add support for temp reindexing

Author: ThomasKranitsas

config/default.js

@@ -40,7 +40,8 @@ module.exports = {
     API_VERSION: process.env.ES_API_VERSION || '6.8',
     ES_INDEX: process.env.ES_INDEX || 'challenge',
     ES_TYPE: process.env.ES_TYPE || '_doc', // ES 6.x accepts only 1 Type per index and it's mandatory to define it
-    ES_REFRESH: process.env.ES_REFRESH || 'true'
+    ES_REFRESH: process.env.ES_REFRESH || 'true',
+    TEMP_REINDEXING: process.env.TEMP_REINDEXING || true // if true, it won't delete the existing index when reindexing data
   },
 
   // in bytes

src/scripts/update-es-mappings.js

@@ -33,9 +33,22 @@ function createIndex (indexName) {
 }
 
 async function updateMappings () {
+  const tempReindexing = config.get('ES.TEMP_REINDEXING')
   let indexName = config.get('ES.ES_INDEX')
   let newIndexName = `${indexName}_tmp_dont_use_for_querying`
 
+  if (tempReindexing) {
+    try {
+      logger.info(`Attemp to remove temporary index ${newIndexName}`)
+      await esClient.indices.delete({
+        index: newIndexName
+      })
+      await sleep(500)
+    } catch (e) {
+      logger.info(`Index ${newIndexName} does not exist`)
+    }
+  }
+
   await createIndex(newIndexName)
   await sleep(500)
   logger.info(`Reindexing from ${indexName} to ${newIndexName}`)
@@ -47,6 +60,10 @@ async function updateMappings () {
     waitForCompletion: true
   })
 
+  if (tempReindexing) {
+    return
+  }
+
   logger.warn(`Deleting ${indexName}. If script crashes after this point data may be lost and a recreation of index will be required.`)
 
   await esClient.indices.delete({