#!/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.)
#  - 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_profile_default="default"
OCF_RESKEY_api_delay_default="3"

: ${OCF_RESKEY_awscli=${OCF_RESKEY_awscli_default}}
: ${OCF_RESKEY_profile=${OCF_RESKEY_profile_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".

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="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="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 --profile $OCF_RESKEY_profile ec2 associate-address  \
            --network-interface-id ${NETWORK_ID} \
            --allocation-id ${ALLOCATION_ID} \
            --private-ip-address ${PRIVATE_IP_ADDRESS}
        RET=$?
    else
        $AWSCLI --profile $OCF_RESKEY_profile 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 --profile $OCF_RESKEY_profile --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 --profile ${OCF_RESKEY_profile} \
        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 --profile $OCF_RESKEY_profile ec2 describe-instances --instance-id "${INSTANCE_ID}" | grep -q "${ELASTIC_IP}"
    RET=$?

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

awseip_validate() {
    check_binary ${AWSCLI}

    if [ -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
        ;;
esac 

AWSCLI="${OCF_RESKEY_awscli}"
ELASTIC_IP="${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
        ;;
    usage|help)
        awseip_usage
        exit $OCF_SUCCESS
        ;;
    *)
        awseip_usage
        exit $OCF_ERR_UNIMPLEMENTED
        ;;
esac

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