阿里云ddns一键脚本完全版本

之前找了个国内将国内动态IP定时同步到阿里云DDNS的脚本，但是在实际使用过程中不是很好用。

这次加了个判断，由于我的检测频率过高，本地缓存一次IP地址进行判断，若是IP已经变化，则请求域名解析接口，若没有，则结束脚本。

启发来自于Cloudflare的ddns脚本，我发现这样做更好一些，起码不会频繁请求接口。

脚本：

#!/bin/bash
set -e

#================================================================================================================#
# 功能：用于更新阿里云域名IP，实现DDNS功能
#
# 在 http://www.gebi1.com/forum.php?mod=viewthread&tid=287344&page=1&_dsign=8f94f74c 提供的脚本文件基础上修改的。
# ghui, modified 12/2/2019
# 在 N1 debian Buster with Armbian Linux 5.3.0-aml-g12 手动执行/定时任务(crontab)执行测试通过
# 融合了Cloudflare DDNS脚本中IP未改变则不提交更新的功能
#================================================================================================================#
#
# 使用方法：
#
# 方法1. 外部参数
# 修改源码，将对应参数 修改为$1,$2,$3,$4,$5,$6 
# aliddns.sh <aliddns_ak> <aliddns_sk> <aliddns_subdomain> <aliddns_domain> <aliddns_iptype> <aliddns_ttl>
# 示例（A 代表 IPv4，AAAA 代表 IPv6）： 
# 执行：aliddns.sh "xxxx" "xxx" "test" "mydomain.site" "A" 600
# 执行：aliddns.sh "xxxx" "xxx" "test" "mydomain.site" "AAAA" 600
#
# 方法2. 内部参数
# 修改源码，将$1,$2,$3,$4,$5,$6 替换为对应参数
# 
# 示例： 
# aliddns_ak="xxxx"
# aliddns_sk="xxx"
# aliddns_subdomain="test"
# aliddns_domain="mydomain.site"
# aliddns_iptype="A"
# aliddns_ttl=600 
# 执行：aliddns.sh
#
#================================================================================================================#

#--------------------------------------------------------------
# 参数
#
# (*)阿里云 AccessKeyId 
aliddns_ak="你的AccessKeyId"
# (*)阿里云 AccessKeySecret 
aliddns_sk="你的AccessKeySecret"

# (*)域名：test.mydomain.com 
aliddns_subdomain="test" #'只需填写前缀二级'
aliddns_domain="ip.cn" #'mydomain.com'

# (*)ip地址类型：'A' 或 'AAAA'，代表ipv4 和 ipv6
aliddns_iptype="A" # 'A' 或 'AAAA'，代表ipv4 和 ipv6

# TTL 默认10分钟 = 600秒 
aliddns_ttl=600 #"600"

# 是否强制更新，即使IP未改变
FORCE=false

# 存储上次IP的文件路径
WAN_IP_FILE="$HOME/.aliddns-wan_ip_${aliddns_subdomain}_${aliddns_domain}_${aliddns_iptype}.txt"

#--------------------------------------------------------------

machine_ip=""
ddns_ip=""
aliddns_record_id=""

if [ "$aliddns_subdomain" = "@" ]; then
  aliddns_name=$aliddns_domain
else
  aliddns_name="$aliddns_subdomain.$aliddns_domain"
fi

now=$(date)
echo "**************************************************"
echo "$now"
echo "$aliddns_name"
# 这里接口用的ipw.cn，ipv6的对应地址为https://6.ipw.cn
function getMachine_IPv4() { 
    echo $(/usr/bin/wget -qO- -t1 -T2 https://4.ipw.cn)
}

function getMachine_IPv6() { 
    ipv6=$(ip addr | grep "inet6.*global" | grep -v "deprecated" | awk '{print $2}' | awk -F"/" '{print $1}' | sed -n '1,1p')
    echo $ipv6
}

function getDDNS_IP() { 
    current_ip=$(nslookup -query=$aliddns_iptype $aliddns_name | grep "Address" | grep -v "#53" | awk '{print $2}')
    echo $current_ip
}

function urlencode() { 
    # urlencode <string>
    out=""
    while read -n1 c; do
        case $c in
            [a-zA-Z0-9._-]) out="$out$c" ;;
            *) out="$out$(printf '%%%02X' "'$c")" ;;
        esac
    done
    echo -n $out
}

function enc() { 
    echo -n "$1" | urlencode
}

function send_request() { 
    local args="AccessKeyId=$aliddns_ak&Action=$1&Format=json&$2&Version=2015-01-09"
    local hash=$(echo -n "GET&%2F&$(enc "$args")" | openssl dgst -sha1 -hmac "$aliddns_sk&" -binary | openssl base64)
    curl -s "http://alidns.aliyuncs.com/?$args&Signature=$(enc "$hash")"
}

function get_recordid() { 
    grep -Eo '"RecordId":"[0-9]+"' | cut -d':' -f2 | tr -d '"'
}

function query_recordid() { 
    send_request "DescribeSubDomainRecords" "SignatureMethod=HMAC-SHA1&SignatureNonce=$timestamp&SignatureVersion=1.0&SubDomain=$aliddns_name&Timestamp=$timestamp&Type=$aliddns_iptype"
}

function update_record() { 
    send_request "UpdateDomainRecord" "RR=$aliddns_subdomain&RecordId=$1&SignatureMethod=HMAC-SHA1&SignatureNonce=$timestamp&SignatureVersion=1.0&TTL=$aliddns_ttl&Timestamp=$timestamp&Type=$aliddns_iptype&Value=$(enc $machine_ip)"
}

function add_record() { 
    send_request "AddDomainRecord&DomainName=$aliddns_domain" "RR=$aliddns_subdomain&SignatureMethod=HMAC-SHA1&SignatureNonce=$timestamp&SignatureVersion=1.0&TTL=$aliddns_ttl&Timestamp=$timestamp&Type=$aliddns_iptype&Value=$(enc $machine_ip)"
}

# 获取当前机器IP
if [ "$aliddns_iptype" = 'A' ]; then
    echo "ddns is IPv4."
    machine_ip=$(getMachine_IPv4)
    echo "machine_ip = $machine_ip"
    aliddns_record_id=$aliddnsipv4_record_id
else
    echo "ddns is IPv6."
    machine_ip=$(getMachine_IPv6)
    echo "machine_ip = $machine_ip"
    aliddns_record_id=$aliddnsipv6_record_id
fi

# 检查是否获取到IP
if [ -z "$machine_ip" ]; then
    echo "machine_ip is empty!"
    exit 0
fi

# 获取DDNS当前解析的IP
ddns_ip=$(getDDNS_IP)
echo "ddns_ip = $ddns_ip"

# 获取上次记录的IP
if [ -f $WAN_IP_FILE ]; then
    OLD_WAN_IP=$(cat $WAN_IP_FILE)
else
    OLD_WAN_IP=""
fi

# 如果IP未改变且不强制更新，则退出
if [ "$machine_ip" = "$OLD_WAN_IP" ] && [ "$FORCE" = false ]; then
    echo "IP Unchanged, to update anyway use flag -f true"
    exit 0
fi

# 如果DNS记录IP与当前IP相同，则退出
if [ "$machine_ip" = "$ddns_ip" ]; then
    echo "DNS record already up to date"
    exit 1
fi

echo "start update..."

timestamp=$(date -u "+%Y-%m-%dT%H%%3A%M%%3A%SZ")

if [ -z "$aliddns_record_id" ]; then
    aliddns_record_id=$(query_recordid | get_recordid)
    echo "---------------- $aliddns_record_id"
    
    if [ "$aliddns_iptype" = 'A' ]; then
        aliddnsipv4_record_id=$aliddns_record_id
    else
        aliddnsipv6_record_id=$aliddns_record_id
    fi
fi

# Add support */%2A and @/%40 record
if [ -z "$aliddns_record_id" ]; then
    echo "add record starting"
    aliddns_record_id=$(add_record | get_recordid)

    if [ -z "$aliddns_record_id" ]; then
        echo "aliddns_record_id is empty."
    else
        if [ "$aliddns_iptype" = 'A' ]; then
            aliddnsipv4_record_id=$aliddns_record_id
        else
            aliddnsipv6_record_id=$aliddns_record_id
        fi
        echo "added record $aliddns_record_id"
        # 保存当前IP到文件
        echo $machine_ip > $WAN_IP_FILE
    fi
else
    echo "update record starting"
    update_record $aliddns_record_id
    echo "updated record $aliddns_record_id"
    # 保存当前IP到文件
    echo $machine_ip > $WAN_IP_FILE
fi