Class: CloudMaker::EC2

Inherits:
Object
  • Object
show all
Defined in:
lib/cloud_maker/ec2.rb

Constant Summary collapse

CLOUD_MAKER_CONFIG =

Public: A CloudMaker::Config hash that describes the config properties EC2 relies on.

{
  'cloud-maker' => {
    'ami' => {
      'required' => true,
      'description' => "The Amazon AMI ID for the instance."
    },
    'instance_type' => {
      'required' => true,
      'description' => "The Amazon instance type, eg. m1.small."
    },
    'availability_zone' => {
      'required' => true,
      'description' => "The Amazon availability zone, eg. us-east-1a"
    },
    'key_pair' => {
      'default' => "",
      'description' => "The name of an Amazon key pair, so you can actually login to the instance."
    },
    'elastic_ip' => {
      'default' => '',
      'description' => "An elastic IP address you control that you would like to associate to the instance."
    },
    'security_group' => {
      'default' => 'default',
      'required' => true,
      'description' => 'The Amazon EC2 security group to launch the instance with.'
    },
    'iam_role' => {
      'default' => '',
      'description' => 'The IAM instance profile name or ARN you would like to use.'
    },
    'cname' => {
      'default' => '',
      'description' => "A dns entry you would like to CNAME to this instance."
    },
    'block_device_mappings' => {
      'description' => "A hash of block devices mappings. ie. { /dev/sda1 => { volume_size => <value_in_GB>, snapshot_id => <id>, delete_on_termination => <boolean> } }"
    },
    'elb' => {
      'default' => '',
      'description' => "The load balancer to use."
    }
  }
}
BUCKET_TAG =

Public: The name of the tag that will be used to find the name of an s3 bucket for archiving/information retrieval

's3_archive_bucket'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ EC2

Public: Creates a new EC2 instance

cloud_maker_config - A CloudMaker::Config object describing the instance

to be managed.

options - S3 configuration options

:aws_access_key_id     - (required) The AWS access key
:aws_secret_access_key - (required) The AWS secret

Returns a new CloudMaker::EC2 instance Raises RuntimeError if any of the required options are not specified



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# File 'lib/cloud_maker/ec2.rb', line 69

def initialize(options)
  required_keys = [:aws_access_key_id, :aws_secret_access_key]
  unless (required_keys - options.keys).empty?
    raise RuntimeError.new("Instantiated #{self.class} without required attributes: #{required_keys - options.keys}.")
  end

  self.aws_access_key_id = options[:aws_access_key_id]
  self.aws_secret_access_key = options[:aws_secret_access_key]

  self.ec2 = AWS::EC2.new(:access_key_id => self.aws_access_key_id, :secret_access_key => self.aws_secret_access_key)
end

Instance Attribute Details

#aws_access_key_id ⇒ Object

Public: Gets/Sets the AWS secret.



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# File 'lib/cloud_maker/ec2.rb', line 6

def aws_access_key_id
  @aws_access_key_id
end

#aws_secret_access_key ⇒ Object

Public: Gets/Sets the AWS access key.



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# File 'lib/cloud_maker/ec2.rb', line 4

def aws_secret_access_key
  @aws_secret_access_key
end

#ec2 ⇒ Object

Internal: Gets/Sets the AWS::EC2 instance.



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# File 'lib/cloud_maker/ec2.rb', line 8

def ec2
  @ec2
end

Class Method Details

.instance_to_hash(instance) ⇒ Object

Public: Generates a hash of properties from an AWS::EC2 instance

Returns a hash of properties for the instance.



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# File 'lib/cloud_maker/ec2.rb', line 242

def instance_to_hash(instance)
  {
    :instance_id => instance.id,
    :ami => instance.image_id,
    :api_termination_disabled => instance.api_termination_disabled?,
    :dns_name => instance.dns_name,
    :ip_address => instance.ip_address,
    :private_ip_address => instance.private_ip_address,
    :key_name => instance.key_name,
    :owner_id => instance.owner_id,
    :status => instance.status,
    :tags => instance.tags.inject({}) {|hash, tag| hash[tag.first] = tag.last;hash}
  }
end

Instance Method Details

#find_instance(instance_id) ⇒ Object

Internal: Find the instance object for an instance ID regardless of what region the instance is in. It looks in the default region (us-east-1) first and then looks in all regions if it’s not there.

Returns nil or an AWS::EC2::Instance



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# File 'lib/cloud_maker/ec2.rb', line 207

def find_instance(instance_id)
  # Check the default region first
  return ec2.instances[instance_id] if ec2.instances[instance_id].exists?

  # If we don't find it there look in every region
  instance = nil
  ec2.regions.each do |region|
    if region.instances[instance_id].exists?
      instance = region.instances[instance_id]
      break
    end
  end

  instance
end

#find_region(availability_zone) ⇒ Object

Internal: Find the region object for a given availability zone. Currently works based on amazon naming conventions and will break if they change.

Returns an AWS::EC2::Region Raises a RuntimeError if the region doesn’t exist



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# File 'lib/cloud_maker/ec2.rb', line 229

def find_region(availability_zone)
  region_name = availability_zone.gsub(/(\d)\w$/, '\1')
  if ec2.regions[region_name].exists?
    ec2.regions[region_name]
  else
    raise RuntimeError.new("The region #{region_name} doesn't exist - region name generated from availability_zone: #{availability_zone}.")
  end
end

#info(instance_id) ⇒ Object

Public: Fetch archived information about an instance

Returns a hash of information about the instance as it was launched



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# File 'lib/cloud_maker/ec2.rb', line 84

def info(instance_id)
  instance = find_instance(instance_id)
  bucket = instance.tags[BUCKET_TAG]

  archiver = S3Archiver.new(
    :instance_id => instance_id,
    :aws_access_key_id => self.aws_access_key_id,
    :aws_secret_access_key => self.aws_secret_access_key,
    :bucket_name => bucket
  )

  archiver.load_archive
end

#launch(cloud_maker_config) ⇒ Object

Public: Launches a new EC2 instance, associates any specified elastic IPS with it, adds any specified tags, and archives the launch details to S3.

Returns an AWS::EC2 object for the launched instance.



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# File 'lib/cloud_maker/ec2.rb', line 109

def launch(cloud_maker_config)
  user_data = cloud_maker_config.to_user_data

  if !cloud_maker_config['availability_zone'].nil? && !cloud_maker_config['availability_zone'].empty?
    region = find_region(cloud_maker_config['availability_zone'])
  else
    region = ec2 # .instances.create will just put things in the default region
  end

  config = {
    :image_id => cloud_maker_config['ami'],
    :iam_instance_profile => cloud_maker_config['iam_role'],
    :security_groups => cloud_maker_config['security_group'],
    :instance_type => cloud_maker_config['instance_type'],
    :key_name => cloud_maker_config['key_pair'],
    :availability_zone => cloud_maker_config['availability_zone'],
    :user_data => user_data
  }
  config[:block_device_mappings] = cloud_maker_config['block_device_mappings'] if cloud_maker_config['block_device_mappings']

  instance = region.instances.create(config)

  begin
    if cloud_maker_config['tags']
      # we can only set tags to be strings so make sure we convert all of our tags
      # to strings
      string_tags = cloud_maker_config['tags'].inject({}) do |hash, pair|
        hash[pair[0]] = pair[1].to_s
        hash
      end
      instance.tags.set(string_tags)
    end
  rescue AWS::EC2::Errors::InvalidInstanceID::NotFound => e
    retries ||= 0
    if retries < 5
      sleep(2**retries)
      retries += 1
      retry
    end
  end

  if cloud_maker_config.elastic_ip? || cloud_maker_config.cname?
    while instance.status == :pending
      #wait
    end
    instance.associate_elastic_ip(cloud_maker_config["elastic_ip"]) if cloud_maker_config.elastic_ip?

    if cloud_maker_config.cname?
      r53 = AWS::Route53::Client.new(:access_key_id => self.aws_access_key_id, :secret_access_key => self.aws_secret_access_key)

      zone = r53.list_hosted_zones[:hosted_zones].select {|zone|
        cloud_maker_config['cname'] + '.' =~ /#{Regexp.escape(zone[:name])}$/
      }.first

      r53.change_resource_record_sets(
        :hosted_zone_id => zone[:id],
        :change_batch => {
          :comment => "CloudMaker initialization of #{instance.instance_id}.", :changes => [{
            :action => "CREATE", :resource_record_set => {
              :name => cloud_maker_config['cname'],
              :type => 'CNAME',
              :ttl => 60,
              :resource_records => [{:value => instance.dns_name}]
            }
          }]
        }
      )
    end
  end

  if cloud_maker_config.elb?
    while instance.status == :pending
      #wait
    end
    elb_interface = ElbInterface.new(
      :instance => instance,
      :aws_access_key_id => self.aws_access_key_id,
      :aws_secret_access_key => self.aws_secret_access_key,
      :elb_name => cloud_maker_config["elb"]
    ).attach
  end
  
  archiver = S3Archiver.new(
    :instance_id => instance.id,
    :aws_access_key_id => self.aws_access_key_id,
    :aws_secret_access_key => self.aws_secret_access_key,
    :bucket_name => cloud_maker_config["tags"][BUCKET_TAG]
  )
  archiver.store_archive(cloud_maker_config, self.class.instance_to_hash(instance))

  instance
end

#terminate(instance_id) ⇒ Object

Public: Terminates the specified EC2 instance.

Returns nothing.



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# File 'lib/cloud_maker/ec2.rb', line 101

def terminate(instance_id)
  find_instance(instance_id).terminate
end