Class: OsCtl::Lib::Exporter::Zfs
- Includes:
- Utils::Log, Utils::System
- Defined in:
- lib/libosctl/exporter/zfs.rb
Overview
Handles dumping containers as ZFS streams into tar archives
Usage:
exporter.dump_rootfs do
# Create a snapshot a dump it
exporter.dump_base
# Create another snapshot and dump it as an incremental stream
# from the base snapshot
exporter.dump_incremental
end
Constant Summary
Constants inherited from Base
Base::BLOCK_SIZE, Base::DIR_MODE, Base::FILE_MODE
Instance Attribute Summary collapse
-
#base_snap ⇒ Object
readonly
protected
Returns the value of attribute base_snap.
-
#snapshots ⇒ Object
readonly
protected
Returns the value of attribute snapshots.
Attributes inherited from Base
Instance Method Summary collapse
-
#dump_base ⇒ Object
Dump initial data stream.
- #dump_file_name(compression, name) ⇒ Object protected
-
#dump_incremental(from_snap: nil) ⇒ Object
Dump incremental data stream from the base stream.
-
#dump_rootfs { ... } ⇒ Object
Method used to wrap dumping of base and incremental data streams of rootfs.
- #dump_stream(name, dataset, snap, from_snap = nil) ⇒ Object protected
-
#each_dataset {|ds| ... } ⇒ Object
protected
Iterate over all datasets.
-
#each_dataset_dir {|ds, dir_name| ... } ⇒ Object
protected
Iterate over all datasets and yield the dataset along with directory name for the tar archive, where its streams will be stored.
-
#each_dataset_file(name) {|ds, fname| ... } ⇒ Object
protected
Iterate over all datasets and yield the dataset along with file name for the archive.
- #format ⇒ Object
- #get_compression(dataset) ⇒ Object protected
-
#initialize(*_) ⇒ Zfs
constructor
A new instance of Zfs.
- #process_stream(compression, stream, tf) ⇒ Object protected
- #snapshot(dataset, type) ⇒ Object protected
- #snapshot_name(type) ⇒ Object protected
- #zfs_send ⇒ Object protected
Methods included from Utils::System
#repeat_on_failure, #syscmd, #zfs
Methods included from Utils::Log
Methods inherited from Base
#add_file_from_disk, #close, #dump_configs, #dump_metadata, #dump_user_hook_scripts
Constructor Details
#initialize(*_) ⇒ Zfs
Returns a new instance of Zfs.
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# File 'lib/libosctl/exporter/zfs.rb', line 20 def initialize(*_) super @datasets = ct.datasets[1..-1] # skip the root dataset @snapshots = [] end |
Instance Attribute Details
#base_snap ⇒ Object (readonly, protected)
Returns the value of attribute base_snap.
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# File 'lib/libosctl/exporter/zfs.rb', line 79 def base_snap @base_snap end |
#snapshots ⇒ Object (readonly, protected)
Returns the value of attribute snapshots.
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# File 'lib/libosctl/exporter/zfs.rb', line 79 def snapshots @snapshots end |
Instance Method Details
#dump_base ⇒ Object
Dump initial data stream
Should be called from within the block given to #dump_rootfs.
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# File 'lib/libosctl/exporter/zfs.rb', line 55 def dump_base @base_snap = snapshot(ct.dataset, 'base') each_dataset_file('base') do |ds, file| dump_stream(file, ds, base_snap) end end |
#dump_file_name(compression, name) ⇒ Object (protected)
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# File 'lib/libosctl/exporter/zfs.rb', line 169 def dump_file_name(compression, name) base = File.join('rootfs', "#{name}.dat") case compression when :gzip "#{base}.gz" else base end end |
#dump_incremental(from_snap: nil) ⇒ Object
Dump incremental data stream from the base stream
Should be called from within the block given to #dump_rootfs.
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# File 'lib/libosctl/exporter/zfs.rb', line 66 def dump_incremental(from_snap: nil) snap = snapshot(ct.dataset, 'incr') each_dataset_file('incremental') do |ds, file| dump_stream(file, ds, snap, from_snap || base_snap) end end |
#dump_rootfs { ... } ⇒ Object
Method used to wrap dumping of base and incremental data streams of rootfs
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# File 'lib/libosctl/exporter/zfs.rb', line 30 def dump_rootfs tar.mkdir('rootfs', DIR_MODE) each_dataset_dir do |_ds, dir| tar.mkdir(File.join('rootfs', dir), DIR_MODE) end yield snapshots.reverse! each_dataset do |ds| snapshots.each do |snap| zfs(:destroy, '', "#{ds}@#{snap}") end end tar.add_file('snapshots.yml', FILE_MODE) do |tf| tf.write(ConfigFile.dump_yaml(snapshots)) end end |
#dump_stream(name, dataset, snap, from_snap = nil) ⇒ Object (protected)
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# File 'lib/libosctl/exporter/zfs.rb', line 122 def dump_stream(name, dataset, snap, from_snap = nil) compression = get_compression(dataset) if from_snap cmd = "#{zfs_send} -I @#{from_snap} #{dataset}@#{snap}" else cmd = "#{zfs_send} #{dataset}@#{snap}" end tar.add_file(dump_file_name(compression, name), FILE_MODE) do |tf| IO.popen("exec #{cmd}") do |io| process_stream(compression, io, tf) end end end |
#each_dataset {|ds| ... } ⇒ Object (protected)
Iterate over all datasets
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# File 'lib/libosctl/exporter/zfs.rb', line 83 def each_dataset(&block) block.call(ct.dataset) datasets.each(&block) end |
#each_dataset_dir {|ds, dir_name| ... } ⇒ Object (protected)
Iterate over all datasets and yield the dataset along with directory name for the tar archive, where its streams will be stored.
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# File 'lib/libosctl/exporter/zfs.rb', line 93 def each_dataset_dir each_dataset do |ds| yield(ds, ds.relative_name) end end |
#each_dataset_file(name) {|ds, fname| ... } ⇒ Object (protected)
Iterate over all datasets and yield the dataset along with file name for the archive.
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# File 'lib/libosctl/exporter/zfs.rb', line 105 def each_dataset_file(name) each_dataset_dir do |ds, dir| yield(ds, File.join(dir, name)) end end |
#format ⇒ Object
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# File 'lib/libosctl/exporter/zfs.rb', line 74 def format :zfs end |
#get_compression(dataset) ⇒ Object (protected)
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# File 'lib/libosctl/exporter/zfs.rb', line 153 def get_compression(dataset) case opts[:compression] when :auto if !opts[:compressed_send] :gzip elsif zfs(:get, "-H -o value compression", dataset).output.strip == 'off' :gzip else :off end else opts[:compression].to_sym end end |
#process_stream(compression, stream, tf) ⇒ Object (protected)
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# File 'lib/libosctl/exporter/zfs.rb', line 138 def process_stream(compression, stream, tf) case compression when :gzip gz = Zlib::GzipWriter.new(tf) gz.write(stream.read(BLOCK_SIZE)) until stream.eof? gz.close when :off tf.write(stream.read(BLOCK_SIZE)) until stream.eof? else fail "unexpected compression type '#{compression}'" end end |
#snapshot(dataset, type) ⇒ Object (protected)
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# File 'lib/libosctl/exporter/zfs.rb', line 115 def snapshot(dataset, type) snap = snapshot_name(type) zfs(:snapshot, '-r', "#{dataset}@#{snap}") snapshots << snap snap end |
#snapshot_name(type) ⇒ Object (protected)
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# File 'lib/libosctl/exporter/zfs.rb', line 111 def snapshot_name(type) "osctl-#{type}-#{Time.now.to_i}" end |
#zfs_send ⇒ Object (protected)
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# File 'lib/libosctl/exporter/zfs.rb', line 181 def zfs_send if opts[:compressed_send] 'zfs send -c' else 'zfs send' end end |