#!/bin/bash
#
#
# NovaCompute agent manages compute daemons.
#
# Copyright (c) 2015
#
# 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
###

: ${__OCF_ACTION=$1}

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

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

<longdesc lang="en">
Facility for tacking a list of compute nodes and reliably evacuating the ones that fence_evacuate has flagged.
</longdesc>
<shortdesc lang="en">Evacuator for OpenStack Nova Compute Server</shortdesc>

<parameters>

<parameter name="auth_url" unique="0" required="1">
<longdesc lang="en">
Authorization URL for connecting to keystone in admin context
</longdesc>
<shortdesc lang="en">Authorization URL</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="username" unique="0" required="1">
<longdesc lang="en">
Username for connecting to keystone in admin context
</longdesc>
<shortdesc lang="en">Username</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="password" unique="0" required="1">
<longdesc lang="en">
Password for connecting to keystone in admin context
</longdesc>
<shortdesc lang="en">Password</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="tenant_name" unique="0" required="1">
<longdesc lang="en">
Tenant name for connecting to keystone in admin context.
Note that with Keystone V3 tenant names are only unique within a domain.
</longdesc>
<shortdesc lang="en">Tenant name</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="domain" unique="0" required="0">
<longdesc lang="en">
DNS domain in which hosts live, useful when the cluster uses short names and nova uses FQDN
</longdesc>
<shortdesc lang="en">DNS domain</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="endpoint_type" unique="0" required="0">
<longdesc lang="en">
Nova API location (internal, public or admin URL)
</longdesc>
<shortdesc lang="en">Nova API location (internal, public or admin URL)</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="region_name" unique="0" required="0">
<longdesc lang="en">
Region name for connecting to nova.
</longdesc>
<shortdesc lang="en">Region name</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="insecure" unique="0" required="0">
<longdesc lang="en">
Explicitly allow client to perform "insecure" TLS (https) requests.
The server's certificate will not be verified against any certificate authorities.
This option should be used with caution.
</longdesc>
<shortdesc lang="en">Allow insecure TLS requests</shortdesc>
<content type="boolean" default="0" />
</parameter>

<parameter name="no_shared_storage" unique="0" required="0">
<longdesc lang="en">
Disable shared storage recovery for instances. Use at your own risk!
</longdesc>
<shortdesc lang="en">Disable shared storage recovery for instances</shortdesc>
<content type="boolean" default="0" />
</parameter>

</parameters>

<actions>
<action name="start"        timeout="20" />
<action name="stop"         timeout="20" />
<action name="monitor"      timeout="600" interval="10" depth="0"/>
<action name="validate-all" timeout="20" />
<action name="meta-data"    timeout="5" />
</actions>
</resource-agent>
END
}

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

# don't exit on TERM, to test that lrmd makes sure that we do exit
trap sigterm_handler TERM
sigterm_handler() {
    ocf_log info "They use TERM to bring us down. No such luck."
    return
}

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

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

evacuate_stop() {
    rm -f "$statefile"
    return $OCF_SUCCESS
}

evacuate_start() {
    touch "$statefile"
    # Do not invole monitor here so that the start timeout can be low
    return $?
}

update_evacuation() {
    attrd_updater -p -n evacuate -Q -N ${1} -U ${2}
    arc=$?
    if [ ${arc} != 0 ]; then
        ocf_log warn "Can not set evacuation state of ${1} to ${2}: ${arc}"
    fi
    return ${arc}
}

handle_evacuations() {
    while [ $# -gt 0 ]; do
        node=$1
        state=$2
        shift; shift;
        need_evacuate=0

        case $state in
            "")
                ;;
            no)
                ocf_log debug "$node is either fine or already handled"
                ;;
            yes) need_evacuate=1
                ;;
            *@*)
                where=$(echo $state | awk -F@ '{print $1}')
                when=$(echo $state | awk -F@ '{print $2}')
                now=$(date +%s)

                if [ $(($now - $when)) -gt 60 ]; then
                    ocf_log info "Processing partial evacuation of $node by" \
                        "$where at $when"
                    need_evacuate=1
                else
                    # Give some time for any in-flight evacuations to either
                    # complete or fail Nova won't react well if there are two
                    # overlapping requests
                    ocf_log info "Deferring processing partial evacuation of" \
                        "$node by $where at $when"
                fi
                ;;
        esac

        if [ $need_evacuate = 1 ]; then
            found=0
            ocf_log notice "Initiating evacuation of $node"

            for known in $(fence_compute ${fence_options} -o list | \
                tr -d ','); do
                if [ ${known} = ${node} ]; then
                    found=1
                    break
                fi
            done

            if [ $found = 0 ]; then
                ocf_log info "Nova does not know about ${node}"
                # Dont mark as no because perhaps nova is unavailable right now
                continue
            fi

            update_evacuation ${node} "$(uname -n)@$(date +%s)"
            if [ $? != 0 ]; then
                return $OCF_SUCCESS
            fi

            fence_compute ${fence_options} -o off -n $node
            rc=$?

            if [ $rc = 0 ]; then
                update_evacuation ${node} no
                ocf_log notice "Completed evacuation of $node"
            else
                ocf_log warn "Evacuation of $node failed: $rc"
                update_evacuation ${node} yes
            fi
        fi
    done

    return $OCF_SUCCESS
}

evacuate_monitor() {
    if [ ! -f "$statefile" ]; then
        return $OCF_NOT_RUNNING
    fi

    handle_evacuations $(
        attrd_updater -n evacuate -A \
            2> >(grep -v "attribute does not exist" 1>&2) |
            sed 's/ value=""/ value="no"/' |
            tr '="' '  ' |
            awk '{print $4" "$6}'
    )
    return $OCF_SUCCESS
}

evacuate_validate() {
    rc=$OCF_SUCCESS
    fence_options=""

    check_binary fence_compute

    # Is the state directory writable?
    state_dir=$(dirname $statefile)
    touch "$state_dir/$$"
    if [ $? != 0 ]; then
        ocf_exit_reason "Invalid state directory: $state_dir"
        return $OCF_ERR_ARGS
    fi
    rm -f "$state_dir/$$"

    if [ -z "${OCF_RESKEY_auth_url}" ]; then
        ocf_exit_reason "auth_url not configured"
        exit $OCF_ERR_CONFIGURED
    fi

    fence_options="${fence_options} -k ${OCF_RESKEY_auth_url}"

    if [ -z "${OCF_RESKEY_username}" ]; then
        ocf_exit_reason "username not configured"
        exit $OCF_ERR_CONFIGURED
    fi

    fence_options="${fence_options} -l ${OCF_RESKEY_username}"

    if [ -z "${OCF_RESKEY_password}" ]; then
        ocf_exit_reason "password not configured"
        exit $OCF_ERR_CONFIGURED
    fi

    fence_options="${fence_options} -p ${OCF_RESKEY_password}"

    if [ -z "${OCF_RESKEY_tenant_name}" ]; then
        ocf_exit_reason "tenant_name not configured"
        exit $OCF_ERR_CONFIGURED
    fi

    fence_options="${fence_options} -t ${OCF_RESKEY_tenant_name}"

    if [ -n "${OCF_RESKEY_domain}" ]; then
        fence_options="${fence_options} -d ${OCF_RESKEY_domain}"
    fi

    if [ -n "${OCF_RESKEY_region_name}" ]; then
        fence_options="${fence_options} \
            --region-name ${OCF_RESKEY_region_name}"
    fi

    if [ -n "${OCF_RESKEY_insecure}" ]; then
        if ocf_is_true "${OCF_RESKEY_insecure}"; then
            fence_options="${fence_options} --insecure"
        fi
    fi

    if [ -n "${OCF_RESKEY_no_shared_storage}" ]; then
        if ocf_is_true "${OCF_RESKEY_no_shared_storage}"; then
            fence_options="${fence_options} --no-shared-storage"
        fi
    fi

    if [ -n "${OCF_RESKEY_endpoint_type}" ]; then
        case ${OCF_RESKEY_endpoint_type} in
            adminURL|publicURL|internalURL)
                ;;
            *)
                ocf_exit_reason "endpoint_type ${OCF_RESKEY_endpoint_type}" \
                    "not valid. Use adminURL or publicURL or internalURL"
                exit $OCF_ERR_CONFIGURED
                ;;
        esac
        fence_options="${fence_options} -e ${OCF_RESKEY_endpoint_type}"
    fi

    if [ $rc != $OCF_SUCCESS ]; then
        exit $rc
    fi
    return $rc
}

statefile="${HA_RSCTMP}/${OCF_RESOURCE_INSTANCE}.active"

case $__OCF_ACTION in
    start)
        evacuate_validate
        evacuate_start
        ;;
    stop)
        evacuate_stop
        ;;
    monitor)
        evacuate_validate
        evacuate_monitor
        ;;
    meta-data)
        meta_data
        exit $OCF_SUCCESS
        ;;
    usage|help)
        evacuate_usage
        exit $OCF_SUCCESS
        ;;
    validate-all)
        exit $OCF_SUCCESS
        ;;
    *)
        evacuate_usage
        exit $OCF_ERR_UNIMPLEMENTED
        ;;
esac
rc=$?
ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION : $rc"
exit $rc