ZeroMQ is a simple and robust asynchronous messaging layer.1 Unfortunately, using it with Clojure is far from simple. The steps below are the magic key that worked for me:
- Starting out nice and slow, install the core zmq libraries and command line tools with homebrew:2
brew install zmq- With ZMQ installed, you’re ready to start building jzmq, the Java bindings. You’ll need to patch the homebrew formula for pkg-config, as jzmq requires the latest-and-greatest to build correctly3
brew edit pkg-configrequire 'formula'
class PkgConfig <Formula
homepage 'http://pkgconfig.freedesktop.org'
url 'http://pkgconfig.freedesktop.org/releases/pkg-config-0.25.tar.gz'
md5 'a3270bab3f4b69b7dc6dbdacbcae9745'
def install
paths=%W[#{HOMEBREW_PREFIX}/lib/pkgconfig /usr/local/lib/pkgconfig /usr/lib/pkgconfig /usr/X11/lib/pkgconfig].uniq
system "./configure", "--with-pc-path=#{paths*':'}", "--disable-debug", "--prefix=#{prefix}"
system "make install"
end
end- At this point, you’ll need to copy one of the essential pkg-config files into a location that jzmq’s build tools can find.4
sudo cp /usr/local/Cellar/pkg-config/0.25/share/aclocal/pkg.m4 /usr/share/aclocal/pkg.m4- Now we’re ready to build jzmq. This will build the dylib you’ll need to actually use the bindings, and places it in
/usr/local/lib.5
git clone git://github.com/zeromq/jzmq.git
cd jzmq
./autogen.sh
./configure
make
sudo make install- Getting closer! We’ll need the zmq.jar file produced during the build, so copy that into your project’s lib directory:6
cp ./src/zmq.jar /path/to/my/project/lib/zmq.jar- Now we can actually start setting up Clojure for ZMQ. Edit your leiningen project.clj file:
(defproject my-project "1.0.0-SNAPSHOT"
:description "FIXME: write"
:dependencies [[org.clojure/clojure "1.2.0"]
[org.clojure/clojure-contrib "1.2.0"]
[org.clojars.mikejs/clojure-zmq "2.0.7-SNAPSHOT"]]
:dev-dependencies [[swank-clojure "1.2.1"]]
; This sets the 'java.library.path' property
; so Java can find the ZeroMQ dylib
:native-path "/usr/local/lib")- Collect the leiningen dependencies:
lein deps- Start your swank server:
lein swank- Bask in the results with the canonical example:
(ns my-project.core
(:use [org.zeromq.clojure :as zmq]))
(defn- string-to-bytes [s] (.getBytes s))
(defn- bytes-to-string [b] (String. b))
(defn test-zmq []
(let [ctx (zmq/make-context 1)
socket (zmq/make-socket ctx zmq/+upstream+)]
(zmq/connect socket "tcp://127.0.0.1:5555")
(while true
(println (bytes-to-string (zmq/recv socket))))))This process is definitely rough around the edges, but I hope it helps you get started quickly!
-
Read this excellent ZeroMQ introduction if you’re not familiar with ZMQ. You’ll love it. ↩
-
This guide is EXTREMELY
brew-centric. If you’re running OS X, you should be using homebrew for dependency management. ↩ -
There’s an open ticked to update pkg-config in the homebrew backlog, so this may be unnecessary soon. ↩
-
This step should either be taken care of by homebrew, or by jzmq’s
./configure, but I wasn’t able to get it working. Please leave a note if you know how I could resolve this step! ↩ -
This is another step that seems problematic. It would be best to just install the dylib straight into OS X’s Java extensions directory. Again, please leave a comment if you can help! ↩
-
Another hacky step. I gather it’s possible to build jzmq with leiningen, but the
native-depsdependency doesn’t seem to work with lein 1.3.0. Suggestions? ↩
