vm-bhyve/lib/vm-migration

#!/bin/sh
#-------------------------------------------------------------------------+
# Copyright (C) 2015 Matt Churchyard (churchers@gmail.com)
# All rights reserved
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted providing that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
# STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
# IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

# vm recv ...
# recieve a guest that is being sent from another host
#
# @param string _name name of the new guest to recieve into
#
migration::recv(){
    local _name="$1"
    local _ds="default"
    local _conf

    [ -z "${_name}" ] && util::usage
    core::check_name "${_name}" || util::err "invalid virtual machine name - '${_name}'"
    datastore::get "${_ds}" || util::err "unable to load datastore - '${_ds}'"
    [ -z "${VM_DS_ZFS}" ] && util::err "${_ds} datastore must be on ZFS to support migration"
    [ -d "${VM_DS_PATH}/${_name}" ] && util::err "directory ${VM_DS_PATH}/${_name} already exists"

    echo "Recieving guest to ${VM_DS_PATH}/${_name}"

    # try to recieve the first snapshot
    echo "  * waiting for initial full snapshot"
    socat TCP-LISTEN:12000 - | zfs recv "${VM_DS_ZFS_DATASET}/${_name}" >/dev/null 2>&1
    [ $? -ne 0 ] && util::err "detected error recieving full snapshot"
    echo "  * first stage completed"

    # wait for changes since first snapshot
    echo "  * waiting for incremental snapshot"
    socat TCP-LISTEN:12001 - | zfs recv "${VM_DS_ZFS_DATASET}/${_name}" >/dev/null 2>&1
    [ $? -ne 0 ] && util::err "detected error recieving incremental snapshot"
    echo "  * second stage completed"

    # try to find the config file
    echo "  * updating configuration file"
    _conf=$(find "${VM_DS_PATH}/${_name}/" -name "*.conf" | awk -F"/" '{print $NF}')
    [ -z "${_conf}" ] && util::err "unable to locate guest configuration file"
    mv "${VM_DS_PATH}/${_name}/${_conf}" "${VM_DS_PATH}/${_name}/${_name}.conf"

    echo "  * attempting to start ${_name}"
    core::__start "${_name}"
}

# vm send ...
# send a guest to another system
#
# @param string _name name of the guest to send
# @param string _host host to send to
#
migration::send(){
    local _name="$1"
    local _host="$2"
    local _snap1 _snap2 _state _running _pid _vm _count=0
    local IFS=$'\n'

    [ -z "${_name}" -o -z "${_host}" ] && util::usage
    datastore::get_guest "${_name}" || util::err "unable to locate guest - '${_name}'"
    [ -z "${VM_DS_ZFS}" ] && util::err "${VM_DS_NAME} datastore must be on ZFS to support migration"

    # check if vm is running
    vm::confirm_stopped "${_name}" "1" >/dev/null 2>&1
    _state="$?"
    [ ${_state} -eq 2 ] && util::err "guest is powered up on another host"
    [ ${_state} -eq 1 ] && _running="1"

    # try to get pid if it is running
    if [ -n "${_running}" ]; then
        vm::running_load

        for _vm in ${VM_RUN_BHYVE}; do
            [ "${_vm##* }" = "${_name}" ] && _pid="${_vm%% *}"
        done

        [ -z "${_pid}" ] && util::err "guest seems to be running but can't find its pid"
    fi

    echo "Sending ${_name} to ${_host}"

    # take first snapshot
    echo "  * taking initial snapshot"
    _snap1="$(date +'%Y%m%d%H%M%S')"
    zfs snapshot -r "${VM_DS_ZFS_DATASET}/${_name}@${_snap1}"

    echo "  * sending full snapshot to remote host"
    zfs send -R "${VM_DS_ZFS_DATASET}/${_name}@${_snap1}" | socat - "TCP4:${_host}:12000"
    echo "  * first stage completed"

    echo "  * giving time for remote socket to close"
    sleep 10

    # if it's running, try and stop it
    if [ -n "${_running}" ]; then
        echo "  * attempting to stop guest locally"
        while [ ${_count} -le 60 ]; do
            kill ${_pid} >/dev/null 2>&1
            sleep 2
            kill -0 ${_pid} >/dev/null 2>&1 || break
        done
    fi

    # has it stopped?
    kill -0 ${_pid} >/dev/null 2>&1 && util::err "failed to stop guest"
    echo "  * guest powered off"

    echo "  * taking second snapshot"
    _snap2="$(date +'%Y%m%d%H%M%S')"
    zfs snapshot -r "${VM_DS_ZFS_DATASET}/${_name}@${_snap2}"

    echo "  * sending incrmental changes to remote host"
    zfs send -Ri "${_snap1}" "${VM_DS_ZFS_DATASET}/${_name}@${_snap2}" | socat - "TCP4:${_host}:12001"
    echo "  * second stage completed"

    echo "  * removing snapshots"
    zfs destroy "${VM_DS_ZFS_DATASET}/${_name}@${_snap1}"
    zfs destroy "${VM_DS_ZFS_DATASET}/${_name}@${_snap2}"
    echo "  * done"
}