route53-identity.sh

#!/bin/bash
#
# Updates a hosted zone in Route53 to point to the current IP address
# of this host.  
#
# Usage: route53-identity.sh ZTDR0AEDW myhost.mydomain.com
#

ZONE_ID=$1
DOMAIN_NAME=$2
TMP_FILE=/tmp/aws.json
IP_ADDR=$(ifconfig | awk '/inet addr/{print substr($2,6)}' | grep -v 127.0.0.1 | xargs echo -n)
TEMPLATE='
{
  "Comment": "",
  "Changes": [
      {
          "Action": "UPSERT",
          "ResourceRecordSet": {
              "Name": "",
              "Type": "A",
              "TTL": 300,
              "ResourceRecords": [
                  {
                      "Value": ""
                  }
               ]
          }
      }
  ]
}
'

rm -f $TMP_FILE
echo "$TEMPLATE" | python -c "
import json
import sys

obj=json.load(sys.stdin)
obj['Changes'][0]['ResourceRecordSet']['Name'] = '$DOMAIN_NAME.'
obj['Changes'][0]['ResourceRecordSet']['ResourceRecords'][0]['Value'] = '$IP_ADDR'

print json.dumps(obj)" > $TMP_FILE
aws route53 change-resource-record-sets --hosted-zone-id $ZONE_ID --change-batch file://$TMP_FILE
rm -f $TMP_FILE