aws-vpc-route53.in

#!@BASH_SHELL@
#
#   Copyright 2017 Amazon.com, Inc. and its affiliates. All Rights Reserved.
#   Licensed under the MIT License.
#
#  Copyright 2017 Amazon.com, Inc. and its affiliates

# Permission is hereby granted, free of charge, to any person obtaining a copy of
# this software and associated documentation files (the "Software"), to deal in
# the Software without restriction, including without limitation the rights to
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# of the Software, and to permit persons to whom the Software is furnished to do
# so, subject to the following conditions:

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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.

#
#
#
# OCF resource agent to move an IP address within a VPC in the AWS
# Written by Stefan Schneider , Martin Tegmeier (AWS)
# Based on code of Markus Guertler#
#
#
# OCF resource agent to move an IP address within a VPC in the AWS
# Written by Stefan Schneider (AWS) , Martin Tegmeier (AWS)
# Based on code of Markus Guertler (SUSE)
#
# Mar. 15, 2017, vers 1.0.2

#######################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

OCF_RESKEY_ttl_default=10

: ${OCF_RESKEY_ttl:=${OCF_RESKEY_ttl_default}}

#######################################################################

usage() {
	cat <<-EOT
	usage: $0 {start|stop|status|monitor|validate-all|meta-data}
	EOT
}

metadata() {
cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="aws-vpc-route53">
<version>1.0</version>
<longdesc lang="en">
Update Route53 record of Amazon Webservices EC2 by updating an entry in a
hosted zone ID table.

AWS instances will require policies which allow them to update Route53 ARecords:
{
	"Version": "2012-10-17",
	"Statement": [
		{
			"Sid": "Stmt1471878724000",
			"Effect": "Allow",
			"Action": [
				"route53:ChangeResourceRecordSets",
				"route53:GetChange",
				"route53:ListResourceRecordSets",
			],
			"Resource": [
				"*"
			]
		}
	]
}

Example Cluster Configuration:

Use a configuration in "crm configure edit" which looks as follows. Replace
hostedzoneid, fullname and profile with the appropriate values:

primitive res_route53 ocf:heartbeat:aws-vpc-route53 \
		params hostedzoneid=EX4MPL3EX4MPL3 fullname=service.cloud.example.corp. profile=cluster \
		op start interval=0 timeout=180 \
		op stop interval=0 timeout=180 \
		op monitor interval=300 timeout=180 \
		meta target-role=Started
</longdesc>
<shortdesc lang="en">Update Route53 VPC record for AWS EC2</shortdesc>
<parameters>
<parameter name="hostedzoneid" required="1">
<longdesc lang="en">
Hosted zone ID of Route 53. This is the table of
the Route 53 record.
</longdesc>
<shortdesc lang="en">AWS hosted zone ID</shortdesc>
<content type="string" default="" />
</parameter>
<parameter name="fullname" required="1">
<longdesc lang="en">
The full name of the service which will host the IP address.
Example: service.cloud.example.corp.
Note: The trailing dot is important to Route53!
</longdesc>
<shortdesc lang="en">Full service name</shortdesc>
<content type="string" default="" />
</parameter>
<parameter name="ttl" required="0">
<longdesc lang="en">
Time to live for Route53 ARECORD
</longdesc>
<shortdesc lang="en">ARECORD TTL</shortdesc>
<content type="string" default="${OCF_RESKEY_ttl_default}" />
</parameter>
<parameter name="profile" required="1">
<longdesc lang="en">
The name of the AWS CLI profile of the root account. This
profile will have to use the "text" format for CLI output.
The file /root/.aws/config should have an entry which looks
like:

  [profile cluster]
	region = us-east-1
	output = text

"cluster" is the name which has to be used in the cluster
configuration. The region has to be the current one. The
output has to be "text".
</longdesc>
<shortdesc lang="en">AWS Profile Name</shortdesc>
<content type="string" default="" />
</parameter>
</parameters>
<actions>
<action name="start" timeout="180s" />
<action name="stop" timeout="180s" />
<action name="monitor" depth="0" timeout="180s" interval="300s" />
<action name="validate-all" timeout="5s" />
<action name="meta-data" timeout="5s" />
</actions>
</resource-agent>
END
}

r53_validate() {
	ocf_log debug "function: validate"

	# Check for required binaries
	ocf_log debug "Checking for required binaries"
	for command in curl dig; do
		check_binary "$command"
	done

	# Full name
	[[ -z "$OCF_RESKEY_fullname" ]] && ocf_log error "Full name parameter not set $OCF_RESKEY_fullname!" && exit $OCF_ERR_CONFIGURED

	# Hosted Zone ID
	[[ -z "$OCF_RESKEY_hostedzoneid" ]] && ocf_log error "Hosted Zone ID parameter not set $OCF_RESKEY_hostedzoneid!" && exit $OCF_ERR_CONFIGURED

	# profile
	[[ -z "$OCF_RESKEY_profile" ]] && ocf_log error "AWS CLI profile not set $OCF_RESKEY_profile!" && exit $OCF_ERR_CONFIGURED

	# TTL
	[[ -z "$OCF_RESKEY_ttl" ]] && ocf_log error "TTL not set $OCF_RESKEY_ttl!" && exit $OCF_ERR_CONFIGURED

	ocf_log debug "Testing aws command"
	aws --version 2>&1
	if [ "$?" -gt 0 ]; then
		ocf_log error "Error while executing aws command as user root! Please check if AWS CLI tools (Python flavor) are properly installed and configured." && exit $OCF_ERR_INSTALLED
	fi
	ocf_log debug "ok"

	if [ -n "$OCF_RESKEY_profile" ]; then
		AWS_PROFILE_OPT="--profile $OCF_RESKEY_profile --cli-connect-timeout 10"
	else
		AWS_PROFILE_OPT="--profile default --cli-connect-timeout 10"
	fi

	return $OCF_SUCCESS
}

r53_monitor() {
	#
	# For every start action the agent  will call Route53 API to check for DNS record
	# otherwise it will try to get results directly bu querying the DNS using "dig".
	# Due to complexity in some DNS architectures "dig" can fail, and if this happens
	# the monitor will fallback to the Route53 API call.
	#
	# There will be no failure, failover or restart of the agent if the monitor operation fails
	# hence we only return $OCF_SUCESS in this function
	#
	# In case of the monitor operation detects a wrong or non-existent Route53 DNS entry
	# it will try to fix the existing one, or create it again
	#
	#
	ARECORD=""
	IPREGEX="^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$"
	r53_validate
	ocf_log debug "Checking Route53 record sets"
	#
	IPADDRESS="$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)"
	#
	if [ "$__OCF_ACTION" = "start" ] || ocf_is_probe ; then
		#
		cmd="aws $AWS_PROFILE_OPT route53 list-resource-record-sets --hosted-zone-id $OCF_RESKEY_hostedzoneid --query ResourceRecordSets[?Name=='$OCF_RESKEY_fullname']"
		ocf_log debug "Route53 Agent Starting or probing - executing monitoring API call: $cmd"
		ARECORD="$($cmd | grep RESOURCERECORDS | awk '{ print $2 }')"
	else
		#
		cmd="dig +retries=3 +time=5 +short $OCF_RESKEY_fullname 2>/dev/null"
		ocf_log debug "executing monitoring command : $cmd"
		ARECORD="$($cmd)"
		rc=$?
		ocf_log debug "dig return code: $rc"
		#
		if  [[ ! $ARECORD =~ $IPREGEX ]] || [ $rc -ne 0 ]; then
			ocf_log info "Fallback to Route53 API query due to DNS resolution failure"
			cmd="aws $AWS_PROFILE_OPT route53 list-resource-record-sets --hosted-zone-id $OCF_RESKEY_hostedzoneid --query ResourceRecordSets[?Name=='$OCF_RESKEY_fullname']"
			ocf_log debug "executing monitoring API call: $cmd"
			CLIRES="$($cmd 2>&1)"
			rc=$?
			ocf_log debug "awscli return code: $rc"
			if [ $rc -ne 0 ]; then
				ocf_log info "Route53 API returned an error: $CLIRES"
				ocf_log info "Monitor skipping cluster action due to API call error"
				return $OCF_SUCCESS
			fi
			ARECORD=$(echo $CLIRES | grep RESOURCERECORDS | awk '{ print $5 }')
		fi
		#
	fi
	ocf_log debug "Route53 DNS record pointing $OCF_RESKEY_fullname to IP address $ARECORD"
	#
	if [ "$ARECORD" == "$IPADDRESS" ]; then
		ocf_log debug "Route53 DNS record $ARECORD found"
		return $OCF_SUCCESS
	elif [[ $ARECORD =~ $IPREGEX ]] && [ "$ARECORD" != "$IPADDRESS" ]; then
		ocf_log info "Route53 DNS record points to a different host, setting DNS record on Route53 to this host"
		_update_record "UPSERT" "$IPADDRESS"
		return $OCF_SUCCESS
	else
		ocf_log info "No Route53 DNS record found, setting DNS record on Route53 to this host"
		_update_record "UPSERT" "$IPADDRESS"
		return $OCF_SUCCESS
	fi

	return $OCF_SUCCESS
}

_update_record() {
	#
	# This function is the one that will actually execute Route53's API call
	# and configure the DNS record using the correct API calls and parameters
	#
	# It creates a temporary JSON file under /tmp with the required API payload
	#
	# Failures in this function are critical and will cause the agent to fail
	#
	update_action="$1"
	IPADDRESS="$2"
	ocf_log info "Updating Route53 $OCF_RESKEY_hostedzoneid with $IPADDRESS for $OCF_RESKEY_fullname"
	ROUTE53RECORD="$(maketempfile)"
	if [ $? -ne 0 ] || [ -z "$ROUTE53RECORD" ]; then
		ocf_exit_reason "Failed to create temporary file for record update"
		exit $OCF_ERR_GENERIC
	fi
	cat >>"$ROUTE53RECORD" <<-EOF
	{
		  "Comment": "Update record to reflect new IP address for a system ",
		  "Changes": [
			  {
				  "Action": "$update_action",
				  "ResourceRecordSet": {
					  "Name": "$OCF_RESKEY_fullname",
					  "Type": "A",
					  "TTL": $OCF_RESKEY_ttl,
					  "ResourceRecords": [
						  {
							  "Value": "$IPADDRESS"
						  }
					  ]
				  }
			  }
		  ]
	}
	EOF
	cmd="aws --profile $OCF_RESKEY_profile route53 change-resource-record-sets --hosted-zone-id $OCF_RESKEY_hostedzoneid --change-batch file://$ROUTE53RECORD "
	ocf_log debug "Executing command: $cmd"
	CHANGEID=$($cmd | grep CHANGEINFO | awk -F'\t' '{ print $3 }' )
	ocf_log debug "Change id: $CHANGEID"
	rmtempfile $ROUTE53RECORD
	CHANGEID=$(echo $CHANGEID | cut -d'/' -f 3 | cut -d'"' -f 1 )
	ocf_log debug "Change id: $CHANGEID"
	STATUS="PENDING"
	MYSECONDS=8
	while [ "$STATUS" = 'PENDING' ]; do
		sleep $MYSECONDS
		STATUS="$(aws --profile $OCF_RESKEY_profile route53 get-change --id $CHANGEID | grep CHANGEINFO | awk -F'\t' '{ print $4 }' |cut -d'"' -f 2 )"
		ocf_log debug "Waited for $MYSECONDS seconds and checked execution of Route 53 update status: $STATUS "
	done
}

r53_stop() {
	#
	# Stop operation doesn't perform any API call or try to remove the DNS record
	# this mostly because this is not necessarily mandatory or desired
	# the start and monitor functions will take care of changing the DNS record
	# if the agent starts in a different cluster node
	#
	ocf_log info "Bringing down Route53 agent. (Will NOT remove Route53 DNS record)"
	return $OCF_SUCCESS
}

r53_start() {
	#
	# Start agent and config DNS in Route53
	#
	ocf_log info "Starting Route53 DNS update...."
	IPADDRESS="$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)"
	_update_record "UPSERT" "$IPADDRESS"
	return $OCF_SUCCESS
}

###############################################################################

case $__OCF_ACTION in
	usage|help)
		usage
		exit $OCF_SUCCESS
		;;
	meta-data)
		metadata
		exit $OCF_SUCCESS
		;;
	monitor)
		r53_monitor
		;;
	stop)
		r53_stop
		;;
	validate-all)
		r53_validate
		;;
	start)
		r53_start
		;;
	*)
		usage
		exit $OCF_ERR_UNIMPLEMENTED
		;;
esac