Installing the socket.io chat example on node.js + socket.io using git and npm

Yesterday was the first JavaScript Hack Night at the Stamford Innovation Center, and I proposed to the group we try setting up push notifications using node.js and socket.io. We had a heck of a time getting it up and running, even having referenced installation articles and google groups about the matter, so I’m posting my findings here.

I feel compelled to point out, though, our friend Joe got a node.js example site up and running using the node windows installer and Microsoft WebMatrix in a matter of a few minutes. However, I don’t believe he had socket.io running.

Symptom?

After installing node, npm and getting socket.io from git, running “node app.js” for the socket.io chat example kept producing the following error:

module.js:340
    throw err;
          ^
Error: Cannot find module 'socket.io-client'
    at Function.Module._resolveFilename (module.js:338:15)
    at Function.Module._load (module.js:280:25)
    at Module.require (module.js:362:17)
    at require (module.js:378:17)
    ...

Problem?

We were failing to install socket.io dependencies. The following combination of versions eventually worked for me:

node 0.8.7
npm 1.1.49
socket.io 0.9.10

Step-by-Step Installation

Dependencies, Git and working directory

I was working with a clean Ubuntu install, so I had to first run the following:

sudo apt-get install g++ curl libssl-dev apache2-utils git-core
cd ~
mkdir node-socket.io
cd ~/node-socket.io

Installing Node

Get node.js. This may take a while to build, depending on your system:

cd ~/node-socket.io
git clone https://github.com/joyent/node.git
mv node node-0.8.7
cd node-0.8.7
git checkout v0.8.7
./configure
make
sudo make install

Installing npm

Grab a copy of npm; we may be able to grab a newer one:

cd ~/node-socket.io
git clone https://github.com/isaacs/npm
mv npm npm-1.1.49
cd npm-1.1.49
git checkout v1.1.49
./configure
make
sudo make install

Version check

At this point, we should see the following:

>node -v
v0.8.7
>npm -v
1.1.49

socket.io chat example

Let’s download and run the socket.io chat example:

cd ~/node-socket.io
git clone https://github.com/LearnBoost/socket.io.git
cd socket.io
sudo npm cache clean
npm install .
cd examples/chat
npm install .

Be sure to run both npm installs! It will install all dependencies for the chat application. We were failing to run the highlighted step.

Start the application

cd ~/node-socket.io/socket.io/examples/chat
node app.js

You should see output similar to:

   info  - socket.io started
   app listening on http://0.0.0.0:3000

Now you can visit http://localhost:3000 in your browser and play with the chat application.

Let me know if you have any problems.