implement possibilities to set custom template on elastic search engine

Signed-off-by: Emma Indal <emma.indahl@gmail.com>

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

@@ -32,6 +32,9 @@ class ElasticSearchSearchEngineForTranslatorTests extends ElasticSearchSearchEng
   getTranslator() {
     return this.translator;
   }
+  getIndexTemplate() {
+    return this.indexTemplate;
+  }
 }
 
 const mock = new Mock();
@@ -50,6 +53,23 @@ jest.mock('./ElasticSearchSearchEngineIndexer', () => ({
     .mockImplementation(() => indexerMock),
 }));
 
+const customIndexTemplate = {
+  name: 'custom-index-template',
+  body: {
+    index_patterns: ['*'],
+    template: {
+      settings: {
+        number_of_shards: 1,
+      },
+      mappings: {
+        _source: {
+          enabled: false,
+        },
+      },
+    },
+  },
+};
+
 describe('ElasticSearchSearchEngine', () => {
   let testSearchEngine: ElasticSearchSearchEngine;
   let inspectableSearchEngine: ElasticSearchSearchEngineForTranslatorTests;
@@ -72,6 +92,20 @@ describe('ElasticSearchSearchEngine', () => {
     client = testSearchEngine['elasticSearchClient'];
   });
 
+  describe('custom index template', () => {
+    it('should not have custom template set as default', async () => {
+      expect(inspectableSearchEngine.getIndexTemplate()).toBeUndefined();
+    });
+
+    it('should set custom index template', async () => {
+      await inspectableSearchEngine.setIndexTemplate(customIndexTemplate);
+
+      expect(inspectableSearchEngine.getIndexTemplate()).toMatchObject(
+        customIndexTemplate,
+      );
+    });
+  });
+
   describe('queryTranslator', () => {
     beforeAll(() => {
       mock.clearAll();
@@ -760,6 +794,10 @@ describe('ElasticSearchSearchEngine', () => {
   });
 
   describe('indexer', () => {
+    beforeEach(async () => {
+      await testSearchEngine.setIndexTemplate(customIndexTemplate);
+    });
+
     it('should get indexer', async () => {
       const indexer = await testSearchEngine.getIndexer('test-index');
 
@@ -773,12 +811,38 @@ describe('ElasticSearchSearchEngine', () => {
           elasticSearchClient: client,
         }),
       );
+      expect(indexerMock.on).toHaveBeenCalledWith(
+        'finish',
+        expect.any(Function),
+      );
       expect(indexerMock.on).toHaveBeenCalledWith(
         'error',
         expect.any(Function),
       );
     });
 
+    describe('onFinish', () => {
+      let callback: Function;
+
+      beforeEach(async () => {
+        mock.clearAll();
+        await testSearchEngine.getIndexer('test-index');
+        callback = indexerMock.on.mock.calls[1][1];
+      });
+
+      it('should set provided index template on finish', async () => {
+        const indexTemplateSpy = jest.fn().mockReturnValue(customIndexTemplate);
+        mock.add(
+          { method: 'PUT', path: '/_index_template/custom-index-template' },
+          indexTemplateSpy,
+        );
+
+        await callback();
+
+        expect(indexTemplateSpy).toHaveBeenCalled();
+      });
+    });
+
     describe('onError', () => {
       let errorHandler: Function;
       const error = new Error('some error');

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

@@ -36,6 +36,24 @@ import { ElasticSearchSearchEngineIndexer } from './ElasticSearchSearchEngineInd
 
 export type { ElasticSearchClientOptions };
 
+/**
+ * Elasticsearch specific index template
+ * @public
+ */
+export type ElasticSearchCustomIndexTemplate = {
+  name: string;
+  body: ElasticSearchIndexTemplateBody;
+};
+
+/**
+ * Elasticsearch specific index template body
+ * @public
+ */
+export type ElasticSearchIndexTemplateBody = {
+  index_patterns: string[];
+  template: Record<string, any>;
+};
+
 /**
  * Search query that the elasticsearch engine understands.
  * @public
@@ -114,6 +132,7 @@ function isBlank(str: string) {
 export class ElasticSearchSearchEngine implements SearchEngine {
   private readonly elasticSearchClient: Client;
   private readonly highlightOptions: ElasticSearchHighlightConfig;
+  protected indexTemplate?: ElasticSearchCustomIndexTemplate;
 
   constructor(
     private readonly elasticSearchClientOptions: ElasticSearchClientOptions,
@@ -236,8 +255,13 @@ export class ElasticSearchSearchEngine implements SearchEngine {
     this.translator = translator;
   }
 
+  setIndexTemplate(template: ElasticSearchCustomIndexTemplate) {
+    this.indexTemplate = template;
+  }
+
   async getIndexer(type: string) {
     const alias = this.constructSearchAlias(type);
+
     const indexer = new ElasticSearchSearchEngineIndexer({
       type,
       indexPrefix: this.indexPrefix,
@@ -266,6 +290,20 @@ export class ElasticSearchSearchEngine implements SearchEngine {
       }
     });
 
+    indexer.on('finish', async () => {
+      // Set custom index template if set
+      if (this.indexTemplate) {
+        try {
+          await this.elasticSearchClient.indices.putIndexTemplate(
+            this.indexTemplate,
+          );
+          this.logger.info('Custom index template set');
+        } catch (error) {
+          this.logger.error(`Unable to set custom index template: ${error}`);
+        }
+      }
+    });
+
     return indexer;
   }