plugin-search-backend-module-elasticsearch: Opensearch provider

This patch continues the work started by jinnjwu on
https://github.com/backstage/backstage/pull/14988

It creates a new provider, opensearch, allowing the usage of it
outside of managed aws solutions.

Signed-off-by: Renan Mendes Carvalho <aitherios@gmail.com>

plugins/search-backend-module-elasticsearch/api-report.md

@@ -421,7 +421,7 @@ export interface OpenSearchElasticSearchClientOptions
   // (undocumented)
   nodes?: string | string[] | OpenSearchNodeOptions | OpenSearchNodeOptions[];
   // (undocumented)
-  provider?: 'aws';
+  provider?: 'aws' | 'opensearch';
 }
 
 // @public (undocumented)

plugins/search-backend-module-elasticsearch/config.d.ts

@@ -138,10 +138,11 @@ export interface Config {
       bearer: string;
     };*/
           }
+
         /**
          *  AWS = In house hosting Open Search
          */
-          | {
+        | {
             provider: 'opensearch';
             /**
              * Node configuration.
@@ -166,7 +167,7 @@ export interface Config {
               | {
                   apiKey: string;
                 };
-          }      
+          }
       );
     };
   };

plugins/search-backend-module-elasticsearch/src/engines/ElasticSearchClientOptions.ts

@@ -25,7 +25,7 @@ import type { ConnectionOptions as TLSConnectionOptions } from 'tls';
 export const isOpenSearchCompatible = (
   opts: ElasticSearchClientOptions,
 ): opts is OpenSearchElasticSearchClientOptions => {
-  return opts?.provider === 'aws';
+  return ['aws', 'opensearch'].includes(opts?.provider ?? '');
 };
 
 /**
@@ -50,7 +50,7 @@ export type ElasticSearchClientOptions =
  */
 export interface OpenSearchElasticSearchClientOptions
   extends BaseElasticSearchClientOptions {
-  provider?: 'aws';
+  provider?: 'aws' | 'opensearch';
   auth?: OpenSearchAuth;
   connection?: OpenSearchConnectionConstructor;
   node?: string | string[] | OpenSearchNodeOptions | OpenSearchNodeOptions[];

plugins/search-backend-module-elasticsearch/src/engines/ElasticSearchClientWrapper.test.ts

@@ -336,5 +336,24 @@ describe('ElasticSearchClientWrapper', () => {
         body: { actions: input.actions },
       });
     });
+
+    it('accepts provider "opensearch"', async () => {
+      osOptions = {
+        provider: 'opensearch',
+        node: 'https://my-opensearch-instance.address.com',
+        // todo(backstage/techdocs-core): Remove the following ts-ignore when
+        // @short.io/opensearch-mock is updated to work w/opensearch >= 2.0.0
+        // @ts-ignore
+        connection: mock.getConnection(),
+      };
+
+      const wrapper = ElasticSearchClientWrapper.fromClientOptions(osOptions);
+      expect(OpenSearchClient).toHaveBeenCalledWith(osOptions);
+
+      const searchInput = { index: 'xyz', body: { eg: 'etc' } };
+      const result = (await wrapper.search(searchInput)) as any;
+      expect(result.client).toBe('os');
+      expect(result.args).toStrictEqual(searchInput);
+    });
   });
 });

plugins/search-backend-module-elasticsearch/src/engines/ElasticSearchSearchEngine.ts

@@ -150,6 +150,8 @@ export class ElasticSearchSearchEngine implements SearchEngine {
       logger.info('Initializing Elastic.co ElasticSearch search engine.');
     } else if (options.provider === 'aws') {
       logger.info('Initializing AWS OpenSearch search engine.');
+    } else if (options.provider === 'opensearch') {
+      logger.info('Initializing OpenSearch search engine.');
     } else {
       logger.info('Initializing ElasticSearch search engine.');
     }
@@ -452,6 +454,24 @@ export async function createElasticSearchClientOptions(
         : {}),
     };
   }
+  if (config.getOptionalString('provider') === 'opensearch') {
+    const authConfig = config.getConfig('auth');
+    return {
+      provider: 'opensearch',
+      auth: {
+        username: authConfig.getString('username'),
+        password: authConfig.getString('password'),
+      },
+      ...(sslConfig
+        ? {
+            ssl: {
+              rejectUnauthorized:
+                sslConfig?.getOptionalBoolean('rejectUnauthorized'),
+            },
+          }
+        : {}),
+    };
+  }
   const authConfig = config.getOptionalConfig('auth');
   const auth =
     authConfig &&