RPi.md

Node on the RPi

If you already have your Raspberry Pi configured and have installed Node.js and node-gyp you can skip these instructions.

Configure the RPi

There are certain tasks that must be done immediately when bringing up new RPi system.

First, we connect to the platform via ssh -- the username (pi) and passphrase(raspberry) are the defaults (we'll fix that momentarily):

    % ssh [email protected]
    [email protected]'s password: raspberry
    ...
    pi@raspberrypi ~ $

Localize the Timezone

Now configure the timezone:

    pi@raspberrypi ~ $ sudo raspi-config

Select option 4 ("Internationalization Options") and then I2 ("Change Timezone") to set your timezone.

The next thing to do is make sure the platform is current with respect to its packages:

    pi@raspberrypi ~ $ sudo apt-get update
    ...
    pi@raspberrypi ~ $ sudo apt-get upgrade -y
    ...
    pi@raspberrypi ~ $ sudo reboot

These commands may take a while. Please be patient.

Remote Access only via ssh

Second, let's fix the default password. Generate an ssh keypair on your desktop:

    % ssh-keygen -b 4096 -t rsa 
    ...
    Enter file in which to save the key (/Users/apple/.ssh/id_rsa): /Users/apple/.ssh/id_homespun
    Enter passphrase (empty for no passphrase):
    Enter same passphrase again:
    Your identification has been saved in /Users/apple/.ssh/id_homespun.
    Your public key has been saved in /Users/apple/.ssh/id_homespun.pub.
    ...

Create the .ssh directory on the platform:

    pi@raspberrypi ~ $ mkdir -p ~/.ssh
    pi@raspberrypi ~ $ chmod 700 ~/.ssh

Copy the public key from your desktop to the platform:

    % ssh [email protected] 'cat >> .ssh/authorized_keys' < ~/.ssh/id_homespun.pub
    [email protected]'s password: raspberry

Configure the platform so that only ssh with a private key is allowed:

    pi@raspberrypi ~ $ sudo vi /etc/ssh/sshd_config

and change these two lines:

    # Change to no to disable tunnelled clear text passwords
    #PasswordAuthentication yes

to this:

    # do not allow plaintext passwords
    PasswordAuthentication no

Finally, run this:

    pi@raspberrypi ~ $ sudo /etc/init.d/ssh restart

Henceforth, you will connect to the platform like this:

    % ssh -i ~/.ssh/id_homespun.pub [email protected]

Disable some Bonjour advertisements

By default, the RPi advertises some unnecessary services.

First, run this to disable the _udisks-ssh._tcp service:

    pi@raspberrypi ~ $ cd /etc/avahi
    pi@raspberrypi ~ $ sudo mkdir disabled
    pi@raspberrypi ~ $ sudo mv services/udisks.service disabled

Next, disable the _workstation._tcp service:

    pi@raspberrypi ~ $ sudo vi avahi-daemon.conf

and look for the line that says:

    #publish-workstation=yes

and change it to:

    publish-workstation=no

Finally, run this:

    pi@raspberrypi ~ $ sudo /etc/init.d/avahi restart

Get Node.js

The first thing you want to do is see if node is already there, and if so, what version you have. The commands that follow should work on any Linux system; however, the examples will all be based on using an RPi:

    pi@raspberrypi ~ $ node --version
    -bash: node: command not found

In this case, the answer is no; otherwise we'd see something like this:

    pi@raspberrypi ~ $ node --version
    v5.1.1

In this case, the version number is v5.1.1. If the version number is less than v0.10.40, then you're going to need to install a newer version of Node.js.

Personally, I prefer to build Node.js from scratch, but that takes a while and is probably too old school for most folks. So, here's the alternative:

    pi@raspberrypi ~ $ curl -sL https://deb.nodesource.com/setup_0.10 | sudo bash -
    ...
    pi@raspberrypi ~ $ sudo apt-get install -y nodejs build-essential
    ...

However, if you really do want to install from scratch

    pi@raspberrypi ~ $ git clone https://github.com/nodejs/node.git
    ...
    pi@raspberrypi ~ $ cd node
    pi@raspberrypi ~/node $ git checkout v5.1.1 -b v5.1.1
    pi@raspberrypi ~/node $ ./configure --without-snapshot

    pi@raspberrypi ~/node $ make
    ...
    pi@raspberrypi ~/node $ sudo make install
    ...

By the way, this may take a quite a while.

Install node-gyp

If a Node.js module needs to make use of a native API (perhaps to access a kernel facility), then it probably uses node-gyp for this purpose. Let's install that as well:

    pi@raspberrypi ~ $ git clone https://github.com/TooTallNate/node-gyp.git
    ...
    pi@raspberrypi ~ $ cd node-gyp/
    pi@raspberrypi ~/node-gyp $ sudo npm install -g node-gyp
    ...

That is all, for now!