patch tool to convert VM disk snapshots from tree to flat ones

allow_orphans.rb

# -------------------------------------------------------------------------- #
# Copyright 2002-2017, 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.                                             #
#--------------------------------------------------------------------------- #

if !ONE_LOCATION
    LOG_LOCATION = "/var/log/one"
else
    LOG_LOCATION = ONE_LOCATION + "/var"
end

LOG = LOG_LOCATION + "/onedb-allow_orphans.log"

require 'nokogiri'

module OneDBPatch
    VERSION_MIN = "5.0.0"
    VERSION_MAX = "5.5.0"

    def is_hot_patch(ops)
        return false
    end

    def check_db_version(ops)
        db_version = read_db_version()

        version = Gem::Version.new(db_version[:version])

        if (version  < Gem::Version.new(VERSION_MIN)) ||
           (version >= Gem::Version.new(VERSION_MAX))
        then
            raise <<-EOT
Version mismatch: patch file is for version
Shared: #{VERSION_MIN} to #{VERSION_MAX} (excluding)

Current database is version
Shared: #{db_version[:version]}
EOT
        end
    end

    def add_element(elem, name)
        return elem.add_child(elem.document.create_element(name))
    end

    def add_cdata(elem, name, text)
        # The cleaner doc.create_cdata(txt) is not supported in
        # old versions of nokogiri
        return add_element(elem, name).add_child(
                        Nokogiri::XML::CDATA.new(elem.document(), text))
    end

    def add_allow_orphans(ele, val, type)
        did = ele.xpath("DISK_ID").text
        if (did) then
            ele.search("ALLOW_ORPHANS").remove
            add_cdata(ele, "ALLOW_ORPHANS", val)
            elem = ele.search("ALLOW_ORPHANS")
            puts "   #{type} DISK_ID:#{did} :: #{elem}"
        end
    end

    def patch(ops)

        init_log_time()

        puts "This tool will convert the tree of disk snapshots to orphans."

        @db.transaction do
            @db.fetch("SELECT * FROM vm_pool") do |row|
                doc = Nokogiri::XML(row[:body],nil,NOKOGIRI_ENCODING){|c| c.default_xml.noblanks}

                next if row[:state] == 6 # skip VMs in state DONE

                puts " VM_ID:#{row[:oid]} state:#{row[:state]} lcm_state:#{row[:lcm_state]}"

                doc.xpath("/VM/TEMPLATE/DISK").each do |disk|
                   add_allow_orphans(disk, "YES", "DISKS")
                end

                doc.xpath("/VM/SNAPSHOTS").each do |snaps|
                   add_allow_orphans(snaps, "YES", "SNAPS")
                   snaps.xpath("SNAPSHOT").each do |snap|
                       snap.search("CHILDREN").remove
                       snap.search("PARENT").remove
                       add_cdata(snap, "PARENT", "-1")
                       parent_ele = snap.search("PARENT")
                       sid = snap.xpath("ID").text
                       puts "        SNAPSHOT_ID:#{sid} :: #{parent_ele}"
                   end
                end

                body = doc.root.to_s
                @db[:vm_pool].where(oid: row[:oid]).update(body: body)
            end

            log_time()
        end
        return true
    end
end