If you are running CoreOS in a virtual environment, you can automatically configure CoreOS by cloud-config. This can be achieved by creating a configdrive ISO and mount it at boottime. CoreOS will scan the CD-ROM and will execute the cloud-config.

Script to generate the ISO based on the cloud-config

This script will generate an configdrive ISO based on the given cloud-config.

Supports the following OS

1. Mac OS
2. Linux

Usage

$ createIso.sh --cloud-config cloud-config.yml --name application

createiso.sh

#!/usr/bin/env bash
PATH_TEMP=/tmp/new-drive
PATH_ISO_MAC=which hdiutil
PATH_ISO_LINUX=which mkisofs
ISO_COMMAND=“none”
if [[  -f “${PATH_ISO_MAC}” ]]; then
echo “MacOS Detected, using hdiutil tool”
ISO_COMMAND=“mac”
fi
if [[  -f “${PATH_ISO_LINUX}” ]]; then
echo “Linux Detected, using mkisofs tool”
ISO_COMMAND=“linux”
fi
if [[ “${ISO_COMMAND}” == “none” ]]; then
echo “Cannot find hdiutil for mac or mkisofs for linux.”
echo “Please install required tools”
exit;
fi
while [[ $# > 1 ]]
do
key="$1"
case $key in
–name)
NAME="$2"
shift # past argument
;;
–cloud-config)
CLOUD_CONFIG="$2"
shift # past argument
;;
*)
# unknown option
;;
esac
shift # past argument or value
done
if [ -z “${CLOUD_CONFIG}” ]; then
echo “usage: createIso.sh –cloud-config cloud-config.yml –name application”;
exit
fi
if [ -z “${NAME}” ]; then
echo “usage: createIso.sh –cloud-config cloud-config.yml –name application”;
exit;
fi
if [[ ! -f “${CLOUD_CONFIG}” ]]; then
echo “Cloud config file not found (${CLOUD_CONFIG})”
exit;
fi
echo “Creating config drive with cloud-config ‘${CLOUD_CONFIG}’”
mkdir -p ${PATH_TEMP}/openstack/latest
cp ${CLOUD_CONFIG} ${PATH_TEMP}/openstack/latest/user_data
if [[ “${ISO_COMMAND}” == “linux” ]]; then
mkisofs -R -V config-2 -o configdrive-${NAME}.iso ${PATH_TEMP}
fi
if [[ “${ISO_COMMAND}” == “mac” ]]; then
hdiutil makehybrid -iso -joliet -default-volume-name config-2 -o configdrive-${NAME}.iso ${PATH_TEMP}
fi
#Cleanup
rm -r ${PATH_TEMP}