#!/bin/bash

os_conf_dir=/aliyun_custom_image
os_conf_file=${os_conf_dir}/os.conf

load_os_conf() {
    if [[ -f $os_conf_file ]]; then
        . $os_conf_file
        echo $password
        return 0
    else
        return 1
    fi
}

cleanup() {
    # ensure $os_conf_file is deleted, to avoid repeating config system
    rm $os_conf_file >& /dev/null
    # ensure $os_conf_dir is exitst
    mkdir -p $os_conf_dir
}

config_password() {
    if [[ -n $password ]]; then
        password=$(echo $password | base64 -d)
        if [[ $? == 0 && -n $password ]]; then
            echo "root:$password"
            echo "root:$password" | chpasswd
        fi
    fi
}
config_hostname() {
    if [[ -n $hostname ]]; then
        echo "$hostname" > /etc/hostname
        hostnamectl set-hostname $hostname
    fi
}
config_network() {
    if [[ -n $eth0_ip_addr ]]; then
        config_interface
        systemctl restart systemd-networkd
    fi
}
config_interface() {
    mask2cdr $eth0_netmask
    cat << EOF > /etc/systemd/network/default.network
# Generated by Aliyun Custom OS helper
# DO NOT EDIT THIS FILE! IT WILL BE OVERWRITTEN

[Match]
Name=$(ip link | awk -F: '$0 !~ "lo|vir|wl|^[^0-9]"{print $2a;getline}' | sed -e 's/^[[:space:]]*//')

[Network]
Address=$eth0_ip_addr/$netmask
Gateway=$eth0_gateway

[Link]
MACAddress=$eth0_mac_address

[Address]
Address=$eth0_ip_addr/$netmask
EOF
    echo "nameserver 1.1.1.1" > /etc/resolv.conf
    for ns in $dns_nameserver
    do
        echo "nameserver $ns" >> /etc/resolv.conf
    done
}

mask2cdr() {
    # Assumes there's no "255." after a non-255 byte in the mask
    local x=${1##*255.}
    set -- 0^^^128^192^224^240^248^252^254^ $(( (${#1} - ${#x})*2 )) ${x%%.*}
    x=${1%%$3*}
    netmask=$(( $2 + (${#x}/4) ))
}

if load_os_conf ; then
    config_password
    config_hostname
    config_network
    cleanup
else
    echo "not load $os_conf_file"
fi