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, "~> 0.4.2"}
  ]
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,
  max_overflow: 10,
  secure: false,
  ping_delay: 60_000,
  opts: []

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
• ping_delay: Delay in milliseconds to send a pong frame to the server. If 0, then a pong frame won't be scheduled. (defaults to 0)
• opts: A keyword list of options for customizing the webSocket connection, such as timeouts, SSL settings, or proxy configurations. This corresponds to the same option in Mint.WebSocket options

Contributing

$ git clone https://github.com/coingaming/gremlex.git
$ cd gremlex
$ ./scripts/test.sh