利用 cloudflare dns 做 ddns

cfddns_self_ip.sh

#!/bin/bash
## 利用 cloudflare dns 做 ddns
## 不再用 tp 路由器后，就要在手机或笔电服务器来检测自身公网 ip 了
## curl ifconfig 可以用来获取公网 ip
##
## 使用：
##   可以把本文件保存为 /home/您的用户/cfddns_self_ip.sh
##   然后执行 crontab -e 
##   在出来的文件编辑里添加一行 
##   */5 * * * * bash /home/您的用户/cfddns_self_ip.sh
##   来每隔 5 分钟自动运行一次更新 ddns
##
##   或者也可以把文件加上可执行权限放到 /etc/network/if-up.d/
##   来让网络变动时自动执行（不过，不适合放在路由器后的情况，因为这不会感知路由器外网 ip 变化）


# can be A or AAAA
do_record=A
# the interface to get ipv6 address
iface=eth0
# the static suffix we should add to
v6_suf=53

mail="填入您在 cf 注册的邮箱"
authkey="填入您在 cf 申请的 api key"
record="填入您要修改的域名"

cachef=~/.cfddns-$record

cfupdate () {
    _type=$1
    _addr=$2
    echo "Update $_type record for $record to $_addr"

    ret=$(curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$zoneid/dns_records/$recordid" \
        -H "X-Auth-Email: $mail" \
        -H "X-Auth-Key: $authkey" \
        -H "Content-Type: application/json" \
        --data '{"type":"'$_type'","name":"'$record'","content":"'$_addr'"}')
    
    if [[ -z $(echo $ret|grep -oP "success\":[^\"]+"|grep true) ]]; then
        echo $ret
    else
        echo "OK."
    fi
}

if [[ ! -e $cachef ]]; then
    touch $cachef
fi

if [[  $(cat $cachef|grep "id,"|wc -l) -ne 2 ]]; then
    domain=$(echo $record |grep -oP "[^.]+\.[^.]+$")
    ret=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$domain" \
        -H "X-Auth-Email: $mail" \
        -H "X-Auth-Key: $authkey" \
        -H "Content-Type: application/json")
    zoneid=$(echo $ret|grep -oP "\"id\":\"[a-f\d]{32}"|grep -oP "[a-f\d]{32}"|head -n1)
    ret=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zoneid/dns_records?name=$record&type=$do_record" \
        -H "X-Auth-Email: $mail" \
        -H "X-Auth-Key: $authkey" \
        -H "Content-Type: application/json")
    recordid=$(echo $ret|grep -oP "\"id\":\"[a-f\d]{32}"|grep -oP "[a-f\d]{32}"|head -n1)
    echo "recordid,$do_record,$recordid" >> $cachef
    echo "zoneid,$zoneid" >> $cachef
else
    recordid=$(cat $cachef|grep "recordid,$do_record"|grep -oP "[a-f\d]{32}")
    zoneid=$(cat $cachef|grep zoneid|grep -oP "[a-f\d]{32}")
fi

if [[ -z $recordid || -z $zoneid ]]; then
    echo "Unable to get recordid or zoneid"
    rm -f $cachef
    exit 0
fi

if [[ $do_record = "A" ]]; then 
    #addr_v4=$(curl ipip.tk/ip -4s)
    #addr_v4='131.213.206.199'
    ## 利用 nslookup 来解析域名的 ip 记录
    ## 不再用 tp 路由器后，就要在手机或笔电服务器来检测自身公网 ip 了
    ## ifconfig.me 有点慢，改用 ip.sb 好了；debian 默认安装了 wget 而没有 curl，所以用 wget -q -O- ip.sb 代替了
    #addr_v4=$(curl ifconfig.me)
    addr_v4=$(wget -q -O- ip.sb)
    last_addr_v4=$( nslookup "$record" | grep -oP '\d+\.\d+\.\d+\.\d+' | sed 1,2d | head -1 )
    ## 域名 ip 记录没变化则退出
    #if [[ -z $(cat $cachef|grep $addr_v4) ]]; then
    ## [ xxx -a ooo ] 表示同时满足 xxx 并且 bbb
    if [ -n "$last_addr_v4" -a "$last_addr_v4" != "$addr_v4" -a "$addr_v4" != "0.0.0.0" ]; then
            sed -i "/v4,/d" $cachef
            echo "v4,$addr_v4" >> $cachef
            cfupdate "A" $addr_v4
            echo "Update A record for $record from $last_addr_v4 to $addr_v4"
    fi
else
    # check if we have ipv6 address

    if [[ -z $(ifconfig $iface|grep inet6|grep -P "2[\da-f:]{4,}") ]]; then exit; fi

    addr_v6_prefix=$(curl ip.sb -6s|grep -oP "[\da-f]+:[\da-f]+:[\da-f]+:[\da-f]+"|cut -f1|head -n1 )

    # check if we really can use ipv6
    if [[ -z $addr_v6_prefix ]]; then exit; fi

    addr_v6="$addr_v6_prefix::$v6_suf"

    if [[ -z $(ifconfig $iface|grep $addr_v6) ]]; then
        echo "Adding $addr_v6 to $iface"
        ip -6 addr add $addr_v6/64 dev $iface
    fi


    if [[ -z $(cat $cachef|grep $addr_v6) ]]; then
        sed -i "/v6,/d" $cachef
        echo "v6,$addr_v6" >> $cachef
        cfupdate "AAAA" $addr_v6
    fi
fi