Class: ContainerManagerAdapter::Lxc

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

Overview

Container adapter for LXC. Encapsulates all LXC specific command line wrapping

Instance Method Summary collapse

Instance Method Details

#container(name) ⇒ Hash

Returns information for a single container

Parameters:

  • The container name

Returns:

  • Hash with information about the container



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 128

def container(name)
  data = {}

  data[:name] = name
  data[:state] = translate_state(state(name))
  data[:ip_address] = ip_addr(name)
  data[:cpu_cores] = assigned_cpu_cores(name).count
  data[:memory_limit_bytes] = memory_limit(name).to_i
  data[:memory_usage_bytes] = memory_usage(name).to_i
  data[:disk_space_gb] = 0
  data[:disk_usage_gb] = 0
  data[:container_type] = 'lxc'

  data
end

#containers ⇒ Array

Lists all available containers

Returns:



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 37

def containers
  container_list = []

  self.container_names.each do |item|
    container_list << container(item)
  end

  container_list
end

#create_container(name, ip_address, disk_size_gb, memory_limit_mb, cpu_core_count, template) ⇒ String

Creates a container with the given parameters

Parameters:

  • The container name

  • A valid IPv4 address

  • The disk size in GB

  • The memory limit in MB

  • Amount of Vcores to assign. 0 if no limit should be set

  • Name of the template to use

Returns:

  • CLI output

Raises:



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 156

def create_container(name, ip_address, disk_size_gb, memory_limit_mb, cpu_core_count, template)
  output = ''

  begin
    if cpu_core_count != 0
      cpuset = self.generate_cpu_set(cpu_core_count, ResourceManager.new('linux'))
    end

    if false == $lxc_cmd_create.has_key?(template)
      raise ArgumentError, "template does not exist"
    end

    create_result = Open3.capture3($lxc_cmd_create[template].gsub('[name]', name))

    output += create_result[0]
    output += create_result[1]

    config_path = $lxc_container_config_path.gsub('[name]', name)

    open(config_path, 'a') do |f|
      f << "lxc.network.ipv4=#{ip_address}/#{$lxc_ip_netmask}\n"
      f << "lxc.start.auto=1\n"
      f << "lxc.start.delay=5\n"

      if cpu_core_count.to_i != 0
        f << "lxc.cgroup.cpuset.cpus=#{cpuset}\n"
      end

      if memory_limit_mb.to_i != 0
        f << "lxc.cgroup.memory.limit_in_bytes=#{memory_limit_mb.to_s}M\n"
      end
    end

    $logger.info("creation of container " + name + " successful")
    return output.strip
  rescue => e
    $logger.warn("container " + name + " could not be created, rolling back...")

    # rollback
    delete(name) if exist?(name)

    output += e.message
    raise RuntimeError, output.strip
  end
end

#delete(name) ⇒ String

Deletes a container with the given name

Parameters:

  • The container name

Returns:

  • CLI output

Raises:



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 111

def delete(name)
  res = Open3.capture3($lxc_cmd_destroy.gsub('[name]', name))

  if res[1].empty? && res[2].exitstatus == 0
    $logger.info("container " + name + " successfully deleted")
    return res[0].strip
  end

  $logger.warn("container" + name + " could not be deleted")
  raise RuntimeError, res[1].strip
end

#exist?(name) ⇒ Boolean

Checks if a container with the given name exists

Parameters:

  • The container name

Returns:

  • Existing/not existing



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 207

def exist?(name)
  self.container_names().include?(name)
end

#free_cpu_core_count(resman) ⇒ Integer

Returns the amount of free cpu cores

Parameters:

  • A ResourceManager instance

Returns:

  • The amount of free cpu cores



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 216

def free_cpu_core_count(resman)
  self.free_cpu_cores(resman).count
end

#kill(name) ⇒ String

Kills a container with the given name

Parameters:

  • The container name

Returns:

  • CLI output

Raises:



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 92

def kill(name)
  res = Open3.capture3($lxc_cmd_kill.gsub('[name]', name))

  if res[1].empty? && res[2].exitstatus == 0
    $logger.info("container " + name + " successfully killed")
    return res[0].strip
  end

  $logger.warn("container " + name + " could not be killed")
  raise RuntimeError, res[1].strip
end

#start(name) ⇒ String

Starts a container with the given name

Parameters:

  • The container name

Returns:

  • CLI output

Raises:



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 54

def start(name)
  res = Open3.capture3($lxc_cmd_start.gsub('[name]', name))

  if res[1].empty? && res[2].exitstatus == 0
    $logger.info("container " + name + " successfully started")
    return res[0].strip
  end

  $logger.warn("container " + name + " could not be started")
  raise RuntimeError, res[1].strip
end

#stop(name) ⇒ String

Stops a container with the given name

Parameters:

  • The container name

Returns:

  • CLI output

Raises:



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 73

def stop(name)
  res = Open3.capture3($lxc_cmd_stop.gsub('[name]', name))

  if res[1].empty? && res[2].exitstatus == 0
    $logger.info("container " + name + " successfully stopped")
    return res[0].strip
  end

  $logger.warn("container " + name + " could not be stopped")
  raise RuntimeError, res[1].strip
end

#supported_templates ⇒ Hash

Returns a list of supported templates

Returns:

  • List of supported templates



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# File 'lib/wf_node_api/container_manager_adapter/lxc.rb', line 223

def supported_templates
  $lxc_cmd_create.keys
end