OMQ::Transport::WebSocket

ZeroMQ-over-WebSocket transport for OMQ. Implements ZeroMQ RFC 45 (ZWS 2.0).

Adds ws:// and wss:// schemes to OMQ. Both register at require time. No other OMQ code change required.

Install

gem "omq",           "~> 0.28"
gem "omq-websocket", "~> 0.1"

Use

require "omq"
require "omq/websocket"

# Server
pull = OMQ::PULL.new
pull.bind("ws://127.0.0.1:5555")

# Client
push = OMQ::PUSH.connect("ws://127.0.0.1:5555")
push.send("hello")

TLS (wss://)

ctx = OpenSSL::SSL::SSLContext.new
ctx.cert = OpenSSL::X509::Certificate.new(File.read("cert.pem"))
ctx.key  = OpenSSL::PKey::RSA.new(File.read("key.pem"))

pull = OMQ::PULL.new
pull.tls_context = ctx
pull.bind("wss://127.0.0.1:5556")

Mechanism

By default the client offers ZWS2.0/NULL then ZWS2.0. The server picks the first one it accepts. Override via:

sock.ws_subprotocols = %w[ZWS2.0]   # force no-mechanism

Path

Defaults to /. Override via sock.ws_path = "/zeromq". Listener returns 404 for any other path.

Wire protocol

Per RFC 45, each ZeroMQ frame maps to one WebSocket binary message: a single FLAG byte (0x00 final, 0x01 more, 0x02 command) followed by the frame body. No 64-byte ZMTP greeting. Mechanism negotiation happens via Sec-WebSocket-Protocol during the HTTP upgrade. See lib/omq/transport/websocket/codec.rb.

License

ISC.