cloudflare-ddns.sh

#!/bin/bash

# Forked from lifehome/systemd-cfddns/src/cfupdater-v4

# CHANGE THESE
auth_email="mail@example.com"           # The email used to login 'https://dash.cloudflare.com'
auth_key="xxxxx"   			# Top right corner, "My profile" > "Global API Key"
zone_identifier="xxxxx" 		# Can be found in the "Overview" tab of your domain
record_name="home.examlpe.com"          # Which record you want to be synced

# Fetch external IP address
ip=$(curl -s inet-ip.info)

# Seek for the current record on Cloudflare
record=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zone_identifier/dns_records?name=$record_name" \
        -H "X-Auth-Email: $auth_email" \
        -H "X-Auth-Key: $auth_key" \
        -H "Content-Type: application/json")


# Can't do anything without the record
record_count=$(echo $record | jq -r '.result_info.count')
if [ $record_count == 0  ]; then
        >&2 echo -e "[Cloudflare DDNS] Record does not exist, perhaps create one first?"
        exit 1
fi

# Extract existing IP address from the fetched record
old_ip=$(echo $record | jq -r '.result[0].content')
echo "[Cloudflare DDNS] Currently set to $old_ip"

# Compare if they're the same
if [ "$ip" == "$old_ip" ]; then
        echo "[Cloudflare DDNS] IP has not changed."
        exit 0
fi

# Extract record identifier from result
record_identifier=$(echo $record | jq -r '.result[0].id')

# Update IP address through Cloudflare API
update=$(curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$zone_identifier/dns_records/$record_identifier" \
        -H "X-Auth-Email: $auth_email" \
        -H "X-Auth-Key: $auth_key" \
        -H "Content-Type: application/json" \
        --data "{\"type\":\"A\",\"name\":\"$record_name\",\"content\":\"$ip\",\"ttl\":1}")

# Result
success=$(echo $update | jq -r '.success')


case "$success" in
"true")
        echo "[Cloudflare DDNS] IPv4 context '$ip' has been synced to Cloudflare.";;
*)
        >&2 echo -e "[Cloudflare DDNS] Update failed for $record_identifier. DUMPING RESULTS:\n$update"
        exit 1;;
esac