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#!/usr/bin/ruby
#
# Restore a file from the most recent backup, from the remote host.
#
$LOAD_PATH.unshift('/usr/lib/byteback')
$LOAD_PATH.unshift('./lib/')
require 'trollop'
#
# Show an error message and abort.
#
def fatal(str)
STDERR.puts(str)
exit(1)
end
#
# Run a remote command.
#
def ssh(*ssh_args)
args = ['ssh',
'-o', 'BatchMode=yes',
'-o', 'ConnectionAttempts=5',
'-o', 'ConnectTimeout=30',
'-o', 'ServerAliveInterval=60',
'-o', 'TCPKeepAlive=yes',
'-x', '-a',
'-i', @ssh_key,
'-l', @destination_user,
@destination_host
] +
ssh_args
.map { |a| a ? a : '' }
system(*args)
end
def list_files(pattern)
ssh('byteback-receive', '--list', pattern)
end
#
# We cannot use plain 'rsync' here because the receiver command will
# see that, and rewrite our arguments.
#
# To cater to this we have to wrap the rsync for the restore and we
# do that by setting "rsync-path" to point to the receiver program.
#
#
def restore_file(path, revision)
cmd = %w( rsync )
cmd += ['--rsh', 'ssh -o BatchMode=yes -x -a -i /etc/byteback/key -l byteback']
cmd += ['--rsync-path', 'restore --fake-super']
cmd += ['-aApzrX', '--numeric-ids']
cmd += ["#{@destination_host}:/#{revision}/#{path}", '.']
system(*cmd)
end
#
# Parse our command-line arguments
#
opts = Trollop.options do
banner "byteback-restore: Restore a file\n "
opt :file, 'The file to restore',
type: :string
opt :revision, "The version of the file to restore - default is 'latest'",
type: :string
opt :destination, 'Backup destination (i.e. user@host:/path)',
type: :string
opt :ssh_key, 'SSH key filename',
type: :string,
default: '/etc/byteback/key',
short: 'k'
end
#
# Setup default destination and key.
#
@destination = File.read('/etc/byteback/destination').chomp if
File.exist?('/etc/byteback/destination')
@ssh_key = '/etc/byteback/key' if File.exist?('/etc/byteback/key')
#
# Allow the command-line to override them.
#
@ssh_key = opts[:ssh_key] unless opts[:ssh_key].nil?
@destination = opts[:destination] unless opts[:destination].nil?
#
# Check our destination is well-formed
#
if @destination =~ /^(?:(.+)@)?([^@:]+):(.+)?$/
@destination_user, @destination_host, @destination_path = [Regexp.last_match(1), Regexp.last_match(2), Regexp.last_match(3)]
else
fatal('Destination must be a remote path, e.g. ssh@host.com:/store/backups')
end
#
# If the user didn't specify a file then we're not restoring anything,
# and we should abort.
#
if opts[:file].nil?
fatal('You must specify a file to restore')
end
#
# If the user specified a file, but not a revision, then we list
# the available revisions.
#
if opts[:revision].nil?
list_files(opts[:file])
exit(0)
end
#
# Restore a file
#
restore_file(opts[:file], opts[:revision])
exit(0)
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