shark

#!/usr/bin/env bash

set -o errexit -o errtrace -o nounset -o pipefail

# Global variable names begin with double underscore.
__project_path="$PWD"
__vm_config_file_name='Sharkfile'
__vm_config_file_path="${__project_path}/${__vm_config_file_name}"

error_message_and_exit() {
    set_text_color 'red'
    echo "Error: ${1}" >&2
    set_text_color 'restore'

    exit 1
}

info_message() {
    set_text_color 'blue'
    echo "Info: ${1}"
    set_text_color 'restore'
}

set_text_color() {
    if [[ 'red' == ${1} ]]; then
        echo -e "\\x1b[31m" 1>&2
    elif [[ 'blue' == ${1} ]]; then
        echo -e "\\x1b[34m" 1>&2
    elif [[ 'restore' == ${1} ]]; then
        echo -e "\\x1b[0m" 1>&2
    else
        echo "Text color '${1}' is not supported." >&2

        exit 1
    fi
}

__action=''
[[ ! -z ${1:-} ]] && __action="${1}"
[[ '' = ${__action} ]] && error_message_and_exit "Action must be defined (first argument). Try using 'init' action which will create config files for VM in the current directory."

init() {
    [[ -f ${__vm_config_file_path} ]] \
        && error_message_and_exit "File '${__vm_config_file_path}' already exists."

    cat <<- 'EOF' > "${__vm_config_file_path}"
		#!/usr/bin/env bash

		# These variables MUST be defined:
		__original_cloud_image_path=''
		# VM name should be unique across all VMs on the current host.
		__vm_name=''

		# Leave default values if you wish:
		__vm_disk_image_directory="${HOME}/.cache/${__vm_config_file_name}/${__vm_name}"
		__vm_disk_image_file_path="${__vm_disk_image_directory}/${__vm_name}.qcow2"
		__vm_memory=1024
		__vm_vcpus=1
		__vm_disk="'${__vm_disk_image_file_path}',size=20"
		__vm_cloud_init='user-data=user-data'
		__virt_install_command="virt-install --import --osinfo detect=on,require=off --name '${__vm_name}' --memory '${__vm_memory}' --vcpus '${__vm_vcpus}' --disk '${__vm_disk}' --cloud-init '${__vm_cloud_init}'"

		# Before creating VM, for the first time, with `up` action to see it in Virtual Machine Manager in
		# `File > Add Connection... > Hypervisor` select `QEMU/KVM user session` which is on URI:
		# qemu:///session
	EOF

    [[ -f './user-data' ]] \
        && error_message_and_exit "File '${__project_path}/user-data' already exists."

    cat <<- 'EOF' > './user-data'
		#cloud-config

		system_info:
		    default_user:
		        name: "admin"
		        plain_text_passwd: "admin"
		        lock_passwd: false
		        groups: ["sudo"]
	EOF

    info_message "Initialization is done. Edit '${__vm_config_file_path}' before starting VM with 'up' action."
}

load_and_verify_vm_config() {
    [[ ! -f ${__vm_config_file_path} ]] \
        && error_message_and_exit "File '${__vm_config_file_path}' is not found. Use 'init' action to create one."
    source "${__vm_config_file_path}"

    [[ ! -f ${__original_cloud_image_path} ]] \
        && error_message_and_exit "File '${__original_cloud_image_path}' is not found, it is defined as original cloud image in '${__vm_config_file_path}'."

    [[ -z ${__vm_name} ]] \
        && error_message_and_exit "Name for VM is not defined in '${__vm_config_file_path}'."

    info_message "VM configuration is valid."
}

up() {
    load_and_verify_vm_config

    mkdir -p "${__vm_disk_image_directory}"

    if [[ -f ${__vm_disk_image_file_path} ]]; then
        info_message "VM disk image already exists '${__vm_disk_image_file_path}', we are not going to copy distribution cloud image."
    else
        info_message "Copy distribution cloud image '${__original_cloud_image_path}' to be used as disk image for VM '${__vm_disk_image_file_path}'."
        cp "${__original_cloud_image_path}" "${__vm_disk_image_file_path}"
    fi

    eval "${__virt_install_command}"
}

main() {
    if [[ 'init' == ${__action} ]]; then
        init
    elif [[ 'up' == ${__action} ]]; then
        up
    else
        error_message_and_exit "Action '${__action}' is not supported."
    fi
}

main "$@"
exit