#!/bin/bash
# ---------------------------------------------------------------------
# Copyright 2016 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ---------------------------------------------------------------------
# Description:  Google Cloud Platform - Floating IP Address (Alias)
# Version:      1.0.45
# Date:         08/October/2019
# ---------------------------------------------------------------------

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

meta_data() {
	cat <<EOF
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="gcp:alias">
  <version>1.0</version>
  <longdesc lang="en">Floating IP Address on Google Cloud Platform - Using Alias IP address functionality to attach a secondary IP address to a running instance</longdesc>
  <shortdesc lang="en">Floating IP Address on Google Cloud Platform</shortdesc>
  <parameters>
    <parameter name="hostlist" unique="1" required="1">
      <longdesc lang="en">List of hosts in the cluster</longdesc>
      <shortdesc lang="en">Host list</shortdesc>
      <content type="string" default="" />
    </parameter>
    <parameter name="logging" unique="0" required="0">
      <longdesc lang="en">If enabled (set to true), IP failover logs will be posted to stackdriver logging</longdesc>
      <shortdesc lang="en">Stackdriver-logging support</shortdesc>
      <content type="boolean" default="" />
    </parameter>
    <parameter name="alias_ip" unique="1" required="1">
      <longdesc lang="en">IP Address to be added including CIDR. E.g 192.168.0.1/32</longdesc>
      <shortdesc lang="en">IP Address to be added including CIDR. E.g 192.168.0.1/32</shortdesc>
      <content type="string" default="" />
    </parameter>
    <parameter name="alias_range_name" unique="1" required="0">
      <longdesc lang="en">Subnet name for the Alias IP2</longdesc>
      <shortdesc lang="en">Subnet name for the Alias IP</shortdesc>
      <content type="string" default="" />
    </parameter>
    <parameter name="gcloud_path" unique="0" required="0">
      <longdesc lang="en">Full path of the gcloud binary. E.g /usr/local/gsdk/google-cloud-sdk/bin/gcloud - If this is left blank, the default path of /usr/bin/gcloud will be used</longdesc>
      <shortdesc lang="en">Full path of the gcloud binary. E.g /usr/local/gsdk/google-cloud-sdk/bin/gcloud</shortdesc>
      <content type="string" default="" />
    </parameter>
  </parameters>
  <actions>
    <action name="start" timeout="300" />
    <action name="stop" timeout="15" />
    <action name="monitor" timeout="15" interval="60" depth="0" />
    <action name="meta-data" timeout="15" />
  </actions>
</resource-agent>
EOF
}

get_zone() {
	ZONE=$(${GCLOUDCMD} --quiet compute instances list --filter="name=('${1}')" --format 'csv[no-heading](zone)')
}

get_ip() {
	IP=$(${GCLOUDCMD} --quiet compute instances describe "${1}" --zone "${ZONE}" --format text | grep aliasIpRanges | grep "${OCF_RESKEY_alias_ip}" | awk '{ print $2 }')
}

get_my_zone() {
	# execute fetch of zone
	MYZONE=$(curl -fsH'Metadata-Flavor: Google' "http://metadata.google.internal/computeMetadata/v1/instance/zone")

	# if return code isn't 0, keep trying
	while [[ "$?" -ne 0 ]]; do
		echo "Unable to obtain zone from metadata server. Trying again in 5 seconds"
		sleep 5
		MYZONE=$(curl -fsH'Metadata-Flavor: Google' "http://metadata.google.internal/computeMetadata/v1/instance/zone")
	done

	# remove zone prefix
	MYZONE=$(echo "$MYZONE" | cut -d'/' -f4)
}

get_my_ip() {
	# execute fetch of zone
	if [[ $(curl -sH'Metadata-Flavor: Google' "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip-aliases/") ]]; then
		MYIP=$(curl -sH'Metadata-Flavor: Google' "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip-aliases/0")
	fi

	# if return code isn't 0, keep trying
	while [[ "$?" -ne 0 ]]; do
		if [[ $(curl -sH'Metadata-Flavor: Google' "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip-aliases/") ]]; then
			echo "Unable to obtain Alias IP from metadata server. Trying again in 5 seconds"
			sleep 5
			MYIP=$(curl -fsH'Metadata-Flavor: Google' "http://metadata.google.internal/computeMetadata/v1/instance/network-interfaces/0/ip-aliases/0")
		else
			unset MYIP
			break
		fi
	done
}

get_gcloud() {
	## if gcloud command isn't set, default to the default path
	if [[ -n "${OCF_RESKEY_gcloud_path}" ]]; then
		GCLOUDCMD="${OCF_RESKEY_gcloud_path}"
	else
		GCLOUDCMD="/usr/bin/gcloud"
	fi

	## check gcloud command exists
	if [[ ! -f "${GCLOUDCMD}" ]]; then
		log_error "gcloud command not found at ${GCLOUDCMD}"
		exit 1
	fi
}

check_gcloud_version() {
	${GCLOUDCMD} --quiet beta compute instances network-interfaces --help >/dev/null
	if [[ "$?" -gt 0 ]]; then
		log_error "gcloud version does not support beta 'network-interfaces' function. Upgrade gcloud SDK or specifiy gcloud path to a newer version"
		exit 1
	fi
}

log_info() {
	echo "gcp:alias - INFO - ${1}"
	LOG="$(hostname) ${OCF_RESOURCE_INSTANCE} \"${1}\""
	logger -t gcp:alias "INFO - ${1}"
	if [[ -n "${OCF_RESKEY_logging}" ]]; then
		if [[ "${OCF_RESKEY_logging,,}" =~ ^(yes|true|enabled)$ ]]; then
			timeout 30 ${GCLOUDCMD} logging write "${HOSTNAME}" "${LOG}" --severity=INFO || :
		fi
	fi
}

log_error() {
	echo "gcp:alias - ERROR - ${1}"
	LOG="$(hostname) ${OCF_RESOURCE_INSTANCE} \"${1}\""
	logger -t gcp:alias "ERROR - ${1}"
	if [[ -n "${OCF_RESKEY_logging}" ]]; then
		if [[ "${OCF_RESKEY_logging,,}" =~ ^(yes|true|enabled)$ ]]; then
			timeout 30 ${GCLOUDCMD} logging write "${HOSTNAME}" "${LOG}" --severity=ERROR || :
		fi
	fi
}

case ${1} in

	start)
		get_gcloud
		check_gcloud_version
		get_my_zone
		get_my_ip

		## If I already have the IP, exit. If it has an alias IP that isn't the VIP, then remove it
		if [[ -n "${MYIP}" ]]; then
			if [[ "${MYIP}" == "${OCF_RESKEY_alias_ip}" ]]; then
				log_info "${HOSTNAME} already has ${MYIP} attached. No action required."
				exit 0
			else
				log_info "Removing ${MYIP} from ${HOSTNAME}"
				${GCLOUDCMD} --quiet beta compute instances network-interfaces update "${HOSTNAME}" --zone "${MYZONE}" --aliases ""
			fi
		fi

		## Loops through all hosts & remove the alias IP from the host that has it
		HOSTLIST=${OCF_RESKEY_hostlist/$HOSTNAME/}
		IFS=' ' read -r -a HOSTS <<<"$HOSTLIST"
		IP="TBD"
		for HOST in "${HOSTS[@]}"; do
			get_zone "${HOST}"
			get_ip "${HOST}"
			log_info "Checking to see if ${HOST} owns $OCF_RESKEY_alias_ip"
			## keep trying to remove until it's not there anymore - Added due to the fingerprint bug
			while [[ -n ${IP} ]]; do
				log_info "${IP} is attached to ${HOST} - Removing all alias IP addresses from ${HOST}"
				${GCLOUDCMD} --quiet beta compute instances network-interfaces update "${HOST}" --zone "${ZONE}" --aliases ""
				get_ip "${HOST}"
				sleep 2
			done
		done

		## add alias IP to localhost
		if [[ -z "${OCF_RESKEY_alias_range_name}" ]]; then
			log_info "Adding ${OCF_RESKEY_alias_ip} to ${HOSTNAME}"
			${GCLOUDCMD} --quiet beta compute instances network-interfaces update "${HOSTNAME}" --zone "${MYZONE}" --aliases "${OCF_RESKEY_alias_ip}"
		else
			log_info "Adding ${OCF_RESKEY_alias_ip} in secondary range ${OCF_RESKEY_alias_range_name} to ${HOSTNAME}"
			${GCLOUDCMD} --quiet beta compute instances network-interfaces update "${HOSTNAME}" --zone "${MYZONE}" --aliases "${OCF_RESKEY_alias_range_name}:${OCF_RESKEY_alias_ip}"
		fi

		## Check the IP has been added
		get_my_ip
		if [[ -n "${MYIP}" ]]; then
			if [[ "${MYIP}" == "${OCF_RESKEY_alias_ip}" ]]; then
				log_info "Finished adding ${OCF_RESKEY_alias_ip} to ${HOSTNAME}"
			else
				log_error "Failed to add IP. ${HOSTNAME} has an IP attached but it isn't ${OCF_RESKEY_alias_ip}"
				exit 1
			fi
		else
			log_error "Failed to add IP address ${OCF_RESKEY_alias_ip} to ${HOSTNAME}"
			exit 1
		fi

		#exit gracefully
		exit 0
		;;

	stop)
		#exit gracefully
		exit 0
		;;

	status|monitor)
		get_gcloud
		get_my_ip
		if [[ -n ${MYIP} ]]; then
			if [[ "${MYIP}" == "${OCF_RESKEY_alias_ip}" ]]; then
				log_info "${HOSTNAME} has the correct IP address attached"
				exit 0
			else
				exit 7
			fi
		else
			exit 7
		fi
		;;

	meta-data)
		meta_data
		;;

	*)
		echo "gcp:alias - no such function \"${1}\""
		exit 1
		;;
esac