Natsex

[

Elixir client for NATS

Features

• Pub/Sub
• Request/Reply
• Queueing
• Keep-alive mechanism (via ping/pong)
• Reconnection logic
• TLS support
• Raw NATS Streaming support

Installation

The package can be installed by adding natsex to your list of dependencies in mix.exs:

def deps do
  [
    {:natsex, "~> 0.9.1"}
  ]
end

Usage

# connects with default params, host - "localhost", port - 4222
iex(1)> {:ok, pid} = Natsex.start_link()
{:ok, #PID<0.195.0>}

# or connects on custom port with credentials
iex(1)> {:ok, pid} = Natsex.start_link(config: %{host: "localhost", port: 4567, user: "admin", pass: "12345"})
{:ok, #PID<0.195.0>}

iex(2)> Natsex.subscribe(pid, "telegram.user.notifications", self())
"13b2d0cd-9dba-43b6-bb5d-288d48346ff4"

iex(3)> flush
{:natsex_message,
 {"telegram.user.notifications", "13b2d0cd-9dba-43b6-bb5d-288d48346ff4", nil},
 "Good news, everyone!"}
:ok

# sent a message and waits a response, aka "Request-Reply"
iex(4)> Natsex.request(pid, "questions", "sup?")
{:ok, "response"}

iex(5)> Natsex.stop(pid)
:ok

TLS connection

# connects with tls
iex(1)> Natsex.start_link(config: %{tls_required: true})
{:ok, #PID<0.195.0>}

# connects with client cert
iex(1)> Natsex.start_link(config: %{tls_required: true,
                                    cert_path: Path.expand("./cert.crt"),
                                    cert_key_path: Path.expand("./client.key")})
{:ok, #PID<0.195.0>}

Benchmarking

TODO

• String config (nats://user:password@server:port)
• Set the Number of Reconnect Attempts
• Cache outgoing data
• Avoiding the Thundering Herd
• Buffering Messages During Reconnect Attempts
• Setting the Connection Name
• Limit Outgoing Pings
• Cluster support