Amazonサーバーから受信したIPに基づいてCloudflare上のIPを変更および更新するロボットを構築する

curl -s http://169.254.169.254/latest/meta-data/public-ipv4

curl -s http://169.254.169.254/latest/meta-data/ipv6

aws ec2 describe-instances --instance-ids i-0123456789abcdef --query "Reservations[].Instances[].PublicIpAddress" --output text

curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=example.com" -H "Authorization: Bearer $CF_API_TOKEN" -H "Content-Type: application/json" | jq -r '.result[0].id'

curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records?name=vpn.example.com" -H "Authorization: Bearer $CF_API_TOKEN" -H "Content-Type: application/json" | jq -r '.result[0].id'

#!/usr/bin/env bash
set -e
CF_TOKEN="---FROM SECRETS MANAGER OR ENV---"
ZONE_ID="your_zone_id"
RECORD_NAME="vpn.example.com"
RECORD_ID="your_record_id"
PROXY=false
TTL=120

get_ip() {
  curl -s http://169.254.169.254/latest/meta-data/public-ipv4
}

current_ip=$(get_ip)
old_ip_file="/var/run/current_ip_${RECORD_NAME}"

if [ -f "$old_ip_file" ]; then
  old_ip=$(cat "$old_ip_file")
else
  old_ip=""
fi

if [ "$current_ip" = "" ]; then
  echo "No public IP found" >&2
  exit 1
fi

if [ "$current_ip" != "$old_ip" ]; then
  echo "Updating Cloudflare DNS from $old_ip to $current_ip"
  payload=$(jq -n --arg type "A" --arg name "$RECORD_NAME" --arg content "$current_ip" --argjson proxied $PROXY --argjson ttl $TTL '{type:$type, name:$name, content:$content, proxied:$proxied, ttl:$ttl}')
  resp=$(curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records/$RECORD_ID" -H "Authorization: Bearer $CF_TOKEN" -H "Content-Type: application/json" --data "$payload")
  success=$(echo "$resp" | jq -r '.success')
  if [ "$success" = "true" ]; then
    echo "$current_ip" > "$old_ip_file"
    echo "Update successful"
  else
    echo "Update failed: $resp" >&2
    exit 2
  fi
else
  echo "IP unchanged ($current_ip)"
fi

requests
boto3

import os, requests, json
CF_TOKEN = os.environ['CF_TOKEN']
ZONE_ID = os.environ['ZONE_ID']
RECORDS = json.loads(os.environ.get('RECORDS_JSON', '[]'))

HEADERS = {
    "Authorization": f"Bearer {CF_TOKEN}",
    "Content-Type": "application/json"
}

def get_ec2_public_ip():
    try:
        r = requests.get("http://169.254.169.254/latest/meta-data/public-ipv4", timeout=2)
        if r.ok:
            return r.text.strip()
    except:
        pass
    return None

def find_record_id(name, type="A"):
    url = f"https://api.cloudflare.com/client/v4/zones/{ZONE_ID}/dns_records?name={name}&type={type}"
    r = requests.get(url, headers=HEADERS)
    data = r.json()
    if data.get("success") and data["result"]:
        return data["result"][0]["id"]
    return None

def update_record(record_id, name, ip, type="A", ttl=120, proxied=False):
    url = f"https://api.cloudflare.com/client/v4/zones/{ZONE_ID}/dns_records/{record_id}"
    payload = {"type": type, "name": name, "content": ip, "ttl": ttl, "proxied": proxied}
    r = requests.put(url, headers=HEADERS, json=payload)
    return r.json()

def lambda_handler(event, context=None):
    ip = get_ec2_public_ip()
    if not ip:
        print("No public IP found")
        return
    for rec in RECORDS:
        name = rec["name"]
        typ = rec.get("type","A")
        rec_id = find_record_id(name, typ)
        if not rec_id:
            print(f"No record id for {name}")
            continue
        resp = update_record(rec_id, name, ip, typ, rec.get("ttl",120), rec.get("proxied",False))
        print(resp)

if __name__ == "__main__":
    lambda_handler(None)