Class: System

Inherits:
Object show all
Defined in:
lib/system.rb

Overview

System and its subclasses are used to represent systems that are to be inspected.

It abstracts common inspection tasks that need to be run, like executing commands or running “kiwi –describe”. Different implementations, e.g. for local or ssh-accessed systems are done in the according subclasses.

Direct Known Subclasses

DockerSystem, LocalSystem, RemoteSystem

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#locale ⇒ Object 



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# File 'lib/system.rb', line 135

def locale
  @locale || "C"
end

Class Method Details

.for(host, opts = {}) ⇒ Object 



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# File 'lib/system.rb', line 36

def self.for(host, opts = {})
  if host && host != "localhost"
    RemoteSystem.new(host, opts)
  else
    LocalSystem.new
  end
end

Instance Method Details

#arch ⇒ Object 



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# File 'lib/system.rb', line 131

def arch
  run_command("uname", "-m", stdout: :capture).chomp
end

#check_create_archive_dependencies ⇒ Object 



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# File 'lib/system.rb', line 63

def check_create_archive_dependencies
  check_requirement("tar", "--version")
  check_requirement("gzip", "--version")
end

#check_requirement(commands, *args) ⇒ Object

checks if the required command can be executed on the target system

Raises:



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# File 'lib/system.rb', line 45

def check_requirement(commands, *args)
  commands = Array(commands)
  commands.each do |command|
    begin
      run_command(command, *args)
      return command
    rescue Cheetah::ExecutionFailed
    end
  end
  raise Machinery::Errors::MissingRequirement.new(
    "Need binary '#{commands.join("' or '")}' to be available on the inspected system."
  )
end

#check_retrieve_files_dependencies ⇒ Object 



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# File 'lib/system.rb', line 59

def check_retrieve_files_dependencies
  check_requirement("rsync", "--version")
end

#create_archive(file_list, archive, exclude = []) ⇒ Object

Retrieves files specified in filelist from the remote system and create an archive. To be able to deal with arbitrary filenames we use zero-terminated filelist and the –null option of tar



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# File 'lib/system.rb', line 71

def create_archive(file_list, archive, exclude = [])
  Machinery.logger.info(
    "The following files are packaged in #{archive}: " + Array(file_list).join(", ")
  )
  created = !File.exist?(archive)
  out = File.open(archive, "w")
  begin
    run_command(
      "tar", "--create", "--gzip",
      *exclude.flat_map { |f| ["--exclude", f]},
      "--null", "--files-from=-",
      stdout: out,
      stdin: Array(file_list).join("\0"),
      privileged: true,
      disable_logging: true
    )
  rescue Cheetah::ExecutionFailed => e
    if e.status.exitstatus == 1
      # The tarball has been created successfully but some files were changed
      # on disk while being archived, so we just log the warning and go on
      Machinery.logger.info e.stderr
    else
      raise
    end
  end
  out.close
  File.chmod(0600, archive) if created
end

#has_command?(command) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/system.rb', line 124

def has_command?(command)
  run_command("bash", "-c", "type -P #{command}", stdout: :capture)
  true
rescue Cheetah::ExecutionFailed
  false
end

#managed_files_database ⇒ Object 



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# File 'lib/system.rb', line 139

def managed_files_database
  if @managed_files_database
    return @managed_files_database
  elsif has_command?("rpm")
    @managed_files_database = RpmDatabase.new(self)
  elsif has_command?("dpkg")
    @managed_files_database = DpkgDatabase.new(self)
  else
    raise Machinery::Errors::MissingRequirement.new(
      "Need binary 'rpm' or 'dpkg' to be available on the inspected system."
    )
  end
end

#run_command_with_progress(*command, &callback) ⇒ Object 



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# File 'lib/system.rb', line 120

def run_command_with_progress(*command, &callback)
  run_with_progress(*command, :command, &callback)
end

#run_script(*args) ⇒ Object 



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# File 'lib/system.rb', line 100

def run_script(*args)
  script = File.read(File.join(Machinery::ROOT, "inspect_helpers", args.shift))

  run_command("bash", "-c", script, *args)
end

#run_script_with_progress(*script, &callback) ⇒ Object

Runs the given script on the inspected machine asynchronously and calls the callback method periodically with new output when it occurs.

Example:

count = 0
raw_list = run_script_with_progress("changed_managed_files.sh") do |chunk|
  count += chunk.lines.count
  Machinery::Ui.progress("Found #{count} changed files...")
end



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# File 'lib/system.rb', line 116

def run_script_with_progress(*script, &callback)
  run_with_progress(*script, :script, &callback)
end