resttogremlin

This is a gremlin client written in go with a wrapper to expose gremlin requests to rest client in easiest way possible. This connects to any graph database that supports TinkerPop3 using Go and also opens a http server for client communication. TinkerPop3 uses Gremlin Server to communicate with clients using either WebSockets or REST API. Here we talk to Gremlin Server using WebSockets. There is handler_config which helps you to define handlers and the post form parameters and corresponding gremlin script.

Installing the server (TBD: more explanation)

go get github.com/sinha-abhishek/resttogremlin

Defining api end points (TBD: admin console to define new APIs)

• open handler_config.json
• Let's say you want to expose an API called create_vertex with property uid with value being user_id passed by client
• add this to json array

"create_vertex" : {
		"query" : "graph.addVertex(\"user\").property('uid',XUID)",
		"bindings" : {
			"XUID" : "uid"
		}
	},

• Save this file and start the server doing go build and running the executable. You can set the port number to run in server_conf.json.
• This will now provide a api way to create a vertex with user id
• To use this api you can send curl -X POST -vid 'uid=1' -H 'Content-Type:application/x-www-form-urlencoded' http://<server:port>/gremlin/create_vertex

Using this as gremlin client library

If you do not want to use it as a rest server but as a gremlin library for your go project. You can do the following

• Include the project in your go path by either cloning or go get
• Creating a Cient client := gremlin.NewClient("<array of strings with each string pointing to a gremlin server url>" For example

hosts := [1]string {"localhost:8182"}
client := gremlin.NewClient(hosts)

• client maintains a connection pool of all gremlin websockets.
• To send a request create a gremlin request you need to create GremlinRequest object and use setQuery to defing your gremlin query. You can define bindings using SetBindings

gr := client.NewGremlinRequest()
query := "g.V().has('uid',XUID)"
bindings := make(map[string]interface{})
bindings['XUID'] = 1
  gr.SetQuery(query)
  gr.AddBindings(bindings)
  	response, err2 := client.SendRequest(gr)
  	if err2 != nil {
  		//handle error
  	}

• There are also other methods like reading a gremlin request query from a file. Please see gremlinrequest.go
• Response is the result returned by gremlin server