Class: Kplay::Pod

Inherits:
Object
  • Object
show all
Defined in:
lib/kplay/pod.rb

Overview

Pod represents a pod associated with a folder on a host machine

Constant Summary collapse

DEFAULT_SHM_VOLUME_NAME = 
"pod-shm-volume"
DEFAULT_SHM_VOLUME_PATH = 
"/dev/shm"

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path_host, config = nil, options = {}) ⇒ Pod

Creates a Pod from a path on host

Parameters:

  • path_host (String)
  • config (Config) (defaults to: nil) —

    local pod configuration options

  • options (Hash) (defaults to: {}) —

    command execution options



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# File 'lib/kplay/pod.rb', line 21

def initialize(path_host, config = nil, options = {})
  @path_host = path_host
  @path_vm = Kplay::Minikube.host_path_in_vm(path_host)
  @name = File.basename(path_host)
  @config = config ? config : Kplay::Config.global
  @config.expand_templates!(
    name: name,
    path_host: path_host,
    path_vm: path_vm
  )
  @options = options
  @volume_name = name + '-volume'
end

Instance Attribute Details

#config ⇒ Object (readonly)

Returns the value of attribute config.



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# File 'lib/kplay/pod.rb', line 13

def config
  @config
end

#mount_path ⇒ Object (readonly)

Returns the value of attribute mount_path.



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# File 'lib/kplay/pod.rb', line 13

def mount_path
  @mount_path
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/kplay/pod.rb', line 13

def name
  @name
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/kplay/pod.rb', line 13

def options
  @options
end

#path_host ⇒ Object (readonly)

Returns the value of attribute path_host.



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# File 'lib/kplay/pod.rb', line 13

def path_host
  @path_host
end

#path_vm ⇒ Object (readonly)

Returns the value of attribute path_vm.



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# File 'lib/kplay/pod.rb', line 13

def path_vm
  @path_vm
end

#volume_name ⇒ Object (readonly)

Returns the value of attribute volume_name.



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# File 'lib/kplay/pod.rb', line 13

def volume_name
  @volume_name
end

Instance Method Details

#configuration ⇒ Hash

Kubernetes configuration to run this pod

Returns:

  • (Hash) 


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# File 'lib/kplay/pod.rb', line 39

def configuration
  host_aliases = config[:etc_hosts].map do |host|
    ip, *hostnames = host.strip.split(' ')
    { 'ip' => ip, 'hostnames' => hostnames }
  end
  c = {
    'apiVersion' => 'v1',
    'kind' => 'Pod',
    'metadata' => { 'name' => name },
    'spec' => {
      'hostAliases' => host_aliases,
      'containers' => [
        {
          'name' => name,
          'image' => options[:image] || config[:image],
          'imagePullPolicy' => 'IfNotPresent',
          'env' => [
            # { 'name' => ..., 'value' => ... }
          ],
          'volumeMounts' => [
            { 'mountPath' => config[:mount_path], 'name' => volume_name },
            { 'mountPath' => DEFAULT_SHM_VOLUME_PATH, 'name' => DEFAULT_SHM_VOLUME_NAME },
            # <-- ssh forwarding socket should be mounted a CONTAINER here
          ]
        }
      ],
      'volumes' => [
        {
          'name' => volume_name,
          'hostPath' => { 'path' => path_vm.to_s }
        },
        {
          'name' => DEFAULT_SHM_VOLUME_NAME,
          'emptyDir' => {
            'medium' => 'Memory',
            'sizeLimit' => config[:shm_size]
          }
        }
        # <-- ssh forwarding socket in VM mounted here
      ]
    }
  }
  # add custom volumes
  config[:volumes].each_with_index do |volume_def, i|
    v_from, v_to = volume_def.split(':')
    v_from = Kplay::Minikube.host_path_in_vm(Pathname.new(v_from).expand_path)
    v_to   = Pathname.new(v_to) # do not expand path locally
    name = 'volume-' + i.to_s
    c['spec']['containers'].first['volumeMounts'] <<
      { 'name' => name, 'mountPath' => v_to.to_s }
    c['spec']['volumes'] <<
      { 'name' => name, 'hostPath' => { 'path' => v_from.to_s } }
  end
  c
end

#configuration_yaml ⇒ Object

Returns Kubernetes pod configuration in YAML



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# File 'lib/kplay/pod.rb', line 97

def configuration_yaml
  configuration.to_yaml
end

#shell ⇒ Object

Runs a shell session inside the pod



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# File 'lib/kplay/pod.rb', line 121

def shell
  Kplay.sh(
    ['kubectl', 'exec', '-ti', name, '--', config[:shell], *config[:shell_args]],
    tty: true,
    echo: options[:verbose]
  )
end

#start! ⇒ Object

Runs the pod in Kubernetes cluster



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# File 'lib/kplay/pod.rb', line 103

def start!
  with_configuration_file do |conf_file|
    Kplay.sh ['kubectl', 'apply', '-f', conf_file.path], echo: options[:verbose]
  end
  sleep 1
end

#stop! ⇒ Object

Stops the pod



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# File 'lib/kplay/pod.rb', line 112

def stop!
  Kplay.sh(
    ['kubectl', 'delete', 'pod', name, "--grace-period=#{config[:stop_grace_period]}"],
    echo: options[:verbose]
  )
end

#temp_configuration_file ⇒ Tempfile

Creates a temporary configuration file and returns it

Returns:

  • (Tempfile) 


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# File 'lib/kplay/pod.rb', line 133

def temp_configuration_file
  @temp_configuration_file ||= begin
    tempfile = Tempfile.new("kplay-#{name}")
    tempfile.write(configuration_yaml)
    tempfile.close
    tempfile
  end
end

#with_configuration_file(&_block) ⇒ Object

Creates a temporary configuration file for the pod, yields it to the given block and then deletes it.



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# File 'lib/kplay/pod.rb', line 146

def with_configuration_file(&_block)
  yield temp_configuration_file
ensure
  temp_configuration_file.unlink
  @temp_configuration_file = nil
end