Automatically update your CloudFlare DNS record to the IP, Dynamic DNS for Cloudflare

cloudflare-ddns.sh

#!/usr/bin/env bash

# The zone ID of the domain
CF_ZONE_ID=

# The email of the user and the global api key
CF_USER_EMAIL=
CF_GLOBAL_API_KEY=

# A generated API key with the permission "Zone.DNS"
CF_API_KEY=

# The hostname to update
CF_HOSTNAME=

# GET ZONE ID
## USAGE WITH GLOBAL API KEY
curl -X GET "https://api.cloudflare.com/client/v4/zones/$CF_ZONE_ID/dns_records?type=A&name=$CF_HOSTNAME&match=all" \
     -H "X-Auth-Email: $CF_USER_EMAIL" \
     -H "X-Auth-Key: $GLOBAL_API" \
     -H "Content-Type: application/json"
## USAGE WITH API KEY
curl -X GET "https://api.cloudflare.com/client/v4/zones/$CF_ZONE_ID/dns_records?type=A&name=$CF_HOSTNAME&match=all" \
     -H "Authorization: Bearer $API" \
     -H "Content-Type: application/json"

json["success"] = true
CF_DNS_ID=json["result"][0]["id"]

# GET CURRENT IPv4
IPV4=$(curl https://api.ipify.org/)

# UPDATE IP ON CLOUDFLARE
## USAGE WITH GLOBAL API KEY
curl -X PATCH "https://api.cloudflare.com/client/v4/zones/$CF_ZONE_ID/dns_records/$CF_DNS_ID" \
     -H "X-Auth-Email: $CF_USER_EMAIL" \
     -H "X-Auth-Key: $GLOBAL_API" \
     -H "Content-Type: application/json" \
     --data '{"content":"'"$IPV4"'"}'
## USAGE WITH API KEY
curl -X PATCH "https://api.cloudflare.com/client/v4/zones/$CF_ZONE_ID/dns_records/$CF_DNS_ID" \
     -H "Authorization: Bearer $API" \
     -H "Content-Type: application/json" \
     --data '{"content":"'"$IPV4"'"}'

json["success"] = true