I was surprised to find that CloudFlare created AAAA records for my domains when my server doesn't support IPv6 at all. Reading the CloudFlare community I found the only way to disable the "feature" is via the API.
I made a bash shell script so I could do it again easily in the future, which I'm happy to share below.
The following script can disable (or enable) AAAA records on all (or one) of your CloudFlare domains in your account. Copy it into a file and execute it. You should install the utilities curl and jq first, e.g. with sudo apt-get install curl jq on Ubuntu. Your email address and API key are not stored in the script or on the server for maximum security.
#!/bin/bash
# Turn CloudFlare AAAA records on or off
echo "Enter CloudFlare account email:"
read EMAIL
echo "Enter key from Dashboard > My Profile > API Tokens > Global API Key:"
read KEY
# https://api.cloudflare.com/#zone-list-zones
curl -s -X GET "https://api.cloudflare.com/client/v4/zones" \
-H "X-Auth-Email: $EMAIL" \
-H "X-Auth-Key: $KEY" \
-H "Content-Type: application/json" \
> /tmp/cf-tmp
jq -r '.result[] | .id + " " + .name' /tmp/cf-tmp > /tmp/cf-zones
rm /tmp/cf-tmp
I=1
for NAME in $(cat /tmp/cf-zones | awk '{print $2}'); do
echo $I. $NAME
let I+=1
done
echo "$I. ALL"
echo -n "Choose domain to modify [$I]: "
read SELECT
ZONES=()
if [ -z "$SELECT" ] || [ "$SELECT" -eq "$I" ]; then
SELECT=$I
while read LINE; do ZONES+=("$LINE"); done < /tmp/cf-zones
else
ZONES+=("$(sed "${SELECT}q;d" /tmp/cf-zones)")
fi
echo "Selected: $SELECT"
echo "What do you want to do with the AAAA records?"
echo "1. Turn off"
echo "2. Turn on"
echo -n "Make a selection [1]: "
read SELECT
if [ -z "$SELECT" ] || [ "$SELECT" -eq "1" ]; then SELECT=1; VAL=off; else VAL=on; fi
echo "Selected: $SELECT"
for ((I = 0; I < ${#ZONES[@]}; I++)); do
ID=$(echo ${ZONES[$I]} | awk '{print $1}')
NAME=$(echo ${ZONES[$I]} | awk '{print $2}')
echo -n "Turning $VAL AAAA records for $NAME... "
# https://api.cloudflare.com/#zone-settings-change-ipv6-setting
curl -s -X PATCH "https://api.cloudflare.com/client/v4/zones/$ID/settings/ipv6" \
-H "X-Auth-Email: $EMAIL" \
-H "X-Auth-Key: $KEY" \
-H "Content-Type: application/json" \
--data "{\"value\":\"$VAL\"}" > /tmp/cf-tmp
if [ "`jq .success /tmp/cf-tmp`" == "true" ]; then
echo "OK";
else
echo "ERROR:"
cat /tmp/cf-tmp
fi
done
rm /tmp/cf-tmp
rm /tmp/cf-zones