one/share/hooks/autostart/host

#!/usr/bin/env ruby

# -------------------------------------------------------------------------- #
# Copyright 2002-2021, OpenNebula Project, OpenNebula Systems                #
#                                                                            #
# 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.                                             #
#--------------------------------------------------------------------------- #

##############################################################################
# Hook configuration
##############################################################################
# - Create /var/lib/one/remotes/hooks/autostart folder if it doesn't exist
# - Create hook template as follows:
#     $ cat > autostart-host.tmpl <<EOF
#     NAME            = autostart-host
#     TYPE            = state
#     COMMAND         = autostart/host
#     ARGUMENTS       = \$TEMPLATE
#     ARGUMENTS_STDIN = yes
#     RESOURCE        = HOST
#     STATE           = MONITORED
#     EOF
# - Create hook as follows:
#     $ onehook create autostart-hook.tmpl
##############################################################################

##############################################################################
# Environment Configuration
##############################################################################
ONE_LOCATION = ENV['ONE_LOCATION']

if !ONE_LOCATION
    RUBY_LIB_LOCATION = '/usr/lib/one/ruby'
    GEMS_LOCATION     = '/usr/share/one/gems'
    VMDIR             = '/var/lib/one'
    CONFIG_FILE       = '/var/lib/one/config'
    LOG_FILE          = '/var/log/one/autostart-host.log'
else
    RUBY_LIB_LOCATION = ONE_LOCATION + '/lib/ruby'
    GEMS_LOCATION     = ONE_LOCATION + '/share/gems'
    VMDIR             = ONE_LOCATION + '/var'
    CONFIG_FILE       = ONE_LOCATION + '/var/config'
    LOG_FILE          = ONE_LOCATION + '/var/autostart-host.log'
end

if File.directory?(GEMS_LOCATION)
    real_gems_path = File.realpath(GEMS_LOCATION)
    if !defined?(Gem) || Gem.path != [real_gems_path]
        $LOAD_PATH.reject! {|l| l =~ /vendor_ruby/ }
        require 'rubygems'
        Gem.use_paths(real_gems_path)
    end
end

$LOAD_PATH << RUBY_LIB_LOCATION

require 'opennebula'
include OpenNebula

require 'getoptlong'
require 'base64'
require 'open3'


################################################################################
# Arguments
################################################################################

# Get arguments from standard input
standard_input = STDIN.read
ARGV.replace(standard_input.split(' '))


raw_host_template = Base64.decode64(ARGV[0])
xml_host_template = Nokogiri::XML(raw_host_template)

HOST_ID = xml_host_template.xpath('HOST/ID').text


################################################################################
# Methods
################################################################################

def log(msg, level="I")
    File.open(LOG_FILE, 'a') do |f|
        msg.lines do |l|
            f.puts "[#{Time.now}][HOST #{HOST_ID}][#{level}] #{l}"
        end
    end
end

def log_error(msg)
    log(msg, "E")
end

def exit_error
    log_error("Exiting due to previous error.")
    exit(-1)
end

################################################################################
# Main
################################################################################

log "OpenNebula Autostart Host Hook launched"

begin
    client = Client.new()
rescue Exception => e
    log_error e.to_s
    exit_error
end

host = OpenNebula::Host.new_with_id(HOST_ID, client)

rc   = host.info
if OpenNebula.is_error?(rc)
    log_error "#{rc.message}"
    exit_error
end

log "#{host.name}"

# Iterate over guest VMs
xml_host_template.xpath('HOST/VMS').text.split.each do |vm_id|
    vm = OpenNebula::VirtualMachine.new_with_id(vm_id, client)

    rc = vm.info
    if OpenNebula.is_error?(rc)
        log_error "vm #{vm_id}: error: #{rc.message}"
        next
    end

    # Skip if VM AUTOSTART not enabled
    autostart = vm['USER_TEMPLATE/AUTOSTART']
    if !autostart || (autostart != "true" && autostart != "yes")
        log "vm #{vm_id}: skip: autostart not enabled"
        next
    end

    # UNKNOWN state is set for active VMs when the host went to error state.
    # After the host comes back to ONLINE state if OpenNeubula monitor cannot
    # determine the state of active VMs, UNKNOWN state is kept.
    # Skip if LCM State is not UNKNOWN
    if vm.lcm_state_str != 'UNKNOWN'
        log "vm #{vm_id}: skip: lcm_state (#{vm.lcm_state_str}) is not 'UNKNOWN'"
        next
    end

    last_history_xpath = 'HISTORY_RECORDS/HISTORY[last()]'

    # HID (Host ID) in last history record of guest should match the host name.
    # Skip if HID in last history record of guest doesn't match the Host ID
    last_hid = vm["#{last_history_xpath}/HID"]
    if last_hid.to_i != host.id
        log "vm #{vm_id}: skip: last Host ID (#{last_hid}) "<<
            "does not match the Host ID (#{host.id})"
        next
    end

    # ACTION in last history record of guest is equal to 'none' if VM was
    # RUNNING before a host error or host reboot.
    # Skip if action in last history record of guest is not 'none'
    last_action = vm["#{last_history_xpath}/ACTION"]
    last_action_str = OpenNebula::VirtualMachine.get_history_action(last_action)
    if not %w{none live-migrate}.include?(last_action_str)
        log "vm #{vm_id}: skip: last_action (#{last_action_str}) is not 'none' or 'live-migrate'"
        next
    end

    # Autostart VM
    log "vm #{vm_id}: resume"
    rc = vm.resume

    log_error "vm: #{vm_id}: #{rc.message}" if OpenNebula.is_error?(rc)
end

exit 0