Spot Instances

README.md

@@ -24,6 +24,7 @@ EC2 and VPC.
 * Define region-specific configurations so Vagrant can manage machines
   in multiple regions.
 * Package running instances into new vagrant-aws friendly boxes
+* Spot Instance Support
 
 ## Usage
 
@@ -170,6 +171,11 @@ This provider exposes quite a few provider-specific configuration options:
   when you initiate shutdown from the instance.
 * `endpoint` - The endpoint URL for connecting to AWS (or an AWS-like service). Only required for non AWS clouds, such as [eucalyptus](https://github.com/eucalyptus/eucalyptus/wiki).
 
+* `spot_instance` - Boolean value; indicates whether the config is for a spot instance, or on-demand. For more information about spot instances, see the [AWS Documentation](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/how-spot-instances-work.html)
+* `spot_max_price` - Decimal value; state the maximum bid for your spot instance. If nil, it will compute average price in `region` for selected `instance_type`.
+* `spot_price_product_description` - The product description for the spot price history used to compute average price. Defaults to 'Linux/UNIX'. 
+* `spot_valid_until` - Timestamp; when this spot instance request should expire, destroying any related instances. Ignored if `spot_instance` is not true.
+
 These can be set like typical provider-specific configuration:
 
 ```ruby

lib/vagrant-aws/action/run_instance.rb

@@ -107,7 +107,11 @@ def call(env)
           end
 
           begin
-            server = env[:aws_compute].servers.create(options)
+            server = if region_config.spot_instance
+                       server_from_spot_request(env, region_config, options)
+                     else
+                       env[:aws_compute].servers.create(options)
+                     end
           rescue Fog::Compute::AWS::NotFound => e
             # Invalid subnet doesn't have its own error so we catch and
             # check the error message here.
@@ -212,6 +216,87 @@ def call(env)
           @app.call(env)
         end
 
+        # returns a fog server or nil
+        def server_from_spot_request(env, config, options)
+          if config.spot_max_price.nil?
+            spot_price_current = env[:aws_compute].describe_spot_price_history({
+              'StartTime' => Time.now.iso8601,
+              'EndTime' => Time.now.iso8601,
+              'InstanceType' => [config.instance_type],
+              'ProductDescription' => [config.spot_price_product_description.nil? ? 'Linux/UNIX' : config.spot_price_product_description]
+            })
+
+            spot_price_current.body['spotPriceHistorySet'].each do |set|
+              (@price_set ||= []) << set['spotPrice'].to_f
+            end
+
+            if @price_set.nil?
+              raise Errors::FogError,
+                :message => "Could not find any history spot prices."
+            end
+
+            avg_price = @price_set.inject(0.0) { |sum, el| sum + el } / @price_set.size
+
+            # make the bid 10% higher than the average
+            price = (avg_price * 1.1).round(4)
+          else
+            price = config.spot_max_price
+          end
+
+          options.merge!({
+            :price => price,
+            :valid_until => config.spot_valid_until
+          })
+
+          env[:ui].info(I18n.t("vagrant_aws.launching_spot_instance"))
+          env[:ui].info(" -- Price: #{price}")
+          env[:ui].info(" -- Valid until: #{config.spot_valid_until}") if config.spot_valid_until
+
+          # create the spot instance
+          spot_req = env[:aws_compute].spot_requests.create(options)
+
+          @logger.info("Spot request ID: #{spot_req.id}")
+
+          # initialize state
+          status_code = ""
+          while true
+            sleep 5
+
+            spot_req.reload()
+
+            # display something whenever the status code changes
+            if status_code != spot_req.state
+              env[:ui].info(spot_req.fault)
+              status_code = spot_req.state
+            end
+            spot_state = spot_req.state.to_sym
+            case spot_state
+            when :not_created, :open
+              @logger.debug("Spot request #{spot_state} #{status_code}, waiting")
+            when :active
+              break; # :)
+            when :closed, :cancelled, :failed
+              msg = "Spot request #{spot_state} #{status_code}, aborting"
+              @logger.error(msg)
+              raise Errors::FogError, :message => msg
+            else
+              @logger.debug("Unknown spot state #{spot_state} #{status_code}, waiting")
+            end
+          end
+          # cancel the spot request but let the server go thru
+          spot_req.destroy()
+
+          server = env[:aws_compute].servers.get(spot_req.instance_id)
+
+          # Spot Instances don't support tagging arguments on creation
+          # Retrospectively tag the server to handle this
+          if !config.tags.empty?
+            env[:aws_compute].create_tags(server.identity, config.tags)
+          end
+
+          server
+        end
+
         def recover(env)
           return if env["vagrant.error"].is_a?(Vagrant::Errors::VagrantError)
 

lib/vagrant-aws/config.rb

@@ -196,6 +196,26 @@ class Config < Vagrant.plugin("2", :config)
       # @return [String]
       attr_accessor :aws_profile
 
+      # Launch as spot instance
+      #
+      # @return [Boolean]
+      attr_accessor :spot_instance
+
+      # Spot request max price
+      #
+      # @return [String]
+      attr_accessor :spot_max_price
+
+      # Spot request validity
+      #
+      # @return [Time]
+      attr_accessor :spot_valid_until
+
+      # The product description for the spot price history
+      #
+      # @return [String]
+      attr_accessor :spot_price_product_description
+
       def initialize(region_specific=false)
         @access_key_id             = UNSET_VALUE
         @ami                       = UNSET_VALUE
@@ -233,6 +253,9 @@ def initialize(region_specific=false)
         @tenancy                   = UNSET_VALUE
         @aws_dir                   = UNSET_VALUE
         @aws_profile               = UNSET_VALUE
+        @spot_instance             = UNSET_VALUE
+        @spot_max_price            = UNSET_VALUE
+        @spot_valid_until          = UNSET_VALUE
 
         # Internal state (prefix with __ so they aren't automatically
         # merged)
@@ -409,6 +432,18 @@ def finalize!
         # default to nil
         @kernel_id = nil if @kernel_id == UNSET_VALUE
 
+        # By default don't use spot requests
+        @spot_instance = false if @spot_instance == UNSET_VALUE
+
+        # default to nil
+        @spot_max_price = nil if @spot_max_price == UNSET_VALUE
+
+        # Default: Request is effective indefinitely.
+        @spot_valid_until = nil if @spot_valid_until == UNSET_VALUE
+
+        # default to nil
+        @spot_price_product_description = nil if @spot_price_product_description == UNSET_VALUE
+
         # Compile our region specific configurations only within
         # NON-REGION-SPECIFIC configurations.
         if !@__region_specific
@@ -479,14 +514,14 @@ def get_region_config(name)
 
 
     class Credentials < Vagrant.plugin("2", :config)
-      # This module reads AWS config and credentials. 
+      # This module reads AWS config and credentials.
       # Behaviour aims to mimic what is described in AWS documentation:
       # http://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html
       # http://docs.aws.amazon.com/cli/latest/topic/config-vars.html
       # Which is the following (stopping at the first successful case):
       # 1) read config and credentials from environment variables
       # 2) read config and credentials from files at location defined by environment variables
-      # 3) read config and credentials from files at default location 
+      # 3) read config and credentials from files at default location
       #
       # The mandatory fields for a successful "get credentials" are the id and the secret keys.
       # Region is not required since Config#finalize falls back to sensible defaults.

locales/en.yml

@@ -18,6 +18,8 @@ en:
 
     launching_instance: |-
       Launching an instance with the following settings...
+    launching_spot_instance: |-
+       Launching a spot request instance with the following settings...
     launch_no_keypair: |-
       Warning! You didn't specify a keypair to launch your instance with.
       This can sometimes result in not being able to access your instance.
@@ -104,7 +106,7 @@ en:
         Error: %{err}
       instance_package_timeout: |-
         The AMI failed to become "ready" in AWS. The timeout currently
-        set waiting for the instance to become ready is %{timeout} seconds. For 
+        set waiting for the instance to become ready is %{timeout} seconds. For
         larger instances AMI burning may take long periods of time. Please
         ensure the timeout is set high enough, it can be changed by adjusting
         the `instance_package_timeout` configuration on the AWS provider.

spec/vagrant-aws/config_spec.rb

@@ -58,6 +58,10 @@
     its("associate_public_ip")     { should == false }
     its("unregister_elb_from_az") { should == true }
     its("tenancy")     { should == "default" }
+    its("spot_instance")     { should == false }
+    its("spot_max_price")    { should be_nil }
+    its("spot_price_product_description")  { should be_nil }
+    its("spot_valid_until")  { should be_nil }
   end
 
   describe "overriding defaults" do