ReIndex Elasticsearch index from one to another on Jenkinsfile. Example transfer happens from `products_v1` to `products_v2` index

ReIndexJenkinsfile

#!/usr/bin/env groovy

node {
    stage('checkout') {
        checkout scm
    }
    stage("Reindex") {
        String esHost = params.esHost //example: localhost:9200
        String oldIndexVersion = params.oldIndexVersion //example: v1
        String newIndexVersion = params.newIndexVersion //example: v2
        def productIndices = sh(script: "curl -f -XGET \"$esHost/products_*\"", returnStdout: true)
        def allIndexNames = new groovy.json.JsonSlurper().parseText(productIndices).keySet()

        def oldIndexNames = allIndexNames.findAll { idx -> idx.endsWith(oldIndexVersion) }
        def newIndexNames = oldIndexNames.collect { idx -> idx.replaceAll(oldIndexVersion, newIndexVersion)}
        if (!allIndexNames.containsAll(newIndexNames)) {
            println("All indices:" + allIndexNames)
            println("New indices:" + newIndexNames)
            error "All new indices for '${newIndexVersion}' must be created before reindexing on ${esHost}!"
        }

        for (idx in oldIndexNames) {
            String newIdx = idx.replaceAll(oldIndexVersion, newIndexVersion)
            println("Reindexing from ${idx} to ${newIdx}")
            sh """
                curl -f -XPOST "$esHost/_reindex" -H 'Content-Type: application/json' -d'
                 {
                   "source": {
                     "index": "'${idx}'"
                   },
                   "dest": {
                     "index": "'${newIdx}'"
                   }
                 }'
            """
        }
    }
}