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#!/bin/bash
#
# This script requires xpath to parse part of the dnscurl.pl output
# on CentOS/RedHat/Amazon Linux:
#
# sudo yum install perl-XML-XPath
#
# also, dnscurl.pl (from http://aws.amazon.com/code/Amazon-Route-53/9706686376855511)
# expects your secrets to be in ~/.aws-secrets
# using a file format like this (from http://dmz.us/wp/wp-content/uploads/r53/aws-secrets.txt)
#
# %awsSecretAccessKeys = (
# "my-aws-account" => {
# id => "YOUR_ID_GOES_HERE_KEEP_THE_QUOTES",
# key => "YOUR_SECRET_KEY_GOES_HERE_KEEP_THE_QUOTES",
# },
# );
### User Settings (things you must set)
## Location of the dnscurl.pl script
DNSCurl="/path/to/route53DynDNS/dnscurl.pl"
## The host name you wish to update/create
myHostName="*"
## Zone/domain in which host (will) reside(s)
myDomainName="example.com"
##########################################
### Things you may want to set
## set the TTL for the new/updated A record
myTTL="600"
route53API="https://route53.amazonaws.com/2011-05-05"
route53APIDoc="https://route53.amazonaws.com/doc/2011-05-05/"
##########################################
### Thing you shouldn't change
## how long to wait after submitting a change
## before checking to see if it's state is
## INSYNC
sleepDelay=20
XPATH="xpath -e "
XPATH="xpath "
##########################################
### Code... don't change anything below.
## Get the Hosted Zone ID from Route 53
hostedZoneIDSearch="ListHostedZonesResponse/HostedZones/HostedZone[Name=\"$myDomainName.\"]/Id"
route53HostedZoneID=`$DNSCurl --keyname my-aws-account -- -s -H "Content-Type: text/xml; charset=UTF-8" -X GET $route53API/hostedzone 2>/dev/null | $XPATH $hostedZoneIDSearch 2>/dev/null |awk -F'[<|>]' '/Id/{print $3}' | cut -d/ -f3`
if [ -z $route53HostedZoneID ]; then
echo "Could not find zone '$myDomainName' in route 53"
# exit 1
fi
## Check to see if the A record already exists
currentARecordValueSearch="ListResourceRecordSetsResponse/ResourceRecordSets/ResourceRecordSet[Name=\"$myHostName.$myDomainName.\"]/ResourceRecords/ResourceRecord/Value"
if [ `echo $myHostName|grep "*"` ]; then
## Replace "*"
currentARecordValueSearch="ListResourceRecordSetsResponse/ResourceRecordSets/ResourceRecordSet[Name=\"${myHostName/\*/\\052}.$myDomainName.\"]/ResourceRecords/ResourceRecord/Value"
fi
currentARecordValue=`$DNSCurl --keyname my-aws-account -- -s -H "Content-Type: text/xml; charset=UTF-8" -X GET $route53API/hostedzone/$route53HostedZoneID/rrset 2>/dev/null | $XPATH $currentARecordValueSearch 2>/dev/null | awk -F'[<|>]' '/Value/{print $3}' | cut -d/ -f3`
## And if not, set a flag to create the A record
if [ -z $currentARecordValue ]; then
echo "Could not find A RR for $myHostName.$myDomainName."
echo "Creating initial record"
CREATE_INITIAL=true
fi
## Route 53 updates require the A record name, ttl and value for the delete.
## Fetch the TTL
currentARecordTTLSearch="ListResourceRecordSetsResponse/ResourceRecordSets/ResourceRecordSet[Name=\"$myHostName.$myDomainName.\"]/TTL"
if [ `echo $myHostName|grep "*"` ]; then
## Replace "*"
currentARecordTTLSearch="ListResourceRecordSetsResponse/ResourceRecordSets/ResourceRecordSet[Name=\"${myHostName/\*/\\052}.$myDomainName.\"]/TTL"
fi
currentARecordTTL=`$DNSCurl --keyname my-aws-account -- -s -H "Content-Type: text/xml; charset=UTF-8" -X GET $route53API/hostedzone/$route53HostedZoneID/rrset 2>/dev/null | $XPATH $currentARecordTTLSearch 2>/dev/null | awk -F'[<|>]' '/TTL/{print $3}' | cut -d/ -f3`
if [ -z $currentARecordTTL ]; then
CREATE_INITIAL=true
fi
## Get the public IP
myPublicIP=`wget -q -O - checkip.dyndns.org|sed -e 's/.*Current IP Address: //' -e 's/<.*$//'`
if [ -z $myPublicIP ]; then
echo "Failed to look up public IP address"
exit 1
fi
## Generate a timestamp for the update
timestamp=`date`
## Give some status
echo "Public IP address is: $myPublicIP"
## If the DNS A RR matched the public IP, exit
if [[ "$myPublicIP" == "$currentARecordValue" ]]; then
echo "Current A RR IP address is: $currentARecordValue"
echo "No need to update A record."
exit 0
fi
## Get a temp file
tmpxml=`mktemp`
#CREATE_INITIAL=false
## Determine if the A RR is to be created or updated (deleted/created)
if [ $CREATE_INITIAL ]; then
echo "Creating A record for $myHostName.$myDomainName. to be $myPublicIP"
cat <<UPDATE-XML > $tmpxml
<?xml version="1.0" encoding="UTF-8"?>
<ChangeResourceRecordSetsRequest xmlns="$route53APIDoc">
<ChangeBatch>
<Comment>Create Record for $myHostName.$myDomainName at $timestamp</Comment>
<Changes>
<Change>
<Action>CREATE</Action>
<ResourceRecordSet>
<Name>$myHostName.$myDomainName.</Name>
<Type>A</Type>
<TTL>$myTTL</TTL>
<ResourceRecords>
<ResourceRecord>
<Value>$myPublicIP</Value>
</ResourceRecord>
</ResourceRecords>
</ResourceRecordSet>
</Change>
</Changes>
</ChangeBatch>
</ChangeResourceRecordSetsRequest>
UPDATE-XML
else
echo "A Record for $myHostName.$myDomainName. is $currentARecordValue with ttl: $currentARecordTTL"
echo "Updating A record for $myHostName.$myDomainName. to be $myPublicIP with ttl $myTTL"
cat <<UPDATE-XML > $tmpxml
<?xml version="1.0" encoding="UTF-8"?>
<ChangeResourceRecordSetsRequest xmlns="$route53APIDoc">
<ChangeBatch>
<Comment>Update Record for $myHostName.$myDomainName at $timestamp</Comment>
<Changes>
<Change>
<Action>DELETE</Action>
<ResourceRecordSet>
<Name>$myHostName.$myDomainName.</Name>
<Type>A</Type>
<TTL>$currentARecordTTL</TTL>
<ResourceRecords>
<ResourceRecord>
<Value>$currentARecordValue</Value>
</ResourceRecord>
</ResourceRecords>
</ResourceRecordSet>
</Change>
<Change>
<Action>CREATE</Action>
<ResourceRecordSet>
<Name>$myHostName.$myDomainName.</Name>
<Type>A</Type>
<TTL>$myTTL</TTL>
<ResourceRecords>
<ResourceRecord>
<Value>$myPublicIP</Value>
</ResourceRecord>
</ResourceRecords>
</ResourceRecordSet>
</Change>
</Changes>
</ChangeBatch>
</ChangeResourceRecordSetsRequest>
UPDATE-XML
fi
## Do the actual create/update
updateResponse=`$DNSCurl --keyname my-aws-account -- -s -H "Content-Type: text/xml; charset=UTF-8" -X POST --upload-file $tmpxml $route53API/hostedzone/$route53HostedZoneID/rrset 2>/dev/null`
## And record the response
updateResponseStatus=`echo $updateResponse | $XPATH 'ChangeResourceRecordSetsResponse/ChangeInfo/Status' 2>/dev/null |awk -F'[<|>]' '/Status/{print $3}' | cut -d/ -f3`
## Make sure the response is "PENDING"
## Otherwise, error
if [[ "$updateResponseStatus" != "PENDING" ]]; then
echo "Update is not in PENDING status"
echo $updateResponse
rm -f $tmpxml
exit 1
fi
## Get the transaction ID
updateResponseID=`echo $updateResponse | $XPATH 'ChangeResourceRecordSetsResponse/ChangeInfo/Id' 2>/dev/null | awk -F'[<|>]' '/Id/{print $3}' | cut -d/ -f3`
echo "Got update status ID $updateResponseID with status $updateResponseStatus"
echo "Pausing $sleepDelay seconds to allow for sync"
sleep $sleepDelay
## Check for status
statusCheckResponse=`$DNSCurl --keyname my-aws-account -- -s -H "Content-Type: text/xml; charset=UTF-8" -X GET $route53API/change/$updateResponseID 2>/dev/null`
statusCheckResponseStatus=`echo $statusCheckResponse | $XPATH 'GetChangeResponse/ChangeInfo/Status' 2>/dev/null | awk -F'[<|>]' '/Status/{print $3}' | cut -d/ -f3`
if [[ "$statusCheckResponseStatus" != "INSYNC" ]]; then
echo "update failed!"
echo "Status is $statusCheckResponseStatus"
rm -f $tmpxml
exit 1
fi
## Success, clean up
echo "Success!"
rm -f $tmpxml
exit 0
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