1st positional parameter: ES source. 2nd positional argument: ES target. 3rd positional argument: Action (backup/migrate)

elastigrate.sh

#!/usr/bin/bash
dependency=()
command -v elasticdump > /dev/null || dependency+="elasticdump "
command -v curl > /dev/null || dependency+="curl "
command -v jq > /dev/null || dependency+="jq "
if [[ ${#dependency[@]} -gt 0 ]]; then
	echo "Missing dependency: ${dependency[@]}"
	exit 1
fi

if [[ -z $1 ]] || [[ -z $2 ]] || [[ -z $3 ]]; then
	echo "Please set these variables... "
	echo "ES source as the 1st parameter"
	echo "ES target as the 2nd parameter"
	echo "ES action as the 3rd parameter"
	echo "./elasticdump.sh source:9092 dest:9092 backup/migrate"
	exit 1
fi

for index in $(curl -XGET $1/_cat/indices -s | awk '{print $3}'); do
	if [[ $3 == "migrate" ]]; then
		elasticdump --input=$1/${index} --output=$2/${index} --type=analyzer
		elasticdump --input=$1/${index} --output=$2/${index} --type=mapping
		elasticdump --input=$1/${index} --output=$2/${index} --type=data
	elif [[ $3 == "backup" ]]; then
		elasticdump --input=$1/${index} --output=${index}.analyzer.json --type=analyzer
		elasticdump --input=$1/${index} --output=${index}.mapping.json --type=mapping
		elasticdump --input=$1/${index} --output=${index}.data.json --type=data
	fi
done

How to use

./elastigrate.sh source.9092 target:9092 migrate  # migrate the data from source to target
./elastigrate.sh source.9092 target:9092 backup  # backup the indexes from source into local JSON file 

Thanks to elastidump developer