Elastic
Elastic is an Elasticsearch client for the
Go programming language.
See the wiki for additional information about Elastic.
Releases
The release branches (e.g. release-branch.v3
) are actively being worked on and can break at any time. If you want to use stable versions of Elastic, please use the packages released via gopkg.in.
Here's the version matrix:
Example:
You have installed Elasticsearch 2.1.1 and want to use Elastic. As listed above, you should use Elastic 3.0. So you first install the stable release of Elastic 3.0 from gopkg.in.
$ go get gopkg.in/olivere/elastic.v3
You then import it with this import path:
import "gopkg.in/olivere/elastic.v3"
Elastic 3.0
Elastic 3.0 targets Elasticsearch 2.0 and later. Elasticsearch 2.0.0 was released on 28th October 2015.
Notice that there are a lot of breaking changes in Elasticsearch 2.0 and we used this as an opportunity to clean up and refactor Elastic as well.
Elastic 2.0
Elastic 2.0 targets Elasticsearch 1.x and is published via gopkg.in/olivere/elastic.v2
.
Elastic 1.0
Elastic 1.0 is deprecated. You should really update Elasticsearch and Elastic
to a recent version.
However, if you cannot update for some reason, don't worry. Version 1.0 is
still available. All you need to do is go-get it and change your import path
as described above.
Status
We use Elastic in production since 2012. Elastic is stable but the API changes
now and then. We strive for API compatibility.
However, Elasticsearch sometimes introduces breaking changes
and we sometimes have to adapt.
Having said that, there have been no big API changes that required you
to rewrite your application big time. More often than not it's renaming APIs
and adding/removing features so that Elastic is in sync with Elasticsearch.
Elastic has been used in production with the following Elasticsearch versions:
0.90, 1.0-1.7. Furthermore, we use Travis CI
to test Elastic with the most recent versions of Elasticsearch and Go.
See the .travis.yml
file for the exact matrix and Travis
for the results.
Elasticsearch has quite a few features. Most of them are implemented
by Elastic. I add features and APIs as required. It's straightforward
to implement missing pieces. I'm accepting pull requests :-)
Having said that, I hope you find the project useful.
Getting Started
The first thing you do is to create a Client. The client connects to Elasticsearch on http://127.0.0.1:9200
by default.
You typically create one client for your app. Here's a complete example of
creating a client, creating an index, adding a document, executing a search etc.
client, err := elastic.NewClient()
if err != nil {
panic(err)
}
_, err = client.CreateIndex("twitter").Do()
if err != nil {
panic(err)
}
tweet := Tweet{User: "olivere", Message: "Take Five"}
_, err = client.Index().
Index("twitter").
Type("tweet").
Id("1").
BodyJson(tweet).
Refresh(true).
Do()
if err != nil {
panic(err)
}
termQuery := elastic.NewTermQuery("user", "olivere")
searchResult, err := client.Search().
Index("twitter").
Query(termQuery).
Sort("user", true).
From(0).Size(10).
Pretty(true).
Do()
if err != nil {
panic(err)
}
fmt.Printf("Query took %d milliseconds\n", searchResult.TookInMillis)
var ttyp Tweet
for _, item := range searchResult.Each(reflect.TypeOf(ttyp)) {
if t, ok := item.(Tweet); ok {
fmt.Printf("Tweet by %s: %s\n", t.User, t.Message)
}
}
fmt.Printf("Found a total of %d tweets\n", searchResult.TotalHits())
if searchResult.Hits.TotalHits > 0 {
fmt.Printf("Found a total of %d tweets\n", searchResult.Hits.TotalHits)
for _, hit := range searchResult.Hits.Hits {
var t Tweet
err := json.Unmarshal(*hit.Source, &t)
if err != nil {
panic(err)
}
fmt.Printf("Tweet by %s: %s\n", t.User, t.Message)
}
} else {
fmt.Print("Found no tweets\n")
}
_, err = client.DeleteIndex("twitter").Do()
if err != nil {
panic(err)
}
Here's a link to a complete working example.
See the wiki for more details.
API Status
Document APIs
Search APIs
Aggregations
Indices APIs
cat APIs
The cat APIs are not implemented as of now. We think they are better suited for operating with Elasticsearch on the command line.
Cluster APIs
Query DSL
Modules
Sorting
Scan
Scrolling through documents (e.g. search_type=scan
) are implemented via
the Scroll
and Scan
services. The ClearScroll
API is implemented as well.
How to contribute
Read the contribution guidelines.
Credits
Thanks a lot for the great folks working hard on
Elasticsearch
and
Go.
Elastic uses portions of the
uritemplates library
by Joshua Tacoma and
backoff by Cenk Altı.
LICENSE
MIT-LICENSE. See LICENSE
or the LICENSE file provided in the repository for details.