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@benkulbertis
Last active April 28, 2023 02:12
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Cloudflare API v4 Dynamic DNS Update in Bash
#!/bin/bash
# CHANGE THESE
auth_email="user@example.com"
auth_key="c2547eb745079dac9320b638f5e225cf483cc5cfdda41" # found in cloudflare account settings
zone_name="example.com"
record_name="www.example.com"
# MAYBE CHANGE THESE
ip=$(curl -s http://ipv4.icanhazip.com)
ip_file="ip.txt"
id_file="cloudflare.ids"
log_file="cloudflare.log"
# LOGGER
log() {
if [ "$1" ]; then
echo -e "[$(date)] - $1" >> $log_file
fi
}
# SCRIPT START
log "Check Initiated"
if [ -f $ip_file ]; then
old_ip=$(cat $ip_file)
if [ $ip == $old_ip ]; then
echo "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
@niklasmato
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just a heads up everyone, apparently Cloudflare made a few changes to their API and I found out the hards way today (bit of a downtime). All you need to do is to add a space character ( ) in every regex when parsing a field.

specifically:
if [[ $record == *"\"count\":0"* ]]; then
needs to become
if [[ $record == *"\"count\": 0"* ]]; then

old_ip=$(echo "$record" | grep -Po '(?<="content":")[^"]*' | head -1)
to
old_ip=$(echo "$record" | grep -Po '(?<="content": ")[^"]*' | head -1)

*"\"success\":false"*)
has to become
*"\"success\": false"*)

Updated my scripts but still doesn't seem to work.
Anyone got it working again?

@flashtel
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grep -Po '(?<="id":")[^"]*')

change to

grep -Po '(?<="id": ")[^"]*')

@flashtel
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Why Cloudflare why do you do these things.

Thanks for the update

@AkimoA
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AkimoA commented May 2, 2020

tx guys for the update, was wondering what was going on !

@niklasmato
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Did they change something again? Scripts no longer seem to work..

@mrwhizzy
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@niklasmato, yes they did, I've uploaded an up-to-date version of the script on GitHub which will work a bit more reliably no matter if they have spaces after semicolons or not, plus it will also update multiple records.

@niklasmato
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@niklasmato, yes they did, I've uploaded an up-to-date version of the script on GitHub which will work a bit more reliably no matter if they have spaces after semicolons or not, plus it will also update multiple records.

Thank you for this!

@by-JohnChen
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by-JohnChen commented Dec 4, 2020

#!/bin/sh
#modify by: John Chen
# CHANGE THESE
zone_identifier="your_zone_id"
record_identifier="Your_record_iid"
auth_key="Your_auth_keys" # found in cloudflare account settings
zone_name="example.com"
record_name="www.example.com"

# MAYBE CHANGE THESE
ip=$(curl -s http://ipv4.icanhazip.com)
ip_file="ip.txt"
id_file="cloudflare.ids"
log_file="cloudflare.log"

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

# SCRIPT START
log "Check Initiated"

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

update=$(curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$zone_identifier/dns_records/$record_identifier" -H "Authorization: Bearer $auth_key" -H "Content-Type: application/json" --data "{"id":"$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

@0neday
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0neday commented Aug 31, 2021

change -H "X-Auth-Email: $auth_email" -H "X-Auth-Key: $auth_key" to -H "Authorization: Bearer $auth_key"
and
change use sed to instead of grep to parse json data
like
sed -E "s/.+\{\"id\":\"([a-f0-9]+)\".+\"type\":\"A\".+/\1/g"
and
if [ -f $id_file ] && [ -n $(sed -n '1p' $id_file) ] && [ -n $(sed -n '2p' $id_file) ]; then

and

success=$( echo $update | sed -E "s/.+\"success\":[ ]*([a-z]+).+/\1/g")


if [[ $success == "false" ]]; then
    message="API UPDATE FAILED. DUMPING RESULTS:\n$update"
    log "$message"
    echo -e "$message"
    exit 1 
else

check here

@lifehome
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lifehome commented Sep 3, 2021

Hi all,

Previously I have posted a bash/systemd version fork of this script in another gist, I have moved and updated the script to an actual repository, please kindly visit it instead at: https://github.com/lifehome/systemd-cfddns

Regards,
Ivan

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