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@benkulbertis
Last active April 28, 2024 16:35
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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
@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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