rendering_service.tsx

@@ -371,6 +371,9 @@ export class RenderingService {
       this.logger.get('branding').error(`${configName} config is invalid. Using default branding.`);
       return false;
     }
+    if (url.startsWith('/')) {
+      return true;
+    }
     return await Axios.get(url, {
       httpsAgent: this.httpsAgent,
       adapter: 'http',