Class: Kiel::Cloud::RightAWS

Inherits:
Object
  • Object
show all
Includes:
AWSBase
Defined in:
lib/kiel/cloud/right_aws.rb

Overview

Implements the connection to the Amazon Web Services (AWS) using the Right-AWS gem.

Constant Summary collapse

RECOGNIZED_OPTIONS = 
[ :region, :credentials, :instance, :start_options ]

Constants included from AWSBase

AWSBase::INSTANCE_STARTUP_TIMEOUT

Instance Method Summary collapse

Methods included from AWSBase

#exists?

Constructor Details

#initialize(options = {}) ⇒ RightAWS

The contructor takes the following configuration options:

:region

A string naming the region to be used. If no region is given, North America is used by default.

:credentials

A hash containing the fields ‘access_key_id’ and ‘secret_access_key’ with the credential information to your amazon account.

:instance

An instance of the AWS::EC2. If that instance is given, no credentials: should be given. Kiel::Cloud::AWS will instead use this instance.

:start_options

Possible options are :key_name and :security_groups to set the name of the used ssh key and a security group, where ssh is enabled.



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# File 'lib/kiel/cloud/right_aws.rb', line 23

def initialize options = {}
    require 'right_aws'

    options.each_key do | key |
        raise ArgumentError, "unrecognized option \'#{key}\'" unless RECOGNIZED_OPTIONS.include? key
    end
                        
    @ec2 = options[ :instance ]
    @start_options = options[ :start_options ] || {}
    
    if @ec2 
        puts "\'credentials\' ignored as an instance was given too" if options.key? :credentials
    else
        raise ArgumentError, 'no credentials given' unless options.key? :credentials
        credentials = options[ :credentials ]
        
        raise ArgumentError, 'no :access_key_id given within credentials' unless credentials.key? :access_key_id
        raise ArgumentError, 'no :secret_access_key given within credentials' unless credentials.key? :secret_access_key         

        params = options.key?( :region ) ? { region: options[ :region ] } : {} 
        @ec2 = RightAws::Ec2.new credentials[ :access_key_id ], credentials[ :secret_access_key ], params
    end
end

Instance Method Details

#all_images_by_tags(tags) ⇒ Object

Finds all images where the given tags apply



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# File 'lib/kiel/cloud/right_aws.rb', line 48

def all_images_by_tags tags
    images = @ec2.describe_images_by_owner 'self'

    images = images.select do | image |
        image_tags = image[ :tags ]
        image_tags.merge( tags ) == image_tags 
    end
    
    images
end

#delete_image(tags) ⇒ Object

deletes the given images by tags. For now this function is used just for cleanup during tests.



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# File 'lib/kiel/cloud/right_aws.rb', line 151

def delete_image tags
    all_images_by_tags( tags ).each do | image | 
        @ec2.deregister_image image[ :aws_id ]
    end     
end

#dns_name(instance) ⇒ Object

the public dns name of the given instance



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# File 'lib/kiel/cloud/right_aws.rb', line 146

def dns_name instance
    @ec2.describe_instances( [ instance[ :aws_instance_id ] ] )[ 0 ][ :dns_name ]
end

#start_instance(image_name) ⇒ Object

starts a server instance in the cloud, returning a handle to that instance. the image is either named by an image id :id => ‘image_id’ or by a set of tags that match for just one image :tags => { ‘image_type’ => ‘application’, ‘base’ => ‘34’ }



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# File 'lib/kiel/cloud/right_aws.rb', line 90

def start_instance image_name
    options = @start_options.merge( if image_name.key?( :id )
        { image_id: image_name[ :id ] }
    else
        tags  = image_name[ :tags ]
        image = image_by_tags tags
        raise RuntimeError, "no image with tags: \'#{tags}\' found to start an instance" unless image
        
        { image_id: image[ :aws_id ] }
    end )
    
    instance = @ec2.launch_instances( 
        options[ :image_id ], image_id: options[ :image_id ], key_name: options[ :key_name ], group_names: options[ :security_groups ] )
    instance = instance[ 0 ]
                    
    begin
        wait_for_ec2 instance
        puts "ec2 instance \'#{dns_name instance}\' started."
    rescue 
        stop_instance instance
        raise
    end 
    
    instance
end

#stop_instance(instance) ⇒ Object

stops the given instance.



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# File 'lib/kiel/cloud/right_aws.rb', line 141

def stop_instance instance
    @ec2.terminate_instances( [ instance[ :aws_instance_id ] ] )
end

#store_image(instance, tags) ⇒ Object

store the given instance and add the hash of tags to the image.



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# File 'lib/kiel/cloud/right_aws.rb', line 117

def store_image instance, tags
    begin
        puts "waiting 2 minutes before starting to take the image..."
        sleep 120
        puts "creating image..."

        image = @ec2.create_image( 
            instance[ :aws_instance_id ],
            :no_reboot => true,
            :description => "automaticaly created #{tags[ 'image_type' ]} image",
            :name => "#{tags[ 'image_type' ]} #{Digest::SHA1.hexdigest tags.inspect}" )
           
        puts "waiting for image to get ready..."
        wait_for_image image

        puts "image was created, adding tags..."
        @ec2.create_tags( image, tags )
        puts "tags added."
    ensure
        stop_instance instance
    end
end