Elasticsearch

Introduction

ES provides a REST interface to read and write data. In this repository I'll list a couple of snippet or information to start to play with ES.

Install with docker

We'll use ES inside a docker machine.

First of all pull docker image:

> docker pull docker.elastic.co/elasticsearch/elasticsearch:6.2.4

Second, run docker:

> docker run -p 9300:9300 -p 9200:9200 docker.elastic.co/elasticsearch/elasticsearch:6.2.4

Now start with CRUD operations

Create new index and properties mapping.

Request

An index is created just adding a resource.

>  PUT http://localhost:9200/indice
>  {
>   "mappings": {
>     <cose che mappo>: {
>       "properties": {
>         <chiave>: {
>           "type": <tipo della chiave>
>         }
>       }
>     }
>   }
>  }

Response

< {
<     "acknowledged": true,
<     "shards_acknowledged": true,
<     "index": "indice"
< }

See indexes in browser

Request

> http://localhost:9200/_cat/indices

Response

yellow open indice Fly0K1RcSRumG86Xr-VYXQ 5 1 0 0 1.1kb 1.1kb green open .monitoring-es-6-2018.05.29 rtrWxymcRe-p9SogkIC32w 1 0 318 55 392.3kb 392.3kb

Create new record

Request

> PUT http://localhost:9200/indice/_doc/1
> {
>  "ip_addr": "192.168.1.1"
> }

Response

< {
<     "_index": "indice",
<     "_type": "_doc",
<     "_id": "1",
<     "_version": 1,
<     "result": "created",
<     "_shards": {
<         "total": 2,
<         "successful": 1,
<         "failed": 0
<     },
<     "_seq_no": 0,
<     "_primary_term": 1
< }

Get record

Request

> GET http://localhost:9200/indice/_doc/2

Response

< {
<     "_index": "indice",
<     "_type": "_doc",
<     "_id": "2",
<     "_version": 6,
<     "found": true,
<     "_source": {
<         "ip_addr": "192.168.1.2"
<     }
< }

Search inside index

Request

> Content-type: application/json
> GET http://localhost:9200/indice/_search/
> {
>   "query": {
>     "term": {
>       "ip_addr":"192.168.2.2/16"
>       }
>   }
> }

Response

< { 
<   "took" : 3,
<   "timed_out" : false,
<   "hits" : {
<      "total" : 1,
<      "max_score" : 1,
<      "hits" : [
<         {
<            "_score" : 1,
<            "_source" : {
<               "ip_addr" : "192.168.2.2"
<            },
<            "_type" : "_doc",
<            "_id" : "2",
<            "_index" : "indice"
<         }
<      ]
<   },
<   "_shards" : {
<      "failed" : 0,
<      "total" : 5,
<      "successful" : 5,
<      "skipped" : 0
<   }
< }

Multiple search

Request

> GET index/type/_search
> {
>   "query": {
>     "bool": {
>       "must": [
>         {
>           "match": {
>             "path.to.some.field.keyword": "value"
>           }
>         },
>         {
>           "match": {
>             "path.to.another.field.keyword": "another value"
>           }
>         }
>       ]
>     }
>   }
> }

Pagination

Limit and offset

> GET index/type/_search?size=10
> GET index/type/_search?size=10&from=42