Class: Stemcell::Launcher

Inherits:
Object
  • Object
show all
Defined in:
lib/stemcell/launcher.rb

Constant Summary collapse

REQUIRED_OPTIONS = 
[
  'region',
]
REQUIRED_LAUNCH_PARAMETERS = 
[
  'chef_role',
  'chef_environment',
  'chef_data_bag_secret',
  'git_branch',
  'git_key',
  'git_origin',
  'key_name',
  'instance_type',
  'image_id',
  'availability_zone',
  'count'
]
LAUNCH_PARAMETERS = 
[
  'chef_package_source',
  'chef_version',
  'chef_role',
  'chef_environment',
  'chef_data_bag_secret',
  'chef_data_bag_secret_path',
  'cpu_options',
  'git_branch',
  'git_key',
  'git_origin',
  'key_name',
  'instance_type',
  'instance_hostname',
  'instance_domain_name',
  'image_id',
  'availability_zone',
  'vpc_id',
  'subnet',
  'private_ip_address',
  'dedicated_tenancy',
  'associate_public_ip_address',
  'count',
  'min_count',
  'max_count',
  'security_groups',
  'security_group_ids',
  'tags',
  'iam_role',
  'ebs_optimized',
  'termination_protection',
  'block_device_mappings',
  'ephemeral_devices',
  'placement_group'
]
TEMPLATE_PATH = 
'../templates/bootstrap.sh.erb'
LAST_BOOTSTRAP_LINE = 
"Stemcell bootstrap finished successfully!"
MAX_RUNNING_STATE_WAIT_TIME =

seconds

300
RUNNING_STATE_WAIT_SLEEP_TIME =

seconds

5

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}) ⇒ Launcher

Returns a new instance of Launcher.



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# File 'lib/stemcell/launcher.rb', line 69

def initialize(opts={})
  @log = Logger.new(STDOUT)
  @log.level = Logger::INFO unless ENV['DEBUG']
  @log.debug "creating new stemcell object"
  @log.debug "opts are #{opts.inspect}"

  REQUIRED_OPTIONS.each do |opt|
    raise ArgumentError, "missing required option 'region'" unless opts[opt]
  end

  @region = opts['region']
  @vpc_id = opts['vpc_id']
  @ec2_endpoint = opts['ec2_endpoint']
  @aws_access_key = opts['aws_access_key']
  @aws_secret_key = opts['aws_secret_key']
  @aws_session_token = opts['aws_session_token']
  @max_attempts = opts['max_attempts'] || 3
  @bootstrap_template_path = opts['bootstrap_template_path']
  configure_aws_creds_and_region
end

Instance Method Details

#kill(instance_ids, opts = {}) ⇒ Object 



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# File 'lib/stemcell/launcher.rb', line 245

def kill(instance_ids, opts={})
  return if !instance_ids || instance_ids.empty?

  @log.warn "Terminating instances #{instance_ids}"
  ec2.terminate_instances(instance_ids: instance_ids)
  nil # nil == success
rescue Aws::EC2::Errors::InvalidInstanceIDNotFound => e
  raise unless opts[:ignore_not_found]

  invalid_ids = e.message.scan(/i-[a-z0-9]+/)
  instance_ids -= invalid_ids
  retry unless instance_ids.empty? || invalid_ids.empty? # don't retry if we couldn't find any instance ids
end

#launch(opts = {}) ⇒ Object 



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# File 'lib/stemcell/launcher.rb', line 90

def launch(opts={})
  verify_required_options(opts, REQUIRED_LAUNCH_PARAMETERS)

  # attempt to accept keys as file paths
  opts['git_key'] = try_file(opts['git_key'])
  opts['chef_data_bag_secret'] = try_file(opts['chef_data_bag_secret'])

  # generate tags and merge in any that were specified as inputs
  tags = {
    'Name' => "#{opts['chef_role']}-#{opts['chef_environment']}",
    'Group' => "#{opts['chef_role']}-#{opts['chef_environment']}",
    'created_by' => opts.fetch('user', ENV['USER']),
    'stemcell' => VERSION,
  }
  # Short name if we're in production
  tags['Name'] = opts['chef_role'] if opts['chef_environment'] == 'production'
  tags.merge!(opts['tags']) if opts['tags']

  #  Min/max number of instances to launch
  min_count = opts['min_count'] || opts['count']
  max_count = opts['max_count'] || opts['count']

  # generate launch options
  launch_options = {
    :image_id => opts['image_id'],
    :instance_type => opts['instance_type'],
    :key_name => opts['key_name'],
    :min_count => min_count,
    :max_count => max_count,
  }

  # Associate Public IP can only bet set on network_interfaces, and if present
  # security groups and subnet should be set on the interface. VPC-only.
  # Primary network interface
  network_interface = {
    device_index: 0,
  }
  launch_options[:network_interfaces] = [network_interface]

  if opts['security_group_ids'] && !opts['security_group_ids'].empty?
    network_interface[:groups] = opts['security_group_ids']
  end

  if opts['security_groups'] && !opts['security_groups'].empty?
    # convert sg names to sg ids as VPC only accepts ids
    security_group_ids = get_vpc_security_group_ids(@vpc_id, opts['security_groups'])
    network_interface[:groups] ||= []
    network_interface[:groups].concat(security_group_ids)
  end

  launch_options[:placement] = placement = {}
  # specify availability zone (optional)
  if opts['availability_zone']
    placement[:availability_zone] = opts['availability_zone']
  end

  if opts['subnet']
    network_interface[:subnet_id] = opts['subnet']
  end

  if opts['private_ip_address']
    launch_options[:private_ip_address] = opts['private_ip_address']
  end

  if opts['dedicated_tenancy']
    placement[:tenancy] = 'dedicated'
  end

  if opts['associate_public_ip_address']
    network_interface[:associate_public_ip_address] = opts['associate_public_ip_address']
  end

  # specify IAM role (optional)
  if opts['iam_role']
    launch_options[:iam_instance_profile] = {
      name: opts['iam_role']
    }
  end

  # specify placement group (optional)
  if opts['placement_group']
    placement[:group_name] = opts['placement_group']
  end

  # specify an EBS-optimized instance (optional)
  launch_options[:ebs_optimized] = true if opts['ebs_optimized']

  # specify placement group (optional)
  if opts['instance_initiated_shutdown_behavior']
    launch_options[:instance_initiated_shutdown_behavior] =
      opts['instance_initiated_shutdown_behavior']
  end

  # specify raw block device mappings (optional)
  if opts['block_device_mappings']
    launch_options[:block_device_mappings] = opts['block_device_mappings']
  end

  # specify cpu options (optional)
  if opts['cpu_options']
    launch_options[:cpu_options] = opts['cpu_options']
  end

  # specify ephemeral block device mappings (optional)
  if opts['ephemeral_devices']
    launch_options[:block_device_mappings] ||= []
    opts['ephemeral_devices'].each_with_index do |device,i|
      launch_options[:block_device_mappings].push ({
        :device_name => device,
        :virtual_name => "ephemeral#{i}"
      })
    end
  end

  if opts['termination_protection']
    launch_options[:disable_api_termination] = true
  end

  # generate user data script to bootstrap instance, include in launch
  # options UNLESS we have manually set the user-data (ie. for ec2admin)
  launch_options[:user_data] = Base64.encode64(opts.fetch('user_data', render_template(opts)))

  # add tags to launch options so we don't need to make a separate CreateTags call
  launch_options[:tag_specifications] = [{
    resource_type: 'instance',
    tags: tags.map { |k, v| { key: k, value: v } }
  }]

  # launch instances
  instances = do_launch(launch_options)

  # everything from here on out must succeed, or we kill the instances we just launched
  begin
    # wait for aws to report instance stats
    if opts.fetch('wait', true)
      instance_ids = instances.map(&:instance_id)
      @log.info "Waiting up to #{MAX_RUNNING_STATE_WAIT_TIME} seconds for #{instances.count} " \
            "instance(s): (#{instance_ids})"
      instances = wait(instance_ids)
      print_run_info(instances)
      @log.info "launched instances successfully"
    end
  rescue => e
    @log.info "launch failed, killing all launched instances"
    begin
      kill(instances, :ignore_not_found => true)
    rescue => kill_error
      @log.warn "encountered an error during cleanup: #{kill_error.message}"
    end
    raise e
  end

  return instances
end

#render_template(opts = {}) ⇒ Object

this is made public for ec2admin usage



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# File 'lib/stemcell/launcher.rb', line 260

def render_template(opts={})
  template_file_path = @bootstrap_template_path || File.expand_path(TEMPLATE_PATH, __FILE__)
  template_file = File.read(template_file_path)
  erb_template = ERB.new(template_file)
  last_bootstrap_line = LAST_BOOTSTRAP_LINE
  generated_template = erb_template.result(binding)
  @log.debug "generated template is #{generated_template}"
  return generated_template
end