Machine Learning & Big Data Blog

ElasticSearch Commands Cheat Sheet

ITIL 4
2 minute read
Walker Rowe

Here we show some of the most common ElasticSearch commands using curl. ElasticSearch is sometimes complicated. So here we make it simple.

(This article is part of our ElasticSearch Guide. Use the right-hand menu to navigate.)

delete index

Below the index is named samples.

curl -X DELETE 'http://localhost:9200/samples'

list all indexes

curl -X GET 'http://localhost:9200/_cat/indices?v'

list all docs in index

curl -X GET 'http://localhost:9200/sample/_search'

query using URL parameters

Here we use Lucene query format to write q=school:Harvard.

curl -X GET http://localhost:9200/samples/_search?q=school:Harvard

Query with JSON aka Elasticsearch Query DSL

You can query using parameters on the URL. But you can also use JSON, as shown in the next example. JSON would be easier to read and debug when you have a complex query than one giant string of URL parameters.

curl -XGET --header 'Content-Type: application/json' http://localhost:9200/samples/_search -d '{
"query" : {
"match" : { "school": "Harvard" }
}
}'

list index mapping

All Elasticsearch fields are indexes. So this lists all fields and their types in an index.

curl -X GET http://localhost:9200/samples

Add Data

curl -XPUT --header 'Content-Type: application/json' http://localhost:9200/samples/_doc/1 -d '{
"school" : "Harvard"			
}'

Update Doc

Here is how to add fields to an existing document. First we create a new one. Then we update it.

 
curl -XPUT --header 'Content-Type: application/json' http://localhost:9200/samples/_doc/2 -d '
{
"school": "Clemson"
}'
curl -XPOST --header 'Content-Type: application/json' http://localhost:9200/samples/_doc/2/_update -d '{
"doc" : {
"students": 50000}
}'

backup index

curl -XPOST --header 'Content-Type: application/json' http://localhost:9200/_reindex -d '{
"source": {
"index": "samples"
},
"dest": {
"index": "samples_backup"
}
}'

Bulk load data in JSON format

export pwd="elastic:"
curl --user $pwd  -H 'Content-Type: application/x-ndjson' -XPOST 'https://58571402f5464923883e7be42a037917.eu-central-1.aws.cloud.es.io:9243/0/_bulk?pretty' --data-binary @<file>

Show cluster health

curl --user $pwd  -H 'Content-Type: application/json' -XGET https://58571402f5464923883e7be42a037917.eu-central-1.aws.cloud.es.io:9243/_cluster/health?pretty

Aggregation and Bucket Aggregation

For an nginx web server this produces web hit counts by user city:

curl -XGET --user $pwd --header 'Content-Type: application/json'  https://58571402f5464923883e7be42a037917.eu-central-1.aws.cloud.es.io:9243/logstash/_search?pretty -d '{
"aggs": {
"cityName": {
"terms": {
"field": "geoip.city_name.keyword",
"size": 50
}
}
}
}
'

This expands that to product response code count by city in an nginx web server log

curl -XGET --user $pwd --header 'Content-Type: application/json'  https://58571402f5464923883e7be42a037917.eu-central-1.aws.cloud.es.io:9243/logstash/_search?pretty -d '{
"aggs": {
"city": {
"terms": {
"field": "geoip.city_name.keyword"
},
"aggs": {
"responses": {
"terms": {
"field": "response"
}
}
}
},
"responses": {
"terms": {
"field": "response"
}
}
}
}'

Using ElasticSearch with Basic Authentication

If you have turned on security with ElasticSearch then you need to supply the user and password like shown below to every curl command:

curl -X GET 'http://localhost:9200/_cat/indices?v' -u elastic:(password)

Pretty Print

Add ?pretty=true to any search to pretty print the JSON. Like this:

 curl -X GET 'http://localhost:9200/(index)/_search'?pretty=true

To query and return only certain fields

To return only certain fields put them into the _source array:

GET filebeat-7.6.2-2020.05.05-000001/_search
{
"_source": ["suricata.eve.timestamp","source.geo.region_name","event.created"],
"query":      {
"match" : { "source.geo.country_iso_code": "GR" }
}
}

To Query by Date

When the field is of type date you can use date math, like this:

GET filebeat-7.6.2-2020.05.05-000001/_search
{
"query": {
"range" : {
"event.created": {
"gte" : "now-7d/d"
}
}
}
}

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About the author

Walker Rowe

Walker Rowe is an American freelancer tech writer and programmer living in Cyprus. He writes tutorials on analytics and big data and specializes in documenting SDKs and APIs. He is the founder of the Hypatia Academy Cyprus, an online school to teach secondary school children programming. You can find Walker here and here.