#!/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_auth_type_default="key"
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}}
: ${OCF_RESKEY_auth_type=${OCF_RESKEY_auth_type_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}}
#######################################################################


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

Credentials needs to be setup by running "aws configure", or by using AWS Policies.

See https://aws.amazon.com/cli/ for more information about awscli.
</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="auth_type">
<longdesc lang="en">
Authentication type "key" for AccessKey and SecretAccessKey set via "aws configure",
or "role" to use AWS Policies.
</longdesc>
<shortdesc lang="en">Authentication type</shortdesc>
<content type="string" default="${OCF_RESKEY_auth_type_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=$2
	output="$($AWSCLI_CMD sts assume-role --role-arn $role --role-session-name AWSCLI-RouteTableUpdate --output=text)"
	export AWS_ACCESS_KEY_ID="$(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 [ "x${OCF_RESKEY_auth_type}" = "xkey" ] && [ -z "$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="$AWSCLI_CMD --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="$AWSCLI_CMD --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

AWSCLI_CMD="${OCF_RESKEY_awscli}"
if [ "x${OCF_RESKEY_auth_type}" = "xkey" ]; then
	AWSCLI_CMD="$AWSCLI_CMD --profile ${OCF_RESKEY_profile}"
elif [ "x${OCF_RESKEY_auth_type}" = "xrole" ]; then
	if [ -z "${OCF_RESKEY_region}" ]; then
		ocf_exit_reason "region needs to be set when using role-based authentication"
		exit $OCF_ERR_CONFIGURED
	fi
else
	ocf_exit_reason "Incorrect auth_type: ${OCF_RESKEY_auth_type}"
	exit $OCF_ERR_CONFIGURED
fi
if [ -n "${OCF_RESKEY_region}" ]; then
	AWSCLI_CMD="$AWSCLI_CMD --region ${OCF_RESKEY_region}"
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