Class: Stemcell::Launcher

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

Constant Summary collapse

REQUIRED_OPTIONS = 
[
  'aws_access_key',
  'aws_secret_key',
  'region'
]
REQUIRED_LAUNCH_PARAMETERS = 
[
  'chef_role',
  'chef_environment',
  'chef_data_bag_secret',
  'git_branch',
  'git_key',
  'git_origin',
  'key_name',
  'instance_type',
  'image_id',
  'security_groups',
  'availability_zone',
  'count'
]
LAUNCH_PARAMETERS = 
[
  'chef_role',
  'chef_environment',
  'chef_data_bag_secret',
  'git_branch',
  'git_key',
  'git_origin',
  'key_name',
  'instance_type',
  'instance_hostname',
  'instance_domain_name',
  'image_id',
  'availability_zone',
  'count',
  'security_groups',
  'tags',
  'iam_role',
  'ebs_optimized',
  'block_device_mappings',
  'ephemeral_devices',
  'placement_group'
]
TEMPLATE_PATH = 
'../templates/bootstrap.sh.erb'
LAST_BOOTSTRAP_LINE = 
"Stemcell bootstrap finished successfully!"

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 58

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 |req|
    raise ArgumentError, "missing required param #{req}" unless opts[req]
    instance_variable_set("@#{req}",opts[req])
  end

  @ec2_url = "ec2.#{@region}.amazonaws.com"
  @timeout = 300
  @start_time = Time.new

  AWS.config({
    :access_key_id     => @aws_access_key,
    :secret_access_key => @aws_secret_key})

  @ec2 = AWS::EC2.new(:ec2_endpoint => @ec2_url)
end

Instance Method Details

#find_instance(id) ⇒ Object 



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# File 'lib/stemcell/launcher.rb', line 165

def find_instance(id)
  return @ec2.instances[id]
end

#kill(instances, opts = {}) ⇒ Object 



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# File 'lib/stemcell/launcher.rb', line 169

def kill(instances,opts={})
  return if instances.nil?
  instances.each do |i|
    begin
      instance = find_instance(i)
      @log.warn "Terminating instance #{instance.instance_id}"
      instance.terminate
    rescue AWS::EC2::Errors::InvalidInstanceID::NotFound => e
      throw e unless opts[:ignore_not_found]
    end
  end
end

#launch(opts = {}) ⇒ Object 



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# File 'lib/stemcell/launcher.rb', line 81

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 specefied 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,
  }
  tags.merge!(opts['tags']) if opts['tags']

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

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

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

  # specify placement group (optional)
  if opts['placement_group']
    launch_options[:placement] = {
      :group_name => opts['placement_group'],
    }
  end

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

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

  #

  # 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] = opts.fetch('user_data', render_template(opts))

  # launch instances
  instances = do_launch(launch_options)

  # set tags on all instances launched
  set_tags(instances, tags)
  @log.info "sent ec2 api requests successfully"

  # wait for aws to report instance stats
  if opts.fetch('wait', true)
    wait(instances)
    print_run_info(instances)
    @log.info "launched instances successfully"
  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 183

def render_template(opts={})
  template_file_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 "genereated template is #{generated_template}"
  return generated_template
end