Cl-Elastic - Elasticsearch client for Common Lisp

Motivation

This project is supposed to be a simple interface for Elasticsearch. The emphasis is on simple, i.e. this is not supposed to be a DSL on top of another DSL. You should be able go to the Elasticsearch docs and translate that immediatly into working code. If you are looking for a DSL checkout the section about other work.

Installation

Update: 29.11.2019

The library is now in quicklisp. You can now simply do (ql:quicklisp :cl-elastic) to load cl-elastic.

Usage

(ql:quicklisp :cl-elastic)
(use :cl-elastic)

(defvar *client* (make-instance '<client> :endpoint "http://localhost:9200"))

;; creates an index named `elasticsearch-test`
(send-request *client* '("elasticsearch-test") :method :put)

You can enable keyword arguments which lets you use keywords as keys in hashtable and parameter plists as well as uri construction. The transformation is always to lowercase.

(setq *enable-keywords* t)
(send-request *client* '(:elasticsearch-test) :method :put)

The library uses the yason library under the hood to map between lisp objects and JSON. As hashtables are therefore ubiquitous for JSON construction the library also exports a simple reader syntax for literal hashmap construction. The syntax is #{key1 value1 key2 value2 ...}. For the enabling and disabling of the syntax the library uses named-readtables.

(in-readtable hashtable-syntax)

(defvar foo "bar")
;; creates a hashmap with ("bar" 1) and ("foo" 2) as key/value pairs
#{foo 1 "foo" 2}

(in-readtable :standard)

For the remaining examples we are assuming that *enable-keywords* is set to true and the above hashtable syntax is enabled. The following examples assume that you are using Elasticsearch version 7.0.0 or above, otherwise you might need to adapt the index settings.

;; create a index with a test field of type text
(send-request *client* :elasticsearch-test :method :put 
              :data #{:settings #{:number_of_shards 1}
                      :mappings #{:properties #{:test #{:type "text"}}}})

;; create a document with id 3
(send-request *client* '(:elasticsearch-test :_doc 3) :method :put
              :data #{:test "toto"})
              
;; find a document by id
(send-request *client* '(:elasticsearch-test :_doc 3) :method :get)

;; search for something
(send-request *client* '(:elasticsearch-test :_search) :method :get
              :data #{:query #{:term #{:test "toto"}}})

;; delete the document
(send-request *client* '(:elasticsearch-test :_doc 3) :method :delete)

;; for bulk requests you can pass a list of operations as data
(send-request *client* :_bulk :method :post
              :data (list
                     #{:index #{:_index :elasticsearch-test :_id 3}}
                     #{:test "foo"}
                     #{:index #{:_index :elasticsearch-test :_id 2}}
                     #{:test "bar"}
                     #{:delete #{:_index :elasticsearch-test :_id 3}}))

Other work

There are a couple of other clients, although non of them are in quicklisp:
clesc
cl-elasticsearch
eclastic

Todo

• Add authentication
• Add async indexing with cl-async.

Author

• Finn Völkel ([email protected])

Licence

MIT Licence

Copyright

Copyright (c) 2019 Finn Völkel ([email protected])