Elixir Client for Gremlin (Apache TinkerPop™)
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Latest commit d1cbfe8 Oct 19, 2018

README.md

Build Status License: MIT

Gremlex

An Elixir client for Apache TinkerPop™ aka Gremlin.

Gremlex does not support all functions (yet). It is pretty early on in it's development. But you can always use raw Gremlin queries by using Client.query("<Insert gremlin query>")

Installation

Install from Hex.pm:

def deps do
  [
    {:gremlex, "~> 0.1.1"}
  ]
end

Examples

Basic Usage

The two main modules that you'll want to use are Gremlex.Graph and Gremlex.Client.

Gremlex.Graph is the module that hosts all the functions needed to build a Gremlin query. The DSL is a simple set of functions that carries over a graph for every step. Once you've defined your query, you can simply call Gremlex.Client.query/1 to perform it.

iex(1)> alias Gremlex.Graph
Gremlex.Graph
iex(2)> alias Gremlex.Client
Gremlex.Client
iex(3)> Graph.g() |> Graph.v() |> Client.query
{:ok,
 [
   %Gremlex.Vertex{
     id: 1,
     label: "person",
     properties: %{age: [29], name: ["marko"]}
   }
 ]}

Gremlin Query to Gremlex

This gremlin query:

g.V().has("name","marko")
  .out("knows")
  .out("knows")
  .values("name")

Would translate in Gremlex to:

Graph.g()
|> Graph.v()
|> Graph.has("name", "marko")
|> Graph.out("knows")
|> Graph.out("knows")
|> Graph.values("name")
|> Client.query

Raw Queries

Client.query("""
  g.V().match(
    __.as("a").out("knows").as("b"),
    __.as("a").out("created").as("c"),
    __.as("b").out("created").as("c"),
    __.as("c").in("created").count().is(2)
  )
  .select("c").by("name")
""")

Configuration

You can configure Gremlex by adding the following to your config.exs:

config :gremlex,
  host: "127.0.0.1",
  port: 8182,
  path: "/gremlin",
  pool_size: 10,
  secure: false

Gremlex uses confex, so that you can easily define your configuration to use environment variables when it comes time to deploying. To do so, simply have the parameters that need to be dynamically read at run time set to {:SYSTEM, "ENV_VAR_NAME"}.

Parameters

  • host: Gremlin host to connect to (defaults to "127.0.0.1")
  • port: Port Gremlin is listening to on host (defaults to 8182)
  • path: Websocket path to Gremlin (defaults to "/gremlin")
  • pool_size: The number of connections to keep open in the pool (defaults to 10)
  • secure: Set to true to connect to a server with SSL enabled