Attempting to update Amazon Route53 using a script, but domain is not being updated

I have several Amazon EC2 instances, running Ubuntu 10.04, with which I'd like to use Amazon's Route53. I setup a script as described in Shlomo Swidler's article, but I'm still missing something.

When the script runs, it doesn't return any output, which I initially assumed meant it ran correctly. However, when I check the DNS records using MyR53DNS, there are no entrie开发者_StackOverflows for my instances. Here's my script:

#!/bin/tcsh -f

set root=`dirname $0`
setenv EC2_HOME /usr/lib/ec2-api-tools
setenv EC2_CERT /etc/cron.route53/ec2_x509_cert.pem
setenv EC2_PRIVATE_KEY /etc/cron.route53/ec2_x509_private.pem
setenv AWS_ACCESS_KEY_ID myaccesskeyid
setenv AWS_SECRET_ACCESS_KEY myaccesskey

/usr/bin/ec2-describe-instances | \
perl -ne '/^INSTANCE\s+(i-\S+).*?(\S+\.amazonaws\.com)/ \
and do { $dns = $2; print "$1 $dns\n" }; /^TAG.+\sShortName\s+(\S+)/ \
and print "$1 $dns\n"' | \
perl -ane 'print "$F[0] CNAME $F[1] --replace\n"' | \
xargs -n 4 /etc/cron.route53/cli53/cli53.py \
rrcreate -x 60 mydomain.com

Does anyone see a problem with this script? If its not the script, what else could be preventing my Route53 domain from being updated?

I am using the Security Groups to IP-restrict the instances. I've tried opening port 53, but that didn't seem to have an effect. Is there another port that Route53 uses?

I'd appreciate any help or guidance the StackOverflow community can offer. Let me know if you need any further info.

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I posted this question in several different places looking for an answer. I finally found it on the StackExchange Unix & Linux site.

I hope this helps someone else out there.