将 DNSPod 上指定子域名指向当前本机 IP 的脚本

update_self.sh

#!/bin/bash

# 将 DNSPOD 上指定子域名指向当前本机 IP 的脚本
#
# 依赖：
# urlencode: http://www.shelldorado.com/scripts/cmds/urlencode
# jsawk: https://github.com/micha/jsawk

# 配置信息
EMAIL=""
PASSWORD=""
DOMAIN=""
SUBDOMAIN=""
USERAGENT="update self/0.3.2 ([email protected])"
# 检查间隔
INTERVAL=30
# 记录文件
LOGFILE=""

# 进行 URL 编码
EMAIL="$(echo "$EMAIL" | urlencode)"
PASSWORD="$(echo "$PASSWORD" | urlencode)"

# 去除字符串首位的引号
remove_quote()
{
    local str
    read str
    echo ${str:1:${#str}-2}
}

# 发起 API 请求
# 参数：$url $other
api_request()
{
    url="https://dnsapi.cn"
    url+="$1"
    shift
    curl -s -A "$USERAGENT" \
        -d login_email="$EMAIL" -d login_password="$PASSWORD" \
        -d format=json -d lang=en -d error_on_empty=no \
        $@ $url
}

# 获取当前外网 IP
get_current_ip()
{
    curl -s http://ifconfig.me/ip | grep '^[0-9]\+\(\.[0-9]\+\)\{3\}$'
}

# 获取 Domain ID
# 参数：$domain
get_domain_id()
{
    api_request "/Domain.List" | \
    jsawk -q "..domains.[?name='$1']..id"
}

# 获取 Record ID
# 参数：$domain_id $sub_domain
get_record_id()
{
    api_request "/Record.List" -d domain_id="$1" | \
    jsawk -q "..records.[?name='$2']..id"
}

# 创建新记录
# 参数：$domain_id $sub_domain $record_type $record_line $value
record_create()
{
    local result=$(
        api_request "/Record.Create" \
            -d domain_id="$1" \
            -d sub_domain="$2" \
            -d record_type="$3" \
            -d record_line="$4" \
            -d value="$5")
    if [ $? != 0 ]
    then
        return -1
    fi

    local code=$(echo $result | jsawk -q "..status..code" | remove_quote)
    local message=$(echo $result | jsawk -q "..status..message" | remove_quote)
    echo "$message"
    if [ "$code" = "1" ]
    then
        return 0
    else
        return -$code
    fi
}

# 修改存在的记录
# 参数：$domain_id $record_id $sub_domain $record_type $record_line $value
record_modify()
{
    local result=$(
        api_request "/Record.Modify" \
            -d domain_id="$1" \
            -d record_id="$2" \
            -d sub_domain="$3" \
            -d record_type="$4" \
            -d record_line="$5" \
            -d value="$6")
    if [ $? != 0 ]
    then
        return -1
    fi

    local code=$(echo $result | jsawk -q "..status..code" | remove_quote)
    local message=$(echo $result | jsawk -q "..status..message" | remove_quote)
    echo "$message"
    if [ "$code" = "1" ]
    then
        return 0
    else
        return $code
    fi
}

# 日志记录
log()
{
    echo [$(date +%Y-%m-%dT%H:%M:%S)] "$1"
} >> $LOGFILE

# 自动检测IP变化
check_and_update()
{
    trap '' HUP
    trap 'log terminate; exit 0' TERM

    while true
    do
        sleep $INTERVAL
        new_ip=$(get_current_ip)
        if [ $? != 0 ]
        then
            continue
        fi
        if [ "$new_ip" != "$current_ip" -a "$new_ip" != "" ]
        then
            log "detect ip change: $current_ip => $new_ip"
            current_ip="$new_ip"
            # 如果IP发生变化则修改
            result=$(record_modify $domain_id $record_id \
                $SUBDOMAIN A 默认 $current_ip)
            result_code=$?
            log "modify result: $result_code, $result"
        fi
    done
}

domain_id=$(get_domain_id $DOMAIN)
echo domain id: $domain_id
record_id=$(get_record_id $domain_id $SUBDOMAIN | remove_quote)
echo record id: $record_id
current_ip=$(get_current_ip)
echo current ip: $current_ip

if [ "$record_id" = "" ]
then
    # 记录不存在则创建
    result=$(record_create $domain_id \
        $SUBDOMAIN A 默认 $current_ip)
    result_code=$?
else
    # 记录存在则更新一次
    result=$(record_modify $domain_id $record_id \
        $SUBDOMAIN A 默认 $current_ip)
    result_code=$?
fi

echo result: $result_code, $result

check_and_update &
log "daemon started, pid: $!"