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Bash script that checks for IP change and updates Route53
#!/bin/bash
# Usage: Launch in the background and pass RECORD_SET_NAME (e.g. sub.example.com.)
# as a first argument for the Route53 record. Log file can be found at /var/tmp/r53-record.log
NOTIFY_DIR=/var/tmp
LOG_FILE=${NOTIFY_DIR}/r53-record.log
CURR_IP_FILE=${NOTIFY_DIR}/ip.out
TMP_IP_FILE=${NOTIFY_DIR}/ip.tmp
IP_LKP_URL=https://ifconfig.me/ip
RECORD_SET_FILE=${NOTIFY_DIR}/r53-record-set.json
RECORD_SET_NAME=${1}
RECORD_SET_TTL=300
function create_record_json {
cat << EOF > ${RECORD_SET_FILE}
{
"Changes": [
{
"Action": "UPSERT",
"ResourceRecordSet": {
"Name": "${RECORD_SET_NAME}",
"Type": "A",
"TTL": ${RECORD_SET_TTL},
"ResourceRecords": [
{
"Value": "${1}"
}
]
}
}
]
}
EOF
}
function update_route53_record {
local new_ip=$(cat ${CURR_IP_FILE})
create_record_json "${new_ip}"
local resp=$(aws route53 change-resource-record-sets --hosted-zone-id ${HOSTED_ZONE_ID} --change-batch file://${RECORD_SET_FILE})
echo "Updated route53 record:" >> ${LOG_FILE}
echo "${resp}" >> ${LOG_FILE}
}
create_record_json "127.0.0.1"
curl -sf $IP_LKP_URL > $CURR_IP_FILE
while [[ true ]]; do
printf $(curl -sf $IP_LKP_URL) > $TMP_IP_FILE
IP_DIFF=$(diff -w $TMP_IP_FILE $CURR_IP_FILE)
if [[ "$IP_DIFF" != "" ]]; then
echo "We have a new IP: $(cat $TMP_IP_FILE)" >> ${LOG_FILE}
cat $TMP_IP_FILE > $CURR_IP_FILE
update_route53_record
fi
sleep 300s
done
@jeffrade
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jeffrade commented Aug 17, 2020

This script now has a home at https://github.com/jeffrade/proxy-server

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