Module: ZfsMgmt::Restic

Included in:
ZfsMgr::Backup
Defined in:
lib/zfs_mgmt/restic.rb

Class Method Summary collapse

Class Method Details

.backup(backup_level: 2, options: {}) ⇒ Object 



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# File 'lib/zfs_mgmt/restic.rb', line 65

def self.backup(backup_level: 2,
                options: {})
  ZfsMgmt.zfs_managed_list(filter: options['filter'],
                           properties: ['name',
                                        'zfsmgmt:restic_backup',
                                        'zfsmgmt:restic_repository',
                                        'userrefs',
                                       ],
                           property_match: { 'zfsmgmt:restic_backup' => ['on','true'] }).each do |blob|
    zfs,props,zfs_snapshots = blob
    last_zfs_snapshot = zfs_snapshots.keys.sort { |a,b| zfs_snapshots[a]['creation'] <=> zfs_snapshots[b]['creation'] }.last
    zfs_snap_time = Time.at(zfs_snapshots[last_zfs_snapshot]['creation'])

    level = 0
    chain = []
    zfs_snap_parent = ''
    restic_snap_parent = ''
    (restic_snapshots,restic_snapshot_zfs_snapshot_index) = restic_snapshots(zfs,options,props)
    if restic_snapshot_zfs_snapshot_index.has_key?(last_zfs_snapshot)
      $logger.warn("backup of this snapshot #{last_zfs_snapshot} already exists in restic, cannot continue with backup of #{zfs}")
      next # next zfs filesystem to be backed up
    end
    if backup_level > 0 and restic_snapshots.count > 0
      # reverse (oldest first) sorted restic snapshots
      restic_snap_parent = restic_snapshots.filter { |rsnap|
        rsnap.has_key?('zfsmgmt:zfs') and rsnap['zfsmgmt:zfs'] == zfs and
          rsnap.has_key?('zfsmgmt:level') and rsnap['zfsmgmt:level'] < backup_level }.sort {
        |a,b| a['date_time'] <=> b['date_time'] }.last
      if restic_snap_parent and
        zfs_snapshots.has_key?(restic_snap_parent['zfsmgmt:snapshot']) and
        chain = valid_chain(restic_snap_parent,restic_snapshots,restic_snapshot_zfs_snapshot_index,[]) and
        chain.length > 0
        
        level = restic_snap_parent['zfsmgmt:level'] + 1
        zfs_snap_parent = restic_snap_parent['zfsmgmt:snapshot']
        $logger.debug("restic_snap_parent: level: #{restic_snap_parent['zfsmgmt:level']} snapshot: #{zfs_snap_parent}")
      else
        $logger.error("restic_snap_parent rejected: level: #{restic_snap_parent['zfsmgmt:level']} snapshot: #{restic_snap_parent['zfsmgmt:snapshot']}")
      end
      $logger.debug("chain of snapshots: #{chain}")
    end
    tags = [ 'zfsmgmt',
             "zfsmgmt:snapshot=#{last_zfs_snapshot}",
             "zfsmgmt:zfs=#{zfs}",
             "zfsmgmt:level=#{level}" ]
    com = [ ZfsMgmt.global_options['zfs_binary'], 'send', '-w', '-h', '-p' ]
    if level > 0
      if options[:intermediary]
        com.push('-I')
      else
        com.push('-i')
      end
      com.push(zfs_snap_parent)
      tags.push("zfsmgmt:parent=#{zfs_snap_parent}")
    end
    com.push( last_zfs_snapshot )
    com.push( '|', 'mbuffer', '-m', options[:buffer], '-q' )
    com.push( '|', options[:restic_binary], 'backup', '--stdin',
              '--stdin-filename', zfs, '--time', "\"#{zfs_snap_time.strftime('%F %T')}\"" )
    tags.each do |tag|
      com.push( '--tag', "\"#{tag}\"" )
    end
    if options.has_key?('limit_upload')
      com.push('--limit-upload', options['limit_upload'])
    end
    if options.has_key?('password_file')
      com.push('-p',options['password_file'])
    end
    if options.has_key?('repo')
      com.push('--repo', options['repo'])
    elsif props.has_key?('zfsmgmt:restic_repository')
      com.push( '--repo', props['zfsmgmt:restic_repository'] )
    end
    if options[:verbose]
      com.push('--verbose',options[:verbose])
    elsif $stdout.isatty
      com.push('-v')
    end
    unless ZfsMgmt.zfs_holds(last_zfs_snapshot).include?('zfsmgmt_restic')
      ZfsMgmt.zfs_hold('zfsmgmt_restic',last_zfs_snapshot)
    end
    ZfsMgmt.system_com(com)
    chain_snaps = chain.map do |rsnap|
      rsnap['zfsmgmt:snapshot']
    end
    zfs_snapshots.each do |s,d|
      d['userrefs'] == 0 and next
      chain_snaps.include?(s) and next
      s == last_zfs_snapshot and next
      if ZfsMgmt.zfs_holds(s).include?('zfsmgmt_restic')
        ZfsMgmt.zfs_release('zfsmgmt_restic',s)
      end
    end
  end
end

.restic_snapshots(zfs, options, props) ⇒ Object 



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# File 'lib/zfs_mgmt/restic.rb', line 4

def self.restic_snapshots(zfs,options,props)
  # query the restic database
  com = [ options[:restic_binary],
          'snapshots',
          '--json',
          '--tag', 'zfsmgmt',
          '--path', "/#{zfs}",
        ]
  if options.has_key?('password_file')
    com.push('-p',options['password_file'])
  end
  if options.has_key?('repo')
    com.push('--repo', options['repo'])
  elsif props.has_key?('zfsmgmt:restic_repository')
    com.push( '--repo', props['zfsmgmt:restic_repository'] )
  end

  $logger.info("#{com.join(' ')}")
  restic_output = %x(#{com.join(' ')})
  unless $?.success?
    $logger.error("unable to query the restic database")
    raise "unable to query the restic database"
  end
  restic_snapshots = JSON.parse(restic_output)
  restic_snapshot_zfs_snapshot_index = {}
  restic_snapshots.each do |snappy|
    snappy['date_time'] = DateTime.parse(snappy['time'])
    if snappy.has_key?('tags')
      snappy['tags'].each do |t|
        if m = /^(zfsmgmt:.+?)=(.+)/.match(t)
          if ['zfsmgmt:level'].include?(m[1])
            snappy[m[1]] = m[2].to_i
          else
            snappy[m[1]] = m[2]
          end
          if m[1] == 'zfsmgmt:snapshot'
            restic_snapshot_zfs_snapshot_index[m[2]] = snappy
          end
        end
      end
    end
  end
  return([restic_snapshots,restic_snapshot_zfs_snapshot_index])
end

.valid_chain(snap, restic_snapshots, restic_snapshot_zfs_snapshot_index, a) ⇒ Object 



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# File 'lib/zfs_mgmt/restic.rb', line 49

def self.valid_chain(snap,restic_snapshots,restic_snapshot_zfs_snapshot_index,a)
  if snap['zfsmgmt:level'] == 0
    a.push(snap)
    $logger.debug("found complete chain culminating in full backup of: #{snap['zfsmgmt:snapshot']}")
    return a
  elsif restic_snapshot_zfs_snapshot_index.has_key?(snap['zfsmgmt:parent'])
    a.push(snap)
    $logger.debug("found another link in the chain: #{snap['zfsmgmt:snapshot']} => #{snap['zfsmgmt:parent']}")
    return valid_chain(restic_snapshot_zfs_snapshot_index[snap['zfsmgmt:parent']],restic_snapshots,restic_snapshot_zfs_snapshot_index,a)
  else
    $logger.error("broken chain: looking for the parent of #{snap['zfsmgmt:snapshot']} (#{snap['zfsmgmt:parent']}) and failed to find")
    return []
  end
end