Initial setup to get chef-client running on raspbian

prepare_node.sh

#!/bin/bash

: <<'END' # Block comment
Use this script to prepare a clean raspbian image to run chef-client
Do not forget to add an empty file named "ssh" on the "boot" partition of your raspbian image to enable the ssh daemon.
If you did not run ssh-keygen before on your host machine, please do so before running this script.

This script sets up the debian testing packages as ruby 2.3 is currently not available in jessy. It also adds a pinning entry so packages available in jessy are preferred.
Afterwards it installs the chef gem and we are ready to bootstrap our new node :)
END


if [ $# -ne 1 ]; then
	echo "usage: $0 ip_address"
fi

sshpass -V > /dev/null
if [ $? -ne 0 ]; then
	sudo apt install sshpass
fi

ip=$1
username="pi"
pw="raspberry"

#delete old keys (from former trials :) ) from your known_hosts file
ssh-keygen -f "~/.ssh/known_hosts" -R $ip

#add our key to the raspberry without it requesting a password
sshpass -p $pw ssh-copy-id -o "StrictHostKeyChecking no" $username@$ip

# This is where the fun begins
ssh $username@$ip <<ENDSSH
echo "$pw" | sudo -S ls #trigger sudo password entry
sudo -i
echo "deb http://mirrordirector.raspbian.org/raspbian/ testing main contrib non-free rpi" | tee -a /etc/apt/sources.list
echo -e "Package: *\nPin: release a=testing\nPin-Priority: 400\n" | tee -a /etc/apt/preferences.d/testing
apt-get update

echo "Updating time"
apt-get -y install ntp ntpdate
service ntp stop
ntpdate -s time.nist.gov
service ntp start

echo "Installing ruby"
apt-get install -t testing -y ruby-dev

echo "Installing chef"
gem install chef

#echo "192.168.0.8 chef-server.test" | tee -a /etc/hosts
ENDSSH