Add basic tarsnap stuff

lib/tarsnap.rb

@@ -0,0 +1,91 @@
+require 'pathname'
+require 'escape'
+
+class Tarsnap
+
+  class << self
+
+    attr_accessor :binary_mapping
+
+    def prefix
+      @prefix = lookup_default_prefix if !defined?(@prefix) || @prefix.to_s.strip.empty?
+      Pathname(@prefix)
+    end
+
+    def prefix=(value)
+      @prefix = value
+    end
+
+    def bin_path(name)
+      name = binary_mapping[name] if name.is_a?(Symbol)
+      name.include?('/') ? name : prefix.join("bin", name).to_s
+    end
+
+    def list
+      names = []
+      status, output = exec!(:tarsnap, "--list-archives")
+      output.each_line { |l| names << l.strip } if status
+      names
+    end
+
+    def delete!(name, options = {})
+      status, _ = exec!(:tarsnap, "-d", "-f", name, *hash_to_arguments(options))
+      status
+    end
+
+    def create!(name, *files)
+      options = extract_options(files)
+      status, _ = exec!(:tarsnap, "-c", "-f", name, *(hash_to_arguments(options) + files))
+      status
+    end
+
+    protected
+
+    def hash_to_arguments(options = {})
+      arguments = []
+      options.each_pair do |k, v|
+        case k.to_s
+        when "cd", "C"
+          arguments << "-C"
+          arguments << v.to_s
+        when "cache_dir", "cache-dir"
+          arguments << "--cachedir"
+          arguments << v.to_s
+        when "aggressive_networking", "aggressive-networking"
+          arguments << "--#{k ? "" : "no-"}aggressive-networking"
+        when "l", "check-links", "check_links"
+          arguments << "--check-links"
+        when "keyfile", "key_file", "key-file"
+          arguments << "--keyfile"
+          arguments << v.to_s
+        when "dry-run", "dry_run", "dry-run"
+          arguments << "--dry-run"
+        end
+      end
+      arguments
+    end
+
+    def exec!(key, *args)
+      binary = bin_path(key)
+      command = Escape.shell_command([binary] + args.map { |a| a.to_s }).to_s
+      output = `#{command}`
+      return $?.success?, output
+    end
+
+    def lookup_default_prefix
+      output = `which tarsnap`.strip
+      output.empty? ? '/usr/local' : File.dirname(output).gsub("/bin", "")
+    end
+
+    def extract_options(array)
+      array.last.is_a?(Hash) ? array.pop : {}
+    end
+
+  end
+
+  self.binary_mapping ||= {}
+  binary_mapping[:tarsnap]         = "tarsnap"
+  binary_mapping[:tarsnap_keygen]  = "tarsnap-keygen"
+  binary_mapping[:tarsnap_keymgmt] = "tarsnap-keymgmt"
+
+end

lib/tarsnap/backup.rb

@@ -0,0 +1,46 @@
+class Tarsnap::Backup
+
+  DATE_FORMAT   = "%Y%m%d"
+  FORMAT_REGEXP = /\d{4}\d{2}\d{2}/
+
+  DEFAULTS = {
+    :daily   => 7,
+    :weekly  => 3,
+    :monthly => 6
+  }
+
+  def initialize(name, options = {})
+    @name    = name
+    @options = DEFAULTS.merge(options)
+    @chdir   = options.delete(:cd)
+    @paths   = []
+  end
+
+  def add_archive(name)
+    @paths << "@#{name}"
+  end
+
+  def add_path(path)
+    @paths << path.to_s
+  end
+
+  def create!(date = Time.now)
+    archive_name = "#{@name}-#{date.utc.strftime(FORMAT_REGEXP)}"
+    args = generate_files
+    options = {}
+    options[:C] = @chdir if !@chdir.to_s.strip.empty?
+    args << options
+    Tarsnap.create!(archive_name, *args)
+  end
+
+  def archives
+    Tarsnap.list.grep(/^#{Regexp.escape(@name)}\-#{FORMAT_REGEXP}$/)
+  end
+
+  protected
+
+  def generate_files
+    @paths.map { |f| f.to_s }
+  end
+
+end