From 89ce1ae672d3189bf4fa4697354a892183ca3df7 Mon Sep 17 00:00:00 2001
From: Rich O <rich@rickelobe.com>
Date: Sat, 6 Feb 2021 13:57:48 -0500
Subject: [PATCH] Added comparison of current pub IP to the DNS record.  DNS
 Record will only be updated if the record does not match the current public
 IP.

---
 dns_updater.sh | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/dns_updater.sh b/dns_updater.sh
index 5e5e8a8..81010b1 100644
--- a/dns_updater.sh
+++ b/dns_updater.sh
@@ -10,19 +10,27 @@ RECORD_NAME="example.com"
 RECORD_TYPE="A"
 TTL=1
 
+#Get the current IP address for the DNS record
+RECORD_IP="$(dig @1.1.1.1 $RECORD_NAME | grep $RECORD_NAME | grep -v ';' | awk '{ print $5} ')"
+
 IP="$(curl -s http://ipinfo.io/ip 2> /dev/null)"
 
 DATE=$(date +%Y%m%d-%H%M%S)
 
-RESPONSE=$(curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records/$RECORD_ID" \
-        -H "X-Auth-Email: $AUTH_EMAIL" \
-        -H "X-Auth-Key: $CLOUDFLARE_API_KEY" \
-        -H "Content-Type: application/json" \
-        --data '{"type":"$RECORD_TYPE","name":"'$RECORD_NAME'","content":"'$IP'","ttl":'$TTL'}')
+#If the RECORD_IP and IP do not match, then we need to update the record information.
+if [ "$RECORD_IP" != "$IP" ]; then
+        RESPONSE=$(curl -s -X PUT "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records/$RECORD_ID" \
+                -H "X-Auth-Email: $AUTH_EMAIL" \
+                -H "X-Auth-Key: $CLOUDFLARE_API_KEY" \
+                -H "Content-Type: application/json" \
+                --data '{"type":"$RECORD_TYPE","name":"'$RECORD_NAME'","content":"'$IP'","ttl":'$TTL'}')
 
-if [ $(echo "$RESPONSE" | grep '"success":true' | wc -l) -eq 1 ]; then
-        echo "$DATE|IP:$IP|CF Update: Success"
+        if [ $(echo "$RESPONSE" | grep '"success":true' | wc -l) -eq 1 ]; then
+                echo "$DATE|Record IP: $RECORD_IP|Pub IP: $IP|CF Update: Success"
+        else
+                echo "$DATE|Record IP: $RECORD_IP|Pub IP: $IP|CF Update: Failure"
+                echo "Response: $RESPONSE"
+        fi
 else
-        echo "$DATE|IP:$IP|CF Update: Failure"
-        echo "Response: $RESPONSE"
+        echo "$DATE|Record IP: $RECORD_IP|Pub IP: $IP|CF Update: Skipped"
 fi