Class: LXC::Container

Inherits:
Object
  • Object
show all
Defined in:
lib/lxc/container.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ LXC::Container

Initialize a new LXC::Container instance

Parameters:

  • name (String) —

    container name



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# File 'lib/lxc/container.rb', line 10

def initialize(name)
  @name = name
end

Instance Attribute Details

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/lxc/container.rb', line 3

def name
  @name
end

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/lxc/container.rb', line 5

def pid
  @pid
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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# File 'lib/lxc/container.rb', line 4

def state
  @state
end

Instance Method Details

#clone_from(source) ⇒ Boolean

Create a new container from an existing container

Parameters:

  • source (String) —

    name of existing container

Returns:

  • (Boolean)

Raises:



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# File 'lib/lxc/container.rb', line 187

def clone_from(source)
  raise ContainerError, "Container already exists." if exists?
  unless self.class.new(source).exists?
    raise ContainerError, "Source container does not exist."
  end

  LXC.run('clone', '-o', source, '-n', name)
  exists?
end

#clone_to(target) ⇒ LXC::Container

Clone to a new container from self

Parameters:

  • target (String) —

    name of new container

Returns:

Raises:



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# File 'lib/lxc/container.rb', line 174

def clone_to(target)
  raise ContainerError, "Container does not exist." unless exists?
  if self.class.new(target).exists?
    raise ContainerError, "New container already exists."
  end

  LXC.run('clone', '-o', name, '-n', target)
  self.class.new target
end

#cpu_shares ⇒ Integer

Get container cpu shares

Returns:

  • (Integer) 


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# File 'lib/lxc/container.rb', line 113

def cpu_shares
  result = run('cgroup', "cpu.shares").strip
  result.empty? ? nil : result.to_i
end

#cpu_usage ⇒ Float

Get container cpu usage in seconds

Returns:

  • (Float) 


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# File 'lib/lxc/container.rb', line 120

def cpu_usage
  result = run('cgroup', "cpuacct.usage").strip
  result.empty? ? nil : Float('%.4f' % (result.to_i / 1E9))
end

#create(path) ⇒ Boolean

Create a new container

Parameters:

  • path (String) —

    path to container config file or [Hash] options

Returns:

  • (Boolean)

Raises:



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# File 'lib/lxc/container.rb', line 138

def create(path)
  raise ContainerError, "Container already exists." if exists?

  if path.is_a?(Hash)
    args = "-n #{name}"

    if !!path[:config_file]
      unless File.exists?(path[:config_file])
        raise ArgumentError, "File #{path[:config_file]} does not exist."
      end
      args += " -f #{path[:config_file]}"
    end

    if !!path[:template]
      template_path = "/usr/lib/lxc/templates/lxc-#{path[:template]}"
      unless File.exists?(template_path)
        raise ArgumentError, "Template #{path[:template]} does not exist."
      end
      args += " -t #{path[:template]} "
    end

    args += " -B #{path[:backingstore]}" if !!path[:backingstore]
    args += " -- #{path[:template_options].join(' ')}".strip if !!path[:template_options]

    LXC.run('create', args)
    exists?
  else
    raise ArgumentError, "File #{path} does not exist." unless File.exists?(path)
    LXC.run('create', '-n', name, '-f', path)
    exists?
  end
end

#destroy(force = false) ⇒ Boolean

Destroy the container If container is running and force parameter is true it will be stopped first. Otherwise it will raise exception.

Parameters:

  • force (Boolean) (defaults to: false) —

    force destruction

Returns:

  • (Boolean) —

    true if container was destroyed

Raises:



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# File 'lib/lxc/container.rb', line 204

def destroy(force=false)
  raise ContainerError, "Container does not exist." unless exists?

  if running?
    if force
      # This will force stop and destroy container automatically
      run('destroy', '-f')
    else
      raise ContainerError, "Container is running. Stop it first or use force=true"
    end
  else
    run('destroy')
  end  

  !exists?
end

#exists? ⇒ Boolean

Check if container exists

Returns:

  • (Boolean) 


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# File 'lib/lxc/container.rb', line 32

def exists?
  LXC.run('ls').split("\n").uniq.include?(name)
end

#freeze ⇒ Hash

Freeze container

Returns:

  • (Hash) —

    container status hash



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# File 'lib/lxc/container.rb', line 77

def freeze
  run('freeze')
  status
end

#frozen? ⇒ Boolean

Check if container is frozen

Returns:

  • (Boolean) 


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# File 'lib/lxc/container.rb', line 44

def frozen?
  status[:state] == 'FROZEN'
end

#memory_limit ⇒ Integer

Get container memory limit in bytes

Returns:

  • (Integer) 


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# File 'lib/lxc/container.rb', line 107

def memory_limit
  run('cgroup', 'memory.limit_in_bytes').strip.to_i
end

#memory_usage ⇒ Integer

Get container memory usage in bytes

Returns:

  • (Integer) 


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# File 'lib/lxc/container.rb', line 101

def memory_usage
  run('cgroup', 'memory.usage_in_bytes').strip.to_i
end

#processes ⇒ Array

Get container processes

Returns:

  • (Array) —

    list of all processes

Raises:



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# File 'lib/lxc/container.rb', line 127

def processes
  raise ContainerError, "Container is not running" if !running?

  str = run('ps', '--', '-eo pid,user,%cpu,%mem,args').strip
  lines = str.split("\n") ; lines.delete_at(0)
  lines.map { |l| parse_process_line(l) }
end

#restart ⇒ Hash

Restart container

Returns:

  • (Hash) —

    container status hash



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# File 'lib/lxc/container.rb', line 70

def restart
  stop
  start
end

#running? ⇒ Boolean

Check if container is running

Returns:

  • (Boolean) 


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# File 'lib/lxc/container.rb', line 38

def running?
  status[:state] == 'RUNNING'
end

#start ⇒ Hash

Start container

Returns:

  • (Hash) —

    container status hash



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# File 'lib/lxc/container.rb', line 56

def start
  run('start', '-d')
  status
end

#status ⇒ Hash

Get current status of container

Returns:

  • (Hash) —

    hash with :state and :pid attributes



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# File 'lib/lxc/container.rb', line 23

def status
  str    = LXC.run('info', '-n', name)
  @state = str.scan(/^state:\s+([\w]+)$/).flatten.first
  @pid   = str.scan(/^pid:\s+(-?[\d]+)$/).flatten.first
  {:state => @state, :pid => @pid}
end

#stop ⇒ Hash

Stop container

Returns:

  • (Hash) —

    container status hash



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# File 'lib/lxc/container.rb', line 63

def stop
  run('stop')
  status
end

#stopped? ⇒ Boolean

Check if container is stopped?

Returns:

  • (Boolean) 


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# File 'lib/lxc/container.rb', line 50

def stopped?
  exists? && status[:state] == 'STOPPED'
end

#to_hash ⇒ Hash

Get container attributes hash

Returns:

  • (Hash) 


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# File 'lib/lxc/container.rb', line 16

def to_hash
  status
  {'name' => name, 'state' => state, 'pid' => pid}
end

#unfreeze ⇒ Hash

Unfreeze container

Returns:

  • (Hash) —

    container status hash



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# File 'lib/lxc/container.rb', line 84

def unfreeze
  run('unfreeze')
  status
end

#wait(state) ⇒ Object

Wait for container to change status

Parameters:

  • state (String) —

    state name



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# File 'lib/lxc/container.rb', line 91

def wait(state)
  if !LXC::Shell.valid_state?(state)
    raise ArgumentError, "Invalid container state: #{state}"
  end

  run('wait', '-s', state)
end