Getting Started With Elasticsearch REST APIs

One of the many best things about Elasticsearch is it's  REST API that allows to create, maintain and query the index data in multiple ways. 

In this blog I will try to provide a summary of the some important API calls that you should get familiar with as you get started with Elasticsearch, and will add some examples with respective cURL commands.

The API examples detailed below are Document API, Search API, Indices API and cat API.

Document API

This API is used for handling documents in Elasticsearch.
Using these APIs, you can create documents in an index, update them, move them to different index, or even remove them.  

Example :

1. Add a document : Add a document to an existing or a new index.

jatingupta@jatingupta:~$ curl -XPUT 'localhost:9200/movies/nolan/1?pretty' -H 'Content-Type: application/json' -d'{ "Name" : "Memento" }'
jatingupta@jatingupta:~$ curl -XPUT 'localhost:9200/movies/nolan/2?pretty' -H 'Content-Type: application/json' -d'{ "Name" : "Inception" }'

2. Delete a document : Delete a document from an existing index.

jatingupta@jatingupta:~$ curl -XDELETE 'localhost:9200/movies/nolan/1?pretty'

3. Reindex : Change the index.

jatingupta@jatingupta:~$ curl -XPOST 'localhost:9200/_reindex?pretty' -H 'Content-Type: application/json' -d'{ "source" :{ "index": "old_index" },"dest": { "index": "new_index"  } } '

Search API

1. Search : Search for a document in an existing index.

jatingupta@jatingupta:~$ curl -XGET "localhost:9200/movies/nolan/_search?q=Name:Memento&pretty"

2. Count : Count the number of matches for the query.

jatingupta@jatingupta:~$ curl -XGET "localhost:9200/movies/nolan/_count?q=Name:Memento&pretty"

3. Validate : Validate a query without executing it.

jatingupta@jatingupta:~$ curl -XGET "localhost:9200/movies/nolan/_validate?q=Name:Memento&pretty"

Indices API

1. Create : Create a new index

jatingupta@jatingupta:~$ curl -XPUT "localhost:9200/books?pretty -H'Content-Type:application/json'"

2. Delete : Delete an index

jatingupta@jatingupta:~$ curl -XDELETE "localhost:9200/books?pretty"

3. Map : Add a new type to existing mapping

jatingupta@jatingupta:~$ curl -XPUT  'localhost:9200/employee/_mapping/user?pretty' -H 'Content-Type: application/json' -d' {   "properties": { "name": {  "type": "text"  }  } }  '

jatingupta@jatingupta:~$ curl -XGET "localhost:9200/_cat/indices?v"

jatingupta@jatingupta:~$ curl -XGET "localhost:9200/_cat/health?v&pretty"

jatingupta@jatingupta:~$ curl -XGET "localhost:9200/_cat/nodes?v&pretty"