A work in progress script to provision a raspberry pi with raspbian

provision-pi.sh

#!/bin/bash

export HOSTNAME='***' 
TOOLS="tmux"
COUNTRY="**"
SSID="***" 

function change_hostname {
	sudo sh -c "echo $HOSTNAME > /etc/hostname"
	sudo sed -i "s/raspberrypi/$HOSTNAME/g" /etc/hosts
	sudo sh -c "echo 127.0.0.1 $HOSTNAME >> /etc/hosts"
}

function enable_sshd {
	sudo systemctl enable ssh.service
	sudo systemctl start ssh.service
}

function update_packages {
	sudo apt-get update
}

function install_tools {
	sudo apt-get install -y $TOOLS
}

function update_locales {
	export LANGUAGE=en_US.UTF-8
	export LANG=en_US.UTF-8
	export LC_ALL=en_US.UTF-8
	sudo locale-gen en_US.UTF-8
	sudo update-locale LANG=en_US.UTF-8
}

function configure_wlan0 {
	FILE="/etc/wpa_supplicant/wpa_supplicant.conf"
	sudo grep -q "country=$COUNTRY" "$FILE" || echo "country=$COUNTRY" | sudo tee -a "$FILE"
	if ! sudo grep -q "$SSID" "$FILE"; then
		echo "Enter password for $SSID:"
		NETINFO=$(wpa_passphrase "$SSID")
		PARSEDNETINFO=$(echo "$NETINFO" |  sed '/#/ d' )
		sudo grep -q "$PARSEDNETINFO" "$FILE" || echo "$PARSEDNETINFO" | sudo tee -a "$FILE"
	else
		echo "$SSID network configuration detected in $FILE, skipping..."
	fi
	sudo wpa_cli -i wlan0 reconfigure
	sudo dhcpcd wlan0
}

# not necessary in most recent raspbian versions
# see https://raspberrypi.stackexchange.com/a/37921
function configure_dhcp {
	DHCP_CONFIG=$(cat <<_EOF_
auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
_EOF_)
	FILE="/etc/network/interfaces"
	sudo grep -q "$DHCP_CONFIG" "$FILE" || echo "$DHCP_CONFIG" | sudo tee -a "$FILE"
	sudo dhcpcd -k wlan0
	sudo dhcpcd wlan0
}

function test_wlan0 {
	ifconfig wlan0
	route -n
	ip rule show
	ip route show table local
}

function change_password {
	passwd pi
}

###

change_hostname
enable_sshd
update_locales
update_packages
install_tools
configure_wlan0
test_wlan0
change_password