Class: OsCtld::Container::Importer

Inherits:
Object
  • Object
show all
Includes:
OsCtl::Lib::Utils::Log, OsCtl::Lib::Utils::System
Defined in:
lib/osctld/container/importer.rb

Overview

An interface for reading tar archives generated by OsCtl::Lib::Container::Exporter

Constant Summary collapse

BLOCK_SIZE = 
32 * 1024

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(pool, io, ct_id: nil, image_file: nil) ⇒ Importer

Returns a new instance of Importer.



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# File 'lib/osctld/container/importer.rb', line 15

def initialize(pool, io, ct_id: nil, image_file: nil)
  @pool = pool
  @tar = Gem::Package::TarReader.new(io)
  @image_file = image_file
  @ct_id = ct_id
end

Instance Attribute Details

#image_file ⇒ Object (readonly, protected)

Returns the value of attribute image_file.



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# File 'lib/osctld/container/importer.rb', line 247

def image_file
  @image_file
end

#metadata ⇒ Object (readonly, protected)

Returns the value of attribute metadata.



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# File 'lib/osctld/container/importer.rb', line 247

def metadata
  @metadata
end

#pool ⇒ Object (readonly, protected)

Returns the value of attribute pool.



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# File 'lib/osctld/container/importer.rb', line 247

def pool
  @pool
end

#tar ⇒ Object (readonly, protected)

Returns the value of attribute tar.



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# File 'lib/osctld/container/importer.rb', line 247

def tar
  @tar
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/osctld/container/importer.rb', line 241

def close
  tar.close
end

#copy_file_to_disk(entry, dst) ⇒ Object (protected)

Copy file from the tar archive to disk

Parameters:

  • entry (Gem::Package::TarReader::Entry)
  • dst (String) 


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# File 'lib/osctld/container/importer.rb', line 389

def copy_file_to_disk(entry, dst)
  File.open(dst, 'w', entry.header.mode & 0o7777) do |df|
    df.write(entry.read(BLOCK_SIZE)) until entry.eof?
  end
end

#create_datasets(builder, accept_existing: false) ⇒ Object

Create the root and all descendants datasets

Parameters:



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# File 'lib/osctld/container/importer.rb', line 190

def create_datasets(builder, accept_existing: false)
  datasets(builder).each do |ds|
    next if accept_existing && ds.exist?

    builder.create_dataset(ds, mapping: true, parents: ds.root?)
  end
end

#create_new_user ⇒ User (protected)

Returns:



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# File 'lib/osctld/container/importer.rb', line 285

def create_new_user
  name = ct_id

  db = DB::Users.find(name, pool)
  return db if db

  # The user does not exist, create him
  Commands::User::Create.run!(
    pool: pool.name,
    name:,
    standalone: false
  )

  DB::Users.find(name, pool) || (raise 'expected user')
end

#ct_id ⇒ Object 



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# File 'lib/osctld/container/importer.rb', line 52

def ct_id
  @ct_id || metadata['container']
end

#datasets(builder) ⇒ Array<OsCtl::Lib::Zfs::Dataset>

Parameters:

Returns:

  • (Array<OsCtl::Lib::Zfs::Dataset>) 


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# File 'lib/osctld/container/importer.rb', line 230

def datasets(builder)
  return @datasets if @datasets

  @datasets = [builder.ctrc.dataset] + metadata['datasets'].map do |name|
    OsCtl::Lib::Zfs::Dataset.new(
      File.join(builder.ctrc.dataset.name, name),
      base: builder.ctrc.dataset.name
    )
  end
end

#get_container_config ⇒ Hash

Returns:

  • (Hash) 


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# File 'lib/osctld/container/importer.rb', line 121

def get_container_config
  OsCtl::Lib::ConfigFile.load_yaml(tar.seek('config/container.yml', &:read))
end

#get_or_create_group ⇒ Group

Load the group from the archive and register it, or create a new group

If a group with the same name already exists and all its parameters are the same, the existing group is returned. Otherwise an exception is raised.

Returns:



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# File 'lib/osctld/container/importer.rb', line 143

def get_or_create_group
  if has_group?
    name = metadata['group']

    db = DB::Groups.find(name, pool)
    grp = load_group

    if db.nil?
      # The group does not exist, create it
      Commands::Group::Create.run!(
        pool: pool.name,
        name: grp.name
      )

      return DB::Groups.find(name, pool) || (raise 'expected group')
    end

    db

  else
    DB::Groups.default(pool)
  end
end

#get_or_create_user ⇒ User

Load the user from the archive and register him, or create a new user

If a user with the same name already exists and all his parameters are the same, the existing user is returned. Otherwise an exception is raised.

Returns:



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# File 'lib/osctld/container/importer.rb', line 130

def get_or_create_user
  if has_user?
    load_or_create_user
  else
    create_new_user
  end
end

#group_name ⇒ Object 



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# File 'lib/osctld/container/importer.rb', line 44

def group_name
  metadata['group']
end

#has_ct_id? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/osctld/container/importer.rb', line 56

def has_ct_id?
  !ct_id.nil?
end

#has_group? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/osctld/container/importer.rb', line 48

def has_group?
  !group_name.nil?
end

#has_user? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/osctld/container/importer.rb', line 40

def has_user?
  !user_name.nil?
end

#import_all_datasets(builder) ⇒ Object

Import all datasets

Parameters:



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# File 'lib/osctld/container/importer.rb', line 200

def import_all_datasets(builder)
  case metadata['format']
  when 'zfs'
    import_streams(builder, datasets(builder))

  when 'tar'
    unpack_rootfs(builder)

  else
    raise "unsupported archive format '#{metadata['format']}'"
  end
end

#import_root_dataset(builder) ⇒ Object

Import just the root dataset

Parameters:



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# File 'lib/osctld/container/importer.rb', line 215

def import_root_dataset(builder)
  case metadata['format']
  when 'zfs'
    import_streams(builder, [datasets(builder).first])

  when 'tar'
    unpack_rootfs(builder)

  else
    raise "unsupported archive format '#{metadata['format']}'"
  end
end

#import_stream(builder, ds, name, required) ⇒ Object (protected) 



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# File 'lib/osctld/container/importer.rb', line 352

def import_stream(builder, ds, name, required)
  raise 'image_file needs to be set for import_stream()' if image_file.nil?

  found = nil

  stream_names(name).each do |file, compression|
    tf = tar.find { |entry| entry.full_name == file }

    if tf.nil?
      tar.rewind
      next
    end

    found = [tf, compression]
    break
  end

  if found.nil?
    tar.rewind
    raise "unable to import: #{name} not found" if required

    return
  end

  entry, compression = found
  builder.from_tar_stream(image_file, entry.full_name, compression, ds)
  tar.rewind
end

#import_streams(builder, datasets) ⇒ Object (protected)

Load ZFS data streams from the archive and write them to appropriate datasets

Parameters:



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# File 'lib/osctld/container/importer.rb', line 306

def import_streams(builder, datasets)
  datasets.each do |ds|
    import_stream(builder, ds, File.join(ds.relative_name, 'base'), true)
    import_stream(builder, ds, File.join(ds.relative_name, 'incremental'), false)
  end

  tar.seek('snapshots.yml') do |entry|
    snapshots = OsCtl::Lib::ConfigFile.load_yaml(entry.read)

    datasets.each do |ds|
      snapshots.each { |snap| zfs(:destroy, nil, "#{ds}@#{snap}") }
    end
  end
end

#install_user_hook_scripts(ct) ⇒ Object

Load user-defined script hooks from the archive and install them

Parameters:



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# File 'lib/osctld/container/importer.rb', line 169

def install_user_hook_scripts(ct)
  tar.each do |entry|
    next unless entry.full_name.start_with?('hooks/')

    name = entry.full_name[('hooks/'.length - 1)..]

    if entry.directory?
      FileUtils.mkdir_p(
        File.join(ct.user_hook_script_dir, name),
        mode: entry.header.mode & 0o7777
      )
    elsif entry.file?
      copy_file_to_disk(entry, File.join(ct.user_hook_script_dir, name))
    end
  end
end

#load_ct(opts) ⇒ Container

Create a new instance of OsCtld::Container as described by the tar archive

The returned CT is not registered in the internal database, it may even conflict with a CT already registered in the database.

Parameters:

  • opts (Hash) —

    options

Options Hash (opts):

Returns:



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# File 'lib/osctld/container/importer.rb', line 103

def load_ct(opts)
  id = opts[:id] || metadata['container']
  user = opts[:user] || get_or_create_user
  group = opts[:group] || get_or_create_group
  ct_opts = opts[:ct_opts] || {}
  ct_opts[:load_from] = tar.seek('config/container.yml', &:read)

  Container.new(
    pool,
    id,
    user,
    group,
    opts[:dataset] || Container.default_dataset(pool, id),
    ct_opts
  )
end

#load_group ⇒ Group?

Create a new instance of Group as described by the tar archive

The returned group is not registered in the internal database, it may even conflict with a group already registered in the database.

Returns:



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# File 'lib/osctld/container/importer.rb', line 80

def load_group
  return unless has_group?

  Group.new(
    pool,
    metadata['group'],
    config: tar.seek('config/group.yml', &:read),
    devices: false
  )
end

#load_metadata ⇒ Object

Load metadata describing the archive

Loading the metadata is the first thing that should be done, because all other methods depend on its result.



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# File 'lib/osctld/container/importer.rb', line 26

def load_metadata
  ret = tar.seek('metadata.yml') do |entry|
    OsCtl::Lib::ConfigFile.load_yaml(entry.read)
  end
  raise 'metadata.yml not found' unless ret

  @metadata = ret
  ret
end

#load_or_create_user ⇒ User (protected)

Returns:



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# File 'lib/osctld/container/importer.rb', line 250

def load_or_create_user
  name = metadata['user']

  db = DB::Users.find(name, pool)
  u = load_user

  if db.nil?
    # The user does not exist, create him
    Commands::User::Create.run!(
      pool: pool.name,
      name: u.name,
      ugid: u.ugid,
      uid_map: u.uid_map.export,
      gid_map: u.gid_map.export
    )

    return DB::Users.find(name, pool) || (raise 'expected user')
  end

  # Free the newly allocated ugid, use ugid from the existing user
  UGidRegistry.remove(u.ugid) if u.ugid != db.ugid

  %i[uid_map gid_map].each do |param|
    mine = db.send(param)
    other = u.send(param)
    next if mine == other

    raise "user #{pool.name}:#{name} already exists: #{param} mismatch: " \
          "existing #{mine}, trying to import #{other}"
  end

  db
end

#load_user ⇒ User?

Create a new instance of User as described by the tar archive

The returned user is not registered in the internal database, it may even conflict with a user already registered in the database.

Returns:



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# File 'lib/osctld/container/importer.rb', line 65

def load_user
  return unless has_user?

  User.new(
    pool,
    metadata['user'],
    config: tar.seek('config/user.yml', &:read)
  )
end

#stream_names(name) ⇒ Object (protected) 



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# File 'lib/osctld/container/importer.rb', line 381

def stream_names(name)
  base = File.join('rootfs', "#{name}.dat")
  [[base, :off], ["#{base}.gz", :gzip]]
end

#unpack_rootfs(builder) ⇒ Object (protected)

Parameters:



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# File 'lib/osctld/container/importer.rb', line 322

def unpack_rootfs(builder)
  raise 'image_file needs to be set for import_stream()' if image_file.nil?

  # Ensure the dataset is mounted
  builder.ctrc.dataset.mount(recursive: true)

  # Create private/
  builder.setup_rootfs

  tf = tar.find { |entry| entry.full_name == 'rootfs/base.tar.gz' }
  raise 'rootfs archive not found' if tf.nil?

  tar.rewind

  commands = [
    ['tar', '-xOf', image_file, tf.full_name],
    ['tar', '--xattrs-include=security.capability', '--xattrs', '-xz', '-C', builder.ctrc.rootfs]
  ]

  command_string = commands.map { |c| c.join(' ') }.join(' | ')

  pid = Process.spawn(command_string)
  Process.wait(pid)

  return unless $?.exitstatus != 0

  raise "failed to unpack rootfs: command '#{command_string}' " \
        "exited with #{$?.exitstatus}"
end

#user_name ⇒ Object 



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# File 'lib/osctld/container/importer.rb', line 36

def user_name
  metadata['user']
end