#!/bin/sh
#
#
# OCF resource agent to move an IP address within a VPC in the AWS
#
# Copyright (c) 2017 Markus Guertler (SUSE)
# Based on code of Adam Gandelman (GitHub ec2-resource-agents/elasticip)
# All Rights Reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# Further, this software is distributed without any warranty that it is
# free of the rightful claim of any third person regarding infringement
# or the like.  Any license provided herein, whether implied or
# otherwise, applies only to this software file.  Patent licenses, if
# any, provided herein do not apply to combinations of this program with
# other software, or any other product whatsoever.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
#


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

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

# Defaults
OCF_RESKEY_awscli_default="/usr/bin/aws"
OCF_RESKEY_profile_default="default"
OCF_RESKEY_region_default=""
OCF_RESKEY_ip_default=""
OCF_RESKEY_address_default=""
OCF_RESKEY_routing_table_default=""
OCF_RESKEY_routing_table_role_default=""
OCF_RESKEY_interface_default="eth0"
OCF_RESKEY_iflabel_default=""
OCF_RESKEY_monapi_default="false"
OCF_RESKEY_lookup_type_default="InstanceId"

: ${OCF_RESKEY_awscli=${OCF_RESKEY_awscli_default}}
: ${OCF_RESKEY_profile=${OCF_RESKEY_profile_default}}
: ${OCF_RESKEY_region=${OCF_RESKEY_region_default}}
: ${OCF_RESKEY_ip=${OCF_RESKEY_ip_default}}
: ${OCF_RESKEY_address=${OCF_RESKEY_address_default}}
: ${OCF_RESKEY_routing_table=${OCF_RESKEY_routing_table_default}}
: ${OCF_RESKEY_routing_table_role=${OCF_RESKEY_routing_table_role_default}}
: ${OCF_RESKEY_interface=${OCF_RESKEY_interface_default}}
: ${OCF_RESKEY_iflabel=${OCF_RESKEY_iflabel_default}}
: ${OCF_RESKEY_monapi=${OCF_RESKEY_monapi_default}}
: ${OCF_RESKEY_lookup_type=${OCF_RESKEY_lookup_type_default}}

[ -n "$OCF_RESKEY_region" ] && region_opt="--region $OCF_RESKEY_region"
#######################################################################


USAGE="usage: $0 {start|stop|status|meta-data}";
###############################################################################


###############################################################################
#
# Functions
#
###############################################################################


metadata() {
cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="aws-vpc-move-ip" version="2.0">
<version>1.0</version>
<longdesc lang="en">
Resource Agent to move IP addresses within a VPC of the Amazon Webservices EC2
by changing an entry in an specific routing table
</longdesc>
<shortdesc lang="en">Move IP within a VPC of the AWS EC2</shortdesc>

<parameters>
<parameter name="awscli">
<longdesc lang="en">
Path to command line tools for AWS
</longdesc>
<shortdesc lang="en">Path to AWS CLI tools</shortdesc>
<content type="string" default="${OCF_RESKEY_awscli_default}" />
</parameter>

<parameter name="profile">
<longdesc lang="en">
Valid AWS CLI profile name (see ~/.aws/config and 'aws configure')
</longdesc>
<shortdesc lang="en">profile name</shortdesc>
<content type="string" default="${OCF_RESKEY_profile_default}" />
</parameter>

<parameter name="region">
<longdesc lang="en">
Valid AWS region name (e.g., 'us-west-2')
</longdesc>
<shortdesc lang="en">region name</shortdesc>
<content type="string" default="${OCF_RESKEY_region_default}" />
</parameter>

<parameter name="ip" required="1">
<longdesc lang="en">
VPC private IP address
</longdesc>
<shortdesc lang="en">VPC private IP</shortdesc>
<content type="string" default="${OCF_RESKEY_ip_default}" />
</parameter>

<parameter name="address">
<longdesc lang="en">
Deprecated IP address param. Use the ip param instead.
</longdesc>
<shortdesc lang="en">Deprecated VPC private IP Address</shortdesc>
<content type="string" default="${OCF_RESKEY_address_default}" />
</parameter>

<parameter name="routing_table" required="1">
<longdesc lang="en">
Name of the routing table(s), where the route for the IP address should be changed. If declaring multiple routing tables they should be separated by comma. Example: rtb-XXXXXXXX,rtb-YYYYYYYYY
</longdesc>
<shortdesc lang="en">routing table name(s)</shortdesc>
<content type="string" default="${OCF_RESKEY_routing_table_default}" />
</parameter>

<parameter name="routing_table_role" required="0">
<longdesc lang="en">
Role to use to query/update the route table
</longdesc>
<shortdesc lang="en">route table query/update role</shortdesc>
<content type="string" default="${OCF_RESKEY_routing_table_role_default}" />
</parameter>

<parameter name="interface" required="1">
<longdesc lang="en">
Name of the network interface, i.e. eth0
</longdesc>
<shortdesc lang="en">network interface name</shortdesc>
<content type="string" default="${OCF_RESKEY_interface_default}" />
</parameter>

<parameter name="iflabel">
<longdesc lang="en">
You can specify an additional label for your IP address here.
This label is appended to your interface name.

The kernel allows alphanumeric labels up to a maximum length of 15
characters including the interface name and colon (e.g. eth0:foobar1234)
</longdesc>
<shortdesc lang="en">Interface label</shortdesc>
<content type="string" default="${OCF_RESKEY_iflabel_default}"/>
</parameter>

<parameter name="monapi">
<longdesc lang="en">
Enable enhanced monitoring using AWS API calls to check route table entry
</longdesc>
<shortdesc lang="en">Enhanced Monitoring</shortdesc>
<content type="boolean" default="${OCF_RESKEY_monapi_default}" />
</parameter>

<parameter name="lookup_type" required="0">
<longdesc lang="en">
Name of resource type to lookup in route table.
"InstanceId"         : EC2 instance ID. (default)
"NetworkInterfaceId" : ENI ID. (useful in shared VPC setups).
</longdesc>
<shortdesc lang="en">lookup type for route table resource</shortdesc>
<content type="string" default="${OCF_RESKEY_lookup_type_default}" />
</parameter>

</parameters>

<actions>
<action name="start" timeout="180s" />
<action name="stop" timeout="180s" />
<action name="monitor" depth="0" timeout="30s" interval="60s" />
<action name="validate-all" timeout="5s" />
<action name="meta-data" timeout="5s" />
</actions>
</resource-agent>
END
}


execute_cmd_as_role(){
	cmd=$1
	role=$2
	output="$($OCF_RESKEY_awscli sts assume-role --role-arn $role --role-session-name AWSCLI-RouteTableUpdate --profile $OCF_RESKEY_profile $region_opt --output=text)"
	export AWS_ACCESS_KEY_ID="$(echo $output | awk -F" " '$4=="CREDENTIALS" {print $5}')"
	export AWS_SECRET_ACCESS_KEY="$(echo $output | awk -F" " '$4=="CREDENTIALS" {print $7}')"
	export AWS_SESSION_TOKEN="$(echo $output | awk -F" " '$4=="CREDENTIALS" {print $8}')"

	#Execute command
	ocf_log debug "Assumed Role ${role}"
	ocf_log debug "$($OCF_RESKEY_awscli sts get-caller-identity)"
	ocf_log debug "executing command: $cmd"
	response="$($cmd)"
	unset output AWS_ACCESS_KEY_ID AWS_SECRET_ACCESS_KEY AWS_SESSION_TOKEN
	echo $response
}

ec2ip_set_address_param_compat(){
	# Include backward compatibility for the deprecated address parameter
	if [ -z "$OCF_RESKEY_ip" ] && [ -n "$OCF_RESKEY_address" ]; then
		OCF_RESKEY_ip="$OCF_RESKEY_address"
	fi
}

ec2ip_validate() {
	for cmd in $OCF_RESKEY_awscli ip curl; do
		check_binary "$cmd"
	done

	if [ -z "$OCF_RESKEY_profile" ]; then
		ocf_exit_reason "profile parameter not set"
		return $OCF_ERR_CONFIGURED
	fi

	if [ -n "$OCF_RESKEY_iflabel" ]; then
		label=${OCF_RESKEY_interface}:${OFC_RESKEY_iflabel}
		if [ ${#label} -gt 15 ]; then
			ocf_exit_reason "Interface label [$label] exceeds maximum character limit of 15"
			exit $OCF_ERR_CONFIGURED
		fi
	fi

	TOKEN=$(curl -sX PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600")
	EC2_INSTANCE_ID=$(curl -s http://169.254.169.254/latest/meta-data/instance-id -H "X-aws-ec2-metadata-token: $TOKEN")

	if [ -z "${EC2_INSTANCE_ID}" ]; then
		ocf_exit_reason "Instance ID not found. Is this a EC2 instance?"
		return $OCF_ERR_GENERIC
	fi

	return $OCF_SUCCESS
}

ec2ip_monitor() {
	MON_RES=""
	if [ "${OCF_RESKEY_lookup_type}" = "NetworkInterfaceId" ]; then
		EC2_ID="$(ec2ip_get_instance_eni)"
		RESOURCE_TYPE="interface"
	else
		EC2_ID="$EC2_INSTANCE_ID"
		RESOURCE_TYPE="instance"
	fi

	if ocf_is_true ${OCF_RESKEY_monapi} || [ "$__OCF_ACTION" = "start" ] || ocf_is_probe; then
		for rtb in $(echo $OCF_RESKEY_routing_table | sed -e 's/,/ /g'); do
			ocf_log info "monitor: check routing table (API call) - $rtb"
			if [ -z "${OCF_RESKEY_routing_table_role}" ]; then
				cmd="$OCF_RESKEY_awscli --profile $OCF_RESKEY_profile $region_opt --output text ec2 describe-route-tables --route-table-ids $rtb --query RouteTables[*].Routes[?DestinationCidrBlock=='$OCF_RESKEY_ip/32'].$OCF_RESKEY_lookup_type"
				ocf_log debug "executing command: $cmd"
				ROUTE_TO_INSTANCE="$($cmd)"
			else
				cmd="$OCF_RESKEY_awscli $region_opt --output text ec2 describe-route-tables --route-table-ids $rtb --query RouteTables[*].Routes[?DestinationCidrBlock=='$OCF_RESKEY_ip/32'].$OCF_RESKEY_lookup_type"
				ROUTE_TO_INSTANCE="$(execute_cmd_as_role "$cmd" $OCF_RESKEY_routing_table_role)"
			fi
			ocf_log debug "Overlay IP is currently routed to ${ROUTE_TO_INSTANCE}"
			if [ -z "$ROUTE_TO_INSTANCE" ]; then
				ROUTE_TO_INSTANCE="<unknown>"
			fi

			if [ "$EC2_ID" != "$ROUTE_TO_INSTANCE" ]; then
				ocf_log warn "not routed to this $RESOURCE_TYPE ($EC2_ID) but to $RESOURCE_TYPE $ROUTE_TO_INSTANCE on $rtb"
				MON_RES="$MON_RES $rtb"
			fi
			sleep 1
		done

		if [ ! -z "$MON_RES" ]; then
			return $OCF_NOT_RUNNING
		fi

	else
		ocf_log debug "monitor: Enhanced Monitoring disabled - omitting API call"
	fi

	cmd="ip addr show to $OCF_RESKEY_ip up"
	ocf_log debug "executing command: $cmd"
	RESULT=$($cmd | grep "$OCF_RESKEY_ip")
	if [ -z "$RESULT" ]; then
		if [ "$__OCF_ACTION" = "monitor" ] && ! ocf_is_probe; then
			level="error"
		else
			level="info"
		fi

		ocf_log "$level" "IP $OCF_RESKEY_ip not assigned to running interface"
		return $OCF_NOT_RUNNING
	fi

	ocf_log debug "route in VPC and address assigned"
	return $OCF_SUCCESS
}


ec2ip_drop() {
	cmd="ip addr delete ${OCF_RESKEY_ip}/32 dev $OCF_RESKEY_interface"
	ocf_log debug "executing command: $cmd"
	output=$($cmd 2>&1)
	rc=$?

	if [ "$rc" -gt 0 ]; then
		if [ "$__OCF_ACTION" = "start" ]; then
			# expected to fail during start
			level="debug"
		else
			level="warn"
		fi

		ocf_log "$level" "command failed, rc $rc"
		ocf_log "$level" "output/error: $output"
		return $OCF_ERR_GENERIC
	else
		ocf_log debug "output/error: $output"
	fi

	# delete remaining route-entries if any
	ip route show to exact ${OCF_RESKEY_ip}/32 dev $OCF_RESKEY_interface | xargs -r ip route delete
	ip route show table local to exact ${OCF_RESKEY_ip}/32 dev $OCF_RESKEY_interface | xargs -r ip route delete

	return $OCF_SUCCESS
}

ec2ip_get_instance_eni() {
	MAC_FILE="/sys/class/net/${OCF_RESKEY_interface}/address"
	if [ -f $MAC_FILE ]; then
		cmd="cat ${MAC_FILE}"
	else
		cmd="ip -br link show dev ${OCF_RESKEY_interface} | tr -s ' ' | cut -d' ' -f3"
	fi
	ocf_log debug "executing command: $cmd"
	MAC_ADDR="$(eval $cmd)"
	rc=$?
	if [ $rc != 0 ]; then
		ocf_log warn "command failed, rc: $rc"
		return $OCF_ERR_GENERIC
	fi
	ocf_log debug "MAC address associated with interface ${OCF_RESKEY_interface}: ${MAC_ADDR}"

	cmd="curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/${MAC_ADDR}/interface-id -H \"X-aws-ec2-metadata-token: $TOKEN\""
	ocf_log debug "executing command: $cmd"
	EC2_NETWORK_INTERFACE_ID="$(eval $cmd)"
	rc=$?
	if [ $rc != 0 ]; then
		ocf_log warn "command failed, rc: $rc"
		return $OCF_ERR_GENERIC
	fi
	ocf_log debug "network interface id associated MAC address ${MAC_ADDR}: ${EC2_NETWORK_INTERFACE_ID}"
	echo $EC2_NETWORK_INTERFACE_ID
}

ec2ip_get_and_configure() {
	EC2_NETWORK_INTERFACE_ID="$(ec2ip_get_instance_eni)"
	for rtb in $(echo $OCF_RESKEY_routing_table | sed -e 's/,/ /g'); do
		if [ -z "${OCF_RESKEY_routing_table_role}" ]; then
			cmd="$OCF_RESKEY_awscli --profile $OCF_RESKEY_profile $region_opt --output text ec2 replace-route --route-table-id $rtb --destination-cidr-block ${OCF_RESKEY_ip}/32 --network-interface-id $EC2_NETWORK_INTERFACE_ID"
			ocf_log debug "executing command: $cmd"
			$cmd
		else
			cmd="$OCF_RESKEY_awscli $region_opt --output text ec2 replace-route --route-table-id $rtb --destination-cidr-block ${OCF_RESKEY_ip}/32 --network-interface-id $EC2_NETWORK_INTERFACE_ID"
			update_response="$(execute_cmd_as_role "$cmd" $OCF_RESKEY_routing_table_role)"
		fi
		rc=$?
		if [ "$rc" != 0 ]; then
			ocf_log warn "command failed, rc: $rc"
			return $OCF_ERR_GENERIC
		fi
		sleep 1
	done

	# Reconfigure the local ip address
	ec2ip_drop

	extra_opts=""
	if [ -n "$OCF_RESKEY_iflabel" ]; then
		extra_opts="$extra_opts label $OCF_RESKEY_interface:$OCF_RESKEY_iflabel"
	fi

	cmd="ip addr add ${OCF_RESKEY_ip}/32 dev $OCF_RESKEY_interface $extra_opts"
	ocf_log debug "executing command: $cmd"
	$cmd
	rc=$?
	if [ $rc != 0 ]; then
		ocf_log warn "command failed, rc: $rc"
		return $OCF_ERR_GENERIC
	fi

	return $OCF_SUCCESS
}

ec2ip_stop() {
	ocf_log info "EC2: Bringing down IP address $OCF_RESKEY_ip"

	ec2ip_monitor
	if [ $? = $OCF_NOT_RUNNING ]; then
		ocf_log info "EC2: Address $OCF_RESKEY_ip already down"
		return $OCF_SUCCESS
	fi

	ec2ip_drop
	if [ $? != $OCF_SUCCESS ]; then
		return $OCF_ERR_GENERIC
	fi

	ec2ip_monitor
	if [ $? != $OCF_NOT_RUNNING ]; then
		ocf_log error "EC2: Couldn't bring down IP address $OCF_RESKEY_ip on interface $OCF_RESKEY_interface."
		return $OCF_ERR_GENERIC
	fi

	ocf_log info "EC2: Successfully brought down $OCF_RESKEY_ip"
	return $OCF_SUCCESS
}

ec2ip_start() {
	ocf_log info "EC2: Moving IP address $OCF_RESKEY_ip to this host by adjusting routing table $OCF_RESKEY_routing_table"

	ec2ip_monitor
	if [ $? = $OCF_SUCCESS ]; then
		ocf_log info "EC2: $OCF_RESKEY_ip already started"
		return $OCF_SUCCESS
	fi

	ocf_log info "EC2: Adjusting routing table and locally configuring IP address"
	ec2ip_get_and_configure
	rc=$?
	if [ $rc != $OCF_SUCCESS ]; then
		ocf_log error "Received $rc from 'aws'"
		return $OCF_ERR_GENERIC
	fi

	ec2ip_monitor
	if [ $? != $OCF_SUCCESS ]; then
		ocf_log error "EC2: IP address couldn't be configured on this host (IP: $OCF_RESKEY_ip, Interface: $OCF_RESKEY_interface)"
		return $OCF_ERR_GENERIC
	fi

	return $OCF_SUCCESS
}

###############################################################################
#
# MAIN
#
###############################################################################

case $__OCF_ACTION in
	meta-data)
		metadata
		exit $OCF_SUCCESS
		;;
	usage|help)
		echo $USAGE
		exit $OCF_SUCCESS
		;;
esac

if ! ocf_is_root; then
	ocf_log err "You must be root for $__OCF_ACTION operation."
	exit $OCF_ERR_PERM
fi

ec2ip_set_address_param_compat

ec2ip_validate

case $__OCF_ACTION in
	start)
		ec2ip_start;;
	stop)
		ec2ip_stop;;
	monitor)
		ec2ip_monitor;;
	validate-all)
		exit $?;;
	*)
		echo $USAGE
		exit $OCF_ERR_UNIMPLEMENTED
		;;
esac