Demonstration of how to rename an ElasticSearch index using the Index Clone API, introduced in ES 7.4. This is the cUrl based version. See here for details: https://stackoverflow.com/a/59397746/2887657 .

rename_es_index.sh

source_index=source_index
target_index=target_index
elastic_search_server=elasticsearch:9200


# Make sure the source index is actually open
curl  -X POST  "${elastic_search_server}/${source_index}/_open"

# Put the source index in read-only mode
curl  -X PUT  "${elastic_search_server}/${source_index}/_settings"  \
-H 'Content-Type: application/json' -d'{
    "settings": {
        "index.blocks.write": "true"
    }
}'

# Clone the source index to the target name, and set the target to read-write mode
curl  -X POST  "${elastic_search_server}/${source_index}/_clone/${target_index}"  \
-H 'Content-Type: application/json'  -d'{
    "settings": {
        "index.blocks.write": null 
    }
}'

# Wait until the target index is green;
# it should usually be fast (assuming your filesystem supports hard links).
curl  -X GET  "${elastic_search_server}/_cluster/health/${target_index}?wait_for_status=green&timeout=30s"

# If it appears to be taking too much time for the cluster to get back to green,
# the following requests might help you identify eventual outstanding issues (if any)
curl  -X GET  "${elastic_search_server}/_cat/indices/${target_index}"
curl  -X GET  "${elastic_search_server}/_cat/recovery/${target_index}"
curl  -X GET  "${elastic_search_server}/_cluster/allocation/explain"

# Delete the source index
curl  -X DELETE  "${elastic_search_server}/${source_index}"