Class: VpsAdmin::CLI::Commands::BackupDataset

Inherits:
BaseDownload
  • Object
show all
Defined in:
lib/vpsadmin/cli/commands/backup_dataset.rb

Direct Known Subclasses

BackupVps

Defined Under Namespace

Classes: LocalSnapshot

Instance Method Summary collapse

Methods inherited from BaseDownload

#initialize

Constructor Details

This class inherits a constructor from VpsAdmin::CLI::Commands::BaseDownload

Instance Method Details

#exec(args) ⇒ Object 



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# File 'lib/vpsadmin/cli/commands/backup_dataset.rb', line 90

def exec(args)
  if args.size == 1 && /^\d+$/ !~ args[0]
    fs = args[0]

    ds_id = read_dataset_id(fs)

    ds = if ds_id
           @api.dataset.show(ds_id)
         else
           dataset_chooser
         end

  elsif args.size != 2
    warn 'Provide DATASET_ID and FILESYSTEM arguments'
    exit(false)

  else
    ds = @api.dataset.show(args[0].to_i)
    fs = args[1]
  end

  check_dataset_id!(ds, fs)
  snapshots = ds.snapshot.list

  local_state = parse_tree(fs)

  # - Find out current history ID
  # - If there are snapshots with this ID that are not present locally,
  #   download them
  #   - If the dataset for this history ID does not exist, create it
  #   - If it exists, check what snapshots are there and make an incremental
  #     download

  remote_state = {}

  snapshots.each do |s|
    remote_state[s.history_id] ||= []
    remote_state[s.history_id] << s
  end

  if remote_state[ds.current_history_id].nil? \
     || remote_state[ds.current_history_id].empty?
    exit_msg(
      "Nothing to transfer: no snapshots with history id #{ds.current_history_id}",
      error: @opts[:no_snapshots_error]
    )
  end

  for_transfer = []

  latest_local_snapshot = local_state[ds.current_history_id] \
                          && local_state[ds.current_history_id].last
  found_latest = false

  # This is the first run within this history id, no local snapshots are
  # present
  if !latest_local_snapshot && @opts[:init_snapshots]
    remote_state[ds.current_history_id] =
      remote_state[ds.current_history_id].last(@opts[:init_snapshots])
  end

  remote_state[ds.current_history_id].each do |snap|
    found = false

    local_state.each_value do |local_snapshots|
      found = local_snapshots.detect { |s| s.name == snap.name }
      break if found
    end

    if !found_latest && latest_local_snapshot \
       && latest_local_snapshot.name == snap.name
      found_latest = true

    elsif latest_local_snapshot
      next unless found_latest
    end

    for_transfer << snap unless found
  end

  if for_transfer.empty?
    if found_latest
      exit_msg(
        'Nothing to transfer: all snapshots with history id ' \
        "#{ds.current_history_id} are already present locally",
        error: @opts[:no_snapshots_error]
      )

    else
      exit_msg(<<~END
        Unable to transfer: the common snapshot has not been found

        This can happen when the latest local snapshot was deleted from the server,
        i.e. you have not backed up this dataset for quite some time.

        You can either rename or destroy the whole current history id:

          zfs rename #{fs}/#{ds.current_history_id} #{fs}/#{ds.current_history_id}.old

        or

          zfs list -r -t all #{fs}/#{ds.current_history_id}
          zfs destroy -r #{fs}/#{ds.current_history_id}

        which will destroy all snapshots with this history id.

        You can also destroy the local backup completely or backup to another dataset
        and start anew.
      END
              )
    end
  end

  unless @opts[:quiet]
    puts "Will download #{for_transfer.size} snapshots:"
    for_transfer.each { |s| puts "  @#{s.name}" }
    puts
  end

  if @opts[:pretend]
    pretend_state = local_state.clone
    pretend_state[ds.current_history_id] ||= []
    pretend_state[ds.current_history_id].concat(for_transfer.map do |s|
      LocalSnapshot.new(s.name, ds.current_history_id, Time.iso8601(s.created_at).to_i)
    end)

    rotate(fs, pretend: pretend_state) if @opts[:rotate]

  else
    # Find the common snapshot between server and localhost, so that the transfer
    # can be incremental.
    shared_name = local_state[ds.current_history_id] \
                  && !local_state[ds.current_history_id].empty? \
                  && local_state[ds.current_history_id].last.name
    shared = nil

    if shared_name
      shared = remote_state[ds.current_history_id].detect { |s| s.name == shared_name }

      for_transfer.insert(0, shared) if shared && !for_transfer.detect { |s| s.id == shared.id }
    end

    write_dataset_id!(ds, fs) unless written_dataset_id?
    transfer(local_state, for_transfer, ds.current_history_id, fs)
    rotate(fs) if @opts[:rotate]
  end
end

#options(opts) ⇒ Object 



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# File 'lib/vpsadmin/cli/commands/backup_dataset.rb', line 15

def options(opts)
  @opts = {
    rotate: true,
    min_snapshots: 30,
    max_snapshots: 45,
    max_age: 30,
    attempts: 10,
    checksum: true,
    delete_after: true,
    sudo: true
  }

  opts.on('-p', '--pretend', 'Print what would the program do') do
    @opts[:pretend] = true
  end

  opts.on('-r', '--[no-]rotate', 'Delete old snapshots (enabled)') do |r|
    @opts[:rotate] = r
  end

  opts.on('-m', '--min-snapshots N', Integer, 'Keep at least N snapshots (30)') do |m|
    exit_msg('--min-snapshots must be greater than zero') if m <= 0
    @opts[:min_snapshots] = m
  end

  opts.on('-M', '--max-snapshots N', Integer, 'Keep at most N snapshots (45)') do |m|
    exit_msg('--max-snapshots must be greater than zero') if m <= 0
    @opts[:max_snapshots] = m
  end

  opts.on('-a', '--max-age N', Integer, 'Delete snapshots older then N days (30)') do |m|
    exit_msg('--max-age must be greater than zero') if m <= 0
    @opts[:max_age] = m
  end

  opts.on('-x', '--max-rate N', Integer, 'Maximum download speed in kB/s') do |r|
    exit_msg('--max-rate must be greater than zero') if r <= 0
    @opts[:max_rate] = r
  end

  opts.on('-q', '--quiet', 'Print only errors') do |q|
    @opts[:quiet] = q
  end

  opts.on('-s', '--safe-download', 'Download to a temp file (needs 2x disk space)') do |s|
    @opts[:safe] = s
  end

  opts.on('--retry-attemps N', Integer, 'Retry N times to recover from download error (10)') do |n|
    exit_msg('--retry-attempts must be greater than zero') if n <= 0
    @opts[:attempts] = n
  end

  opts.on('-i', '--init-snapshots N', Integer, 'Download max N snapshots initially') do |s|
    exit_msg('--init-snapshots must be greater than zero') if s <= 0
    @opts[:init_snapshots] = s
  end

  opts.on('--[no-]checksum', 'Verify checksum of the downloaded data (enabled)') do |c|
    @opts[:checksum] = c
  end

  opts.on('-d', '--[no-]delete-after', 'Delete the file from the server after successful download (enabled)') do |d|
    @opts[:delete_after] = d
  end

  opts.on('--no-snapshots-as-error', 'Consider no snapshots to download as an error') do
    @opts[:no_snapshots_error] = true
  end

  opts.on('--[no-]sudo', 'Use sudo to run zfs if not run as root (enabled)') do |s|
    @opts[:sudo] = s
  end
end