cluster-init.sh

#!/bin/bash
# vim: set noet sw=4 sts=4 ts=4:


RELEASE='Fedora-Atomic-26-20170821.0'
CHKSUM='Fedora-CloudImages-26-20170821.0-x86_64-CHECKSUM'
IMAGE="$RELEASE.x86_64.qcow2"
SUBNET="88"
printf -v MAC_PREFIX '52:54:00:%02x:00' "$SUBNET"
DOMAIN="cluster"
HOST_PASS='atomic'
HOST_VOL=10G
HOST_MEM=1024
HOST_CPU=1


log_info() {
	if [[ $TERM =~ color ]]; then
		>&2 printf '\e[1;32m==>\e[0m \e[1m%s\e[0m\n' "$*"
	else
		>&2 printf '==> %s\n' "$*"
	fi
}


__setup_download() {
	log_info 'Importing Fedora GPG keyring'
	curl -L 'https://getfedora.org/static/fedora.gpg' | gpg --import
	log_info 'Downloading GPG signed image checksums'
	curl -LO "https://download.fedoraproject.org/pub/alt/atomic/stable/$RELEASE/CloudImages/x86_64/images/$CHKSUM"
	log_info 'Verifying checksum signature'
	gpg --verify-files "$CHKSUM"
	log_info 'Verifying image checksums (checking for previous download)'
	sha256sum -c --ignore-missing "$CHKSUM" && {
		log_info 'Image already downloaded'
		return
	}
	log_info 'Downloading Fedora Atomic host cloud image'
	curl -LO "https://download.fedoraproject.org/pub/alt/atomic/stable/$RELEASE/CloudImages/x86_64/images/$IMAGE"
	log_info 'Verifying image checksum'
	sha256sum -c --ignore-missing "$CHKSUM"
}


__setup_sshkeys() {
	log_info 'Setting up SSH keypair...'
	ssh-keygen -t rsa -b 4096 -C 'cluster-key' -N '' -q -f id_rsa
	log_info 'SSH keypair created. Public key:'
	pubkey="$(<id_rsa.pub)"
	echo "$pubkey"
}


__setup_network() {
	log_info "Setting up cluster network (192.168.$SUBNET.0/24)"
	sudo virsh net-uuid cluster-network &>/dev/null && {
		log_info 'Network already created. Skipping...'
		return
	}
	cat > cluster-network.xml <<-EOF
	<network ipv6="yes">
		<name>cluster-network</name>
		<domain name="$DOMAIN" localOnly="no" />
		<mac address="$MAC_PREFIX:fe" />
		<bridge name="cluster0" stp="on" delay="0" />
		<forward mode="nat" />
		<ip address="192.168.$SUBNET.254" netmask="255.255.255.0" localPtr="yes">
			<dhcp>
				<range start="192.168.$SUBNET.11" end="192.168.$SUBNET.254" />
				<host mac="$MAC_PREFIX:01" name="node01.$DOMAIN" ip="192.168.$SUBNET.1" />
				<host mac="$MAC_PREFIX:02" name="node02.$DOMAIN" ip="192.168.$SUBNET.2" />
				<host mac="$MAC_PREFIX:03" name="node03.$DOMAIN" ip="192.168.$SUBNET.3" />
				<host mac="$MAC_PREFIX:04" name="node04.$DOMAIN" ip="192.168.$SUBNET.4" />
				<host mac="$MAC_PREFIX:05" name="node05.$DOMAIN" ip="192.168.$SUBNET.5" />
				<host mac="$MAC_PREFIX:06" name="node06.$DOMAIN" ip="192.168.$SUBNET.6" />
				<host mac="$MAC_PREFIX:07" name="node07.$DOMAIN" ip="192.168.$SUBNET.7" />
				<host mac="$MAC_PREFIX:08" name="node08.$DOMAIN" ip="192.168.$SUBNET.8" />
				<host mac="$MAC_PREFIX:09" name="node09.$DOMAIN" ip="192.168.$SUBNET.9" />
				<host mac="$MAC_PREFIX:10" name="node10.$DOMAIN" ip="192.168.$SUBNET.10" />
			</dhcp>
		</ip>
	</network>
	EOF
	sudo virsh net-create --file cluster-network.xml
}


__setup_vms() {
	log_info 'Setting up virtual machines'
	read -e -p 'Enter the number of Atomic hosts: ' -i 1 num_hosts

	local host_ips=()

	for (( host=1; host<=num_hosts; host++ )); do
		# zero-pad the host number up to 2 digits (e.g. 01...99)
		local _host
		printf -v _host '%02d' "$host"

		mkdir -pv "$_host"
		pushd "$_host"

		# Step 1: create the cloud-init meta-data file
		cat > meta-data <<-EOF
		instance-id: atomic-host$_host
		local-hostname: node$_host.$DOMAIN
		EOF

		# Step 2: create the cloud-init user-data file
		cat > user-data <<-EOF
		#cloud-config
		package_upgrade: true
		password: $HOST_PASS
		ssh_pwauth: true
		chpasswd: { expire: false }
		
		ssh_authorized_keys:
		  - $pubkey
		EOF

		# Step 3: create the cloud-init ISO image for each machine
		genisoimage -output init.iso -volid cidata -joliet -rock user-data meta-data

		# Step 4: create a thinly provisioned snapshot for each machine
		qemu-img create -b "../$IMAGE" -f qcow2 "$_host.qcow2"
		qemu-img resize "$_host.qcow2" "$HOST_VOL"

		# Step 5: install each virtual machine
		local _name
		printf -v _name 'f26-atomic%02d' "$host"
		local _mac
		# Convert host number to hex MAC address
		printf -v _mac "$MAC_PREFIX:%02x" "$host"
		sudo virt-install \
			-n "$_name" \
			--os-type=Linux \
			--os-variant=fedora25 \
			--ram="$HOST_MEM" \
			--vcpus="$HOST_CPU" \
			--disk path="$_host.qcow2",bus=virtio \
			--cdrom "$(pwd)"/init.iso \
			--network network=cluster-network,model=virtio,mac="$_mac" \
			--graphics none \
			--noautoconsole
		host_ips+=("192.168.$SUBNET.$host")
		popd
	done

	log_info "Done setting up $num_hosts virtual machine(s). Ready to login:"
	for host_ip in ${host_ips[@]}; do
		echo -e "\tssh -i id_rsa fedora@$host_ip"
	done
}


__setup_download
__setup_sshkeys
__setup_network
__setup_vms