class AWS::EC2

Provides an expressive, object-oriented interface to Amazon EC2.

## Credentials

You can setup default credentials for all AWS services via AWS.config:

AWS.config(
  :access_key_id => 'YOUR_ACCESS_KEY_ID',
  :secret_access_key => 'YOUR_SECRET_ACCESS_KEY')

Or you can set them directly on the EC2 interface:

ec2 = AWS::EC2.new(
  :access_key_id => 'YOUR_ACCESS_KEY_ID',
  :secret_access_key => 'YOUR_SECRET_ACCESS_KEY')

## Instances

EC2 uses instances to run your software.

To run an instance:

ec2.instances.create(:image_id => "ami-8c1fece5")

To get an instance by ID:

i = ec2.instances["i-12345678"]
i.exists?

To get a list of instances:

ec2.instances.inject({}) { |m, i| m[i.id] = i.status; m }
# => { "i-12345678" => :running, "i-87654321" => :shutting_down }

## Security Groups

A security group is a named collection of access rules. These access rules specify which ingress (i.e., incoming) network traffic should be delivered to your instance. All other ingress traffic will be discarded.

To create a security group:

websvr = ec2.security_groups.create('webservers')

Then you can add ingress authorizations. In the following example we add a rule that allows web traffic from the entire internet.

# web traffic
websvr.authorize_ingress(:tcp, 80)

You can also specify a port range. Here we are opening FTP traffic:

# ftp traffic
websvr.authorize_ingress(:tcp, 20..21)

If you want to limit an authorization to a particular CIDR IP address or list of address, just add them to the authorize_ingress call.

# ssh access
websrvr.authorize_ingress(:tcp, 22, '1.1.1.1/0', '2.2.2.2/0')

You can also provide another security group instead of CIDR IP addresses. This allows incoming traffic from EC2 instances in the given security group(s).

# get two existing security groups
dbsvrs = ec2.security_groups.filter('group-name', 'db-servers').first
websvrs = ec2.security_groups.filter('group-name', 'web-servers').first

# allow instances in the 'web-servers' security group to connect
# to instances in the 'db-servers' security group over tcp port 3306
dbsvrs.authorize_ingress(:tcp, 3306, websvrs)

There are a few handy shortcuts for allowing pings:

wbsvrs.allow_ping

Just like with authorize_ingress you can pass a security group or a list of CIDR IP addresses to allow ping to limit where you can ping from.

You can also use the same parameters from the examples above to {SecurityGroup#revoke_ingress} and {SecurityGroup#disallow_ping}.

You can specify other protocols than ‘:tcp`, like :udp and :icmp.

## Elastic IPs

You can allocate up to 5 elastic IP addresses for each account. You can associate those elastic IP addresses with EC2 instances:

instance = ec2.instances['i-12345678']
ip = ec2.elastic_ips.allocate

instance.ip_address                # 1.1.1.1
ip.ip_address                      # 2.2.2.2

instance.associate_elastic_ip(ip)
instance.ip_address                # 2.2.2.2

instance.disassociate_elastic_ip
instance.ip_address                # 1.1.1.1

When you are done with an elastic IP address you should release it. In the following example we release all elastic IP addresses that are not currently associated with an instance:

ec2.elastic_ips.select{|ip| !ip.associated? }.each(&:release)

## Key Pairs

Public Amazon Machine Image (AMI) instances have no password, and you need a public/private key pair to log in to them. The public key half of this pair is embedded in your instance, allowing you to use the private key to log in securely without a password.

You can generate a key pair yourself and then send the public part to EC2 using {KeyPairCollection#import}. For example:

key_pair = ec2.key_pairs.import("mykey", File.read("~/.ssh/identity.pub"))

You can also ask EC2 to generate a key pair for you. For example:

key_pair = ec2.key_pairs.create("mykey")
File.open("~/.ssh/ec2", "wb") do |f|
  f.write(key_pair.private_key)
end

## Filtering and Tagging

Any of the collections in the interface may be filtered by a number of different parameters. For example, to get all the windows images owned by amazon where the description includes the string “linux”, you can do this:

ec2.images.with_owner("amazon").
  filter("platform", "windows").
  filter("description", "*linux*")

Similarly, you can tag images, instances, security groups, snapshots, and volumes with free-form key-value metadata and filter on that metadata. For example:

ec2.images["ami-123"].tags << "myapp"
ec2.images.tagged("myapp")             # will include ami-123

## Regions

Amazon has data centers in different areas of the world (e.g., North America, Europe, Asia, etc.). Correspondingly, EC2 is available to use in different Regions. By launching instances in separate Regions, you can design your application to be closer to specific customers or to meet legal or other requirements. Prices for Amazon EC2 usage vary by Region (for more information about pricing by Region, go to the [Amazon EC2 Pricing page](aws.amazon.com/ec2/pricing)). You can use the Ruby SDK to see which regions are available for your account:

ec2.regions.map(&:name)            # => ["us-east-1", ...]

The default region is ‘us-east-1`; you can access other regions like this:

ec2 = AWS::EC2.new(:region => "us-west-1")
ec2.instances.create(:image_id => 'ami-3bc9997e')

## Availability Zones

Each Region contains multiple distinct locations called Availability Zones. Each Availability Zone is engineered to be isolated from failures in other Availability zones and to provide inexpensive, low-latency network connectivity to other zones in the same Region. By launching instances in separate Availability Zones, you can protect your applications from the failure of a single location.

You can use the {#availability_zones} collection to get information about the available zones available to your account. For example:

ec2.availability_zones.map(&:name)   # => ["us-east-1a", ...]

## Images

An Amazon Machine Image (AMI) contains all information necessary to boot instances of your software. For example, an AMI might contain all the software to act as a web server (e.g., Linux, Apache, and your web site) or it might contain all the software to act as a Hadoop node (e.g., Linux, Hadoop, and a custom application).

You can use the {#images} collection to get information about the images available to your account. For example:

ec2.images.with_owner("amazon").map(&:name)

You can also use the images collection to create new images:

ec2.images.create(
 :image_location => "mybucket/manifest.xml",
 :name => "my-image")

@!attribute [r] client

@return [Client] the low-level EC2 client object

Public Instance Methods

availability_zones() click to toggle source

@return [AvailabilityZoneCollection] A collection representing

all EC2 availability zones.
# File lib/aws/ec2.rb, line 328
def availability_zones
  AvailabilityZoneCollection.new(:config => config)
end
customer_gateways() click to toggle source

@return [CustomerGatewayCollection] Returns a collection that

represents all of the customer gateways for this account.
# File lib/aws/ec2.rb, line 400
def customer_gateways
  CustomerGatewayCollection.new(:config => config)
end
dhcp_options() click to toggle source

@return [DHCPOptionsCollection] Returns a collection that

represents all of the dhcp options for this account.
# File lib/aws/ec2.rb, line 412
def dhcp_options
  DHCPOptionsCollection.new(:config => config)
end
elastic_ips() click to toggle source

@return [ElasticIpCollection] A collection representing all

elastic IP addresses for this account.
# File lib/aws/ec2.rb, line 305
def elastic_ips
  ElasticIpCollection.new(:config => config)
end
export_tasks() click to toggle source

@return [ExportTaskCollection]

# File lib/aws/ec2.rb, line 423
def export_tasks
  ExportTaskCollection.new(:config => config)
end
images() click to toggle source

@return [ImageCollection] A collection representing

all Amazon Machine Images available to your account.
# File lib/aws/ec2.rb, line 334
def images
  ImageCollection.new(:config => config)
end
instances() click to toggle source

@return [InstanceCollection] A collection representing all instances

# File lib/aws/ec2.rb, line 293
def instances
  InstanceCollection.new(:config => config)
end
internet_gateways() click to toggle source

@return [InternetGatewayCollection] Returns a collection that

represents all of the internet gateways for this account.
# File lib/aws/ec2.rb, line 394
def internet_gateways
  InternetGatewayCollection.new(:config => config)
end
key_pairs() click to toggle source

@return [KeyPairCollection] A collection representing all key pairs.

# File lib/aws/ec2.rb, line 310
def key_pairs
  KeyPairCollection.new(:config => config)
end
network_acls() click to toggle source

@return [NetworkACLCollection] Returns a collection that represents

all of the network ACLs for this account.
# File lib/aws/ec2.rb, line 376
def network_acls
  NetworkACLCollection.new(:config => config)
end
network_interfaces() click to toggle source

@return [NetworkInterfaceCollection] Returns a collection that

represents all of the network interfaces for this account.
# File lib/aws/ec2.rb, line 388
def network_interfaces
  NetworkInterfaceCollection.new(:config => config)
end
regions() click to toggle source

@return [RegionCollection] A collection representing all EC2

regions.
# File lib/aws/ec2.rb, line 322
def regions
  RegionCollection.new(:config => config)
end
reserved_instances() click to toggle source

@return [ReservedInstancesCollection] A collection representing all

purchased reserved instance offerings.
# File lib/aws/ec2.rb, line 346
def reserved_instances
  ReservedInstancesCollection.new(:config => config)
end
reserved_instances_offerings() click to toggle source

@return [ReservedInstancesOfferingCollection] A collection representing all

reserved instance offerings that may be purchased.
# File lib/aws/ec2.rb, line 352
def reserved_instances_offerings
  ReservedInstancesOfferingCollection.new(:config => config)
end
route_tables() click to toggle source

@return [RouteTableCollection] Returns a collection that represents

all of the route tables for this account.
# File lib/aws/ec2.rb, line 382
def route_tables
  RouteTableCollection.new(:config => config)
end
security_groups() click to toggle source

@return [SecurityGroupCollection] A collection representing all security

groups.
# File lib/aws/ec2.rb, line 299
def security_groups
  SecurityGroupCollection.new(:config => config)
end
snapshots() click to toggle source

@return [SnapshotCollection] A collection representing

all EBS snapshots available to your account.
# File lib/aws/ec2.rb, line 358
def snapshots
  SnapshotCollection.new(:config => config)
end
subnets() click to toggle source

@return [SubnetCollection] Returns a collection that represents all

of the subnets associated with this account (across all VPCs).
# File lib/aws/ec2.rb, line 370
def subnets
  SubnetCollection.new(:config => config)
end
tags() click to toggle source

@return [TagCollection] A collection representing all EC2 tags for

all resource types.
# File lib/aws/ec2.rb, line 316
def tags
  TagCollection.new(:config => config)
end
volumes() click to toggle source

@return [VolumeCollection] A collection representing

all EBS volumes available to your account.
# File lib/aws/ec2.rb, line 340
def volumes
  VolumeCollection.new(:config => config)
end
vpcs() click to toggle source

@return [VPCCollection] A collection representing

all VPCs in your account.
# File lib/aws/ec2.rb, line 364
def vpcs
  VPCCollection.new(:config => config)
end
vpn_connections() click to toggle source

@return [VPNConnections] Returns a collection that

represents all of vpn connections for this account.
# File lib/aws/ec2.rb, line 418
def vpn_connections
  VPNConnectionCollection.new(:config => config)
end
vpn_gateways() click to toggle source

@return [VPNGatewayCollection] Returns a collection that

represents all of the vpn gateways for this account.
# File lib/aws/ec2.rb, line 406
def vpn_gateways
  VPNGatewayCollection.new(:config => config)
end