Migrate all indexes of Elastic Search from a cluster to another - It has less limirations then reindex when runinng with differnt ES versions

migrate-data.sh

#!/bin/bash
# See https://gist.github.com/db1af03d007d2f64a44ff22f4633fe74 for more info

# This script backup data from a ES instance to disk and create a xz archive with the command to restore it
# You need to have jq ( https://stedolan.github.io/jq/ ) and elasticdump ( https://www.npmjs.com/package/elasticdump ) installed


# source ES instance
DEFAULT_ESR='http://source:9200' # Edit this
ESR=${1:-$DEFAULT_ESR} # Or just use $1 to add the Elastic Search url

# source ES instance
DEFAULT_ESW='http://localhost:9200' # Edit this
ESW=${2:-$DEFAULT_ESW} # Or just use $2 to add the Elastic Search url

# Tune this reg expression to filter the indexes you want to backup
DEFAULT_REGEX='.*'
REGEX=${3:-$DEFAULT_REGEX}

DEFAULT_CMD='elasticdump' # You can use your own clone of elasticdump. Ex: 'Ex: '/Users/youruser/my-projects/elasticsearch-dump/bin/elasticdump'
CMD=${4:-$DEFAULT_CMD}

duplicate_index() {
    local in=$1
    local out=$2
    local index=$3
    shift
    shift
    shift
    for i; do
      echo " ----> Duplicating '${in}/${index}' ('$i')"
      $CMD \
        --limit=9999 \
        --input=${in}/${index} \
        --output=${out}/${index} \
        --type=$i
    done;
}

indexes=$(curl $ESR/_aliases?pretty=1 | jq --raw-output 'keys | .[]')

echo "$indexes" | while read -r current_index; do
  if [[ $current_index =~ $REGEX ]]
  then
    echo " --> Coping '$current_index'";
    duplicate_index "$ESR" "$ESW" "$current_index" analyzer settings mapping alias data
  else
    echo " !!--> Skipping '$current_index' that does not match the REGEX $REGEX";
  fi
done;