#!/bin/sh
#
#
#    Manage Elastic IP with Pacemaker
#
#
# Copyright 2016-2018 guessi <guessi@gmail.com>
#
# 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.
#
#

#
#  Prerequisites:
#
#  - preconfigured AWS CLI running environment (AccessKey, SecretAccessKey, etc.) or
#    (AWSRole) Setup up relevant AWS Policies to allow agent related functions to be executed.
#  - a reserved secondary private IP address for EC2 instances high availability
#  - IAM user role with the following permissions:
#    * DescribeInstances
#    * AssociateAddress
#    * DescribeAddresses
#    * DisassociateAddress
#

#######################################################################
# 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_api_delay_default="3"

: ${OCF_RESKEY_awscli=${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}}
: ${OCF_RESKEY_api_delay=${OCF_RESKEY_api_delay_default}}

meta_data() {
    cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="awseip" version="1.0">
<version>1.0</version>

<longdesc lang="en">
Resource Agent for Amazon AWS Elastic IP Addresses.

It manages AWS Elastic IP Addresses with awscli.

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">Amazon AWS Elastic IP Address Resource Agent</shortdesc>

<parameters>

<parameter name="awscli" unique="0">
<longdesc lang="en">
command line tools for aws services
</longdesc>
<shortdesc lang="en">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="elastic_ip" unique="1" required="1">
<longdesc lang="en">
reserved elastic ip for ec2 instance
</longdesc>
<shortdesc lang="en">reserved elastic ip for ec2 instance</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="allocation_id" unique="1" required="1">
<longdesc lang="en">
reserved allocation id for ec2 instance
</longdesc>
<shortdesc lang="en">reserved allocation id for ec2 instance</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="private_ip_address" unique="1" required="0">
<longdesc lang="en">
predefined private ip address for ec2 instance
</longdesc>
<shortdesc lang="en">predefined private ip address for ec2 instance</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="region" required="0">
<longdesc lang="en">
Region for AWS resource (required for role-based authentication)
</longdesc>
<shortdesc lang="en">Region</shortdesc>
<content type="string" default="${OCF_RESKEY_region_default}" />
</parameter>

<parameter name="api_delay" unique="0">
<longdesc lang="en">
a short delay between API calls, to avoid sending API too quick
</longdesc>
<shortdesc lang="en">a short delay between API calls</shortdesc>
<content type="integer" default="${OCF_RESKEY_api_delay_default}" />
</parameter>

</parameters>

<actions>
<action name="start"        timeout="30s" />
<action name="stop"         timeout="30s" />
<action name="monitor"      timeout="30s" interval="20s" depth="0" />
<action name="migrate_to"   timeout="30s" />
<action name="migrate_from" timeout="30s" />
<action name="meta-data"    timeout="5s" />
<action name="validate"     timeout="10s" />
<action name="validate-all" timeout="10s" />
</actions>
</resource-agent>
END
}

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

awseip_usage() {
    cat <<END
usage: $0 {start|stop|monitor|migrate_to|migrate_from|validate|validate-all|meta-data}

Expects to have a fully populated OCF RA-compliant environment set.
END
}

awseip_start() {
    awseip_monitor && return $OCF_SUCCESS

    if [ -n "${PRIVATE_IP_ADDRESS}" ]; then
        NETWORK_INTERFACES_MACS=$(curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/ -H "X-aws-ec2-metadata-token: $TOKEN")
        for MAC in ${NETWORK_INTERFACES_MACS}; do
            curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/${MAC}/local-ipv4s -H "X-aws-ec2-metadata-token: $TOKEN" |
                grep -q "^${PRIVATE_IP_ADDRESS}$"
            if [ $? -eq 0 ]; then
                NETWORK_ID=$(curl -s http://169.254.169.254/latest/meta-data/network/interfaces/macs/${MAC}/interface-id -H "X-aws-ec2-metadata-token: $TOKEN")
            fi
        done
        $AWSCLI_CMD ec2 associate-address  \
            --network-interface-id ${NETWORK_ID} \
            --allocation-id ${ALLOCATION_ID} \
            --private-ip-address ${PRIVATE_IP_ADDRESS}
        RET=$?
    else
        $AWSCLI_CMD ec2 associate-address  \
            --instance-id ${INSTANCE_ID} \
            --allocation-id ${ALLOCATION_ID}
        RET=$?
    fi

    # delay to avoid sending request too fast
    sleep ${OCF_RESKEY_api_delay}

    if [ $RET -ne 0 ]; then
        return $OCF_NOT_RUNNING
    fi

    ocf_log info "elastic_ip has been successfully brought up (${ELASTIC_IP})"
    return $OCF_SUCCESS
}

awseip_stop() {
    awseip_monitor || return $OCF_SUCCESS

    ASSOCIATION_ID=$($AWSCLI_CMD --output json ec2 describe-addresses \
                         --allocation-id ${ALLOCATION_ID} | grep -m 1 "AssociationId" | awk -F'"' '{print$4}')

    if [ -z "${ASSOCIATION_ID}" ]; then
        ocf_log info "ASSOCIATION_ID not found while stopping AWS Elastic IP"
        return $OCF_NOT_RUNNING
    fi

    $AWSCLI_CMD ec2 disassociate-address --association-id ${ASSOCIATION_ID}
    RET=$?

    # delay to avoid sending request too fast
    sleep ${OCF_RESKEY_api_delay}

    if [ $RET -ne 0 ]; then
        return $OCF_NOT_RUNNING
    fi

    ocf_log info "elastic_ip has been successfully brought down (${ELASTIC_IP})"
    return $OCF_SUCCESS
}

awseip_monitor() {
    $AWSCLI_CMD ec2 describe-instances --instance-id "${INSTANCE_ID}" | grep -q "${ELASTIC_IP}"
    RET=$?

    if [ $RET -ne 0 ]; then
        return $OCF_NOT_RUNNING
    fi
    return $OCF_SUCCESS
}

awseip_validate() {
    check_binary "${OCF_RESKEY_awscli}"

    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 [ -z "${INSTANCE_ID}" ]; then
        ocf_exit_reason "instance_id not found. Is this a EC2 instance?"
        return $OCF_ERR_GENERIC
    fi

    return $OCF_SUCCESS
}

case $__OCF_ACTION in
    meta-data)
        meta_data
        exit $OCF_SUCCESS
        ;;
    usage|help)
        awseip_usage
        exit $OCF_SUCCESS
        ;;
esac

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 ${OCF_RESKEY_region}"
fi
ELASTIC_IP="${OCF_RESKEY_elastic_ip}"
ALLOCATION_ID="${OCF_RESKEY_allocation_id}"
PRIVATE_IP_ADDRESS="${OCF_RESKEY_private_ip_address}"
TOKEN=$(curl -sX PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600")
INSTANCE_ID=$(curl -s http://169.254.169.254/latest/meta-data/instance-id -H "X-aws-ec2-metadata-token: $TOKEN")

case $__OCF_ACTION in
    start)
        awseip_validate
        awseip_start
        ;;
    stop)
        awseip_stop
        ;;
    monitor)
        awseip_monitor
        ;;
    migrate_to)
        ocf_log info "Migrating ${OCF_RESOURCE_INSTANCE} to ${OCF_RESKEY_CRM_meta_migrate_target}."
        awseip_stop
        ;;
    migrate_from)
        ocf_log info "Migrating ${OCF_RESOURCE_INSTANCE} from ${OCF_RESKEY_CRM_meta_migrate_source}."
        awseip_start
        ;;
    reload)
        ocf_log info "Reloading ${OCF_RESOURCE_INSTANCE} ..."
        ;;
    validate|validate-all)
        awseip_validate
        ;;
    *)
        awseip_usage
        exit $OCF_ERR_UNIMPLEMENTED
        ;;
esac

rc=$?
ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION : $rc"
exit $rc