Cloudflare as Dynamic DNS

lwp-cloudflare-dyndns.sh

#!/bin/bash
# Cloudflare as Dynamic DNS
# From: https://letswp.io/cloudflare-as-dynamic-dns-raspberry-pi/
# Based on: https://gist.github.com/benkulbertis/fff10759c2391b6618dd/
# Original non-RPi article: https://phillymesh.net/2016/02/23/setting-up-dynamic-dns-for-your-registered-domain-through-cloudflare/

# Update these with real values
auth_email="[email protected]"
auth_key="global_api_key_goes_here" 
zone_name="example.com"
record_name="home.example.com"

# Don't touch these
ip=$(curl -s http://ipv4.icanhazip.com)
ip_file="ip.txt"
id_file="cloudflare.ids"
log_file="cloudflare.log"

# Keep files in the same folder when run from cron
current="$(pwd)"
cd "$(dirname "$(readlink -f "$0")")"

log() {
    if [ "$1" ]; then
        echo -e "[$(date)] - $1" >> $log_file
    fi
}

log "Check Initiated"

if [ -f $ip_file ]; then
    old_ip=$(cat $ip_file)
    if [ $ip == $old_ip ]; then
        log "IP has not changed."
        exit 0
    fi
fi

if [ -f $id_file ] && [ $(wc -l $id_file | cut -d " " -f 1) == 2 ]; then
    zone_identifier=$(head -1 $id_file)
    record_identifier=$(tail -1 $id_file)
else
    zone_identifier=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$zone_name" -H "X-Auth-Email: $auth_email" -H "X-Auth-Key: $auth_key" -H "Content-Type: application/json" | grep -Po '(?<="id":")[^"]*' | head -1 )
    record_identifier=$(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: $auth_key" -H "Content-Type: application/json"  | grep -Po '(?<="id":")[^"]*')
    echo "$zone_identifier" > $id_file
    echo "$record_identifier" >> $id_file
fi

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: $auth_key" -H "Content-Type: application/json" --data "{\"id\":\"$zone_identifier\",\"type\":\"A\",\"name\":\"$record_name\",\"content\":\"$ip\"}")

if [[ $update == *"\"success\":false"* ]]; then
    message="API UPDATE FAILED. DUMPING RESULTS:\n$update"
    log "$message"
    echo -e "$message"
    exit 1 
else
    message="IP changed to: $ip"
    echo "$ip" > $ip_file
    log "$message"
    echo "$message"
fi

Thank you @Firsh, works great!

As @giovanniferretti suggested, I changed out the email/key for the token. I'm getting a "sh: not: unknown operand" error followed by "IP changed to: [my ip]"

Any suggestions?
`zone_identifier=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$zone_name" -H "Authorization: Bearer $api_token" -H "Content-Type: application/json" | grep -Po '(?<="id":")[^"]' | head -1 )
record_identifier=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zone_identifier/dns_records?name=$record_name" -H "Authorization: Bearer $api_token" -H "Content-Type: application/json" | grep -Po '(?<="id":")[^"]')
echo "$zone_identifier" > $id_file
echo "$record_identifier" >> $id_file
fi

update=$(curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$zone_identifier/dns_records/$record_identifier" -H "Authorization: Bearer $api_token" -H "Content-Type: application/json" --data "{"id":"$zone_identifier","type":"A","name":"$record_name","content":"$ip"}")`

I've now switched to using this docker container:

version: "3"
services:
  cloudflare-ddns:
    image: oznu/cloudflare-ddns:latest
    restart: unless-stopped
    environment:
      - API_KEY=<cloudflare-api-key>
      - ZONE=example.com
      - SUBDOMAIN=subdomain
      - PROXIED=true

is it possible to use it without a subdomain?

I don't see why not.

If anyone is experiencing issues when trying to use this to update the primary A record for a domain, which may have other records associated with the same record_name, for example MX records, I suggest making the following modification:

record_identifier=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zone_identifier/dns_records?name=$record_name" -H "X-Auth-Email: $auth_email" -H "X-Auth-Key: $auth_key" -H "Content-Type: application/json" | grep -Po '(?<="id":")[^"]*')
Change to
record_identifier=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones/$zone_identifier/dns_records?name=$record_name&page=1&per_page=1" -H "X-Auth-Email: $auth_email" -H "X-Auth-Key: $auth_key" -H "Content-Type: application/json" | grep -Po '(?<="id":")[^"]*')
I discovered the issue by checking the .ids file and found 5 rows, when there should have only been 2 rows. By limiting to page=1 and per_page=1 it only returns the primary A record, and not MX records.

Nice, yeah that makes sense to receive a paged list of records if someone has a busy domain and the missing the one you wanted.

No working for me from a Raspberry Pi.

First attempts kept getting a URI error.

~/cf $ sudo ./lwp-cloudflare-dyndns.sh
API UPDATE FAILED. DUMPING RESULTS:
{"success":false,"errors":[{"code":7003,"message":"Could not route to \/zones\/dns_records, perhaps your object identifier is invalid?"},{"code":7000,"message":"No route for that URI"}],"messages":[],"result":null}

After self populating zone_identifier and record_identifier I get this error:

API UPDATE FAILED. DUMPING RESULTS:
{"success":false,"errors":[{"code":7001,"message":"Method PUT not available for that URI."}],"messages":[],"result":null}

Same result when I used a custom API token just for this script:

./lwp-cloudflare-dyndns.sh API UPDATE FAILED. DUMPING RESULTS: {"success":false,"errors":[{"code":7001,"message":"Method PUT not available for that URI."}],"messages":[],"result":null}

Not sure what old me had issues with, but just did this again and it worked. I don't even remember posting that comment. Blimey.

So thanks! (that docker version looks nice too)

Not sure what old me had issues with, but just did this again and it worked. I don't even remember posting that comment. Blimey.

I still use the script to this day, still on RPI, and it works fine. The only thing that will break it is when Cloudflare changes their API, to which we could react.

@tarasis I wish i could talk to 'old you' because i am getting that same error. as you.

Getting: API UPDATE FAILED. DUMPING RESULTS: {"success":false,"errors":[{"code":7003,"message":"Could not route to /zones/dns_records, perhaps your object identifier is invalid?"},{"code":7000,"message":"No route for that URI"}],"messages":[],"result":null}

Any idea? It is an account with multiple domains.

Hiya... did you ever get this to work?