Class: InstantEC2

Inherits:
Object
  • Object
show all
Defined in:
lib/instant_ec2.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(credentials: [], region: 'us-east-1') ⇒ InstantEC2

Returns a new instance of InstantEC2.



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# File 'lib/instant_ec2.rb', line 35

def initialize(credentials: [], region: 'us-east-1')

  @ec2 = Aws::EC2::Client.new(region: region, 
                             credentials: Aws::Credentials.new(*credentials))

  r = @ec2.describe_instances.reservations
  
  ids = @ec2.describe_instances[:reservations].inject({}) do |r, item| 
    x = item.instances[0]
    r.merge(x.image_id => x.instance_id)
  end

  rows = @ec2.describe_images(image_ids: ids.keys)[:images].\
                                               map{|x| [x.name, x.image_id] }

  @images = rows.inject([]) do |r, x|

    name, image_id = x
    
    r << EC2Instance.new({image_name: name, \
                                       instance_id: ids[image_id]}, self)
    
  end

  @hooks = {
    running: ->(ip){ 
      puts "%s: the instance is now accessible from %s" % [Time.now, ip]
    },
    stopping: ->(){ puts "%s: the instance is now stopping" % Time.now}
  }

end

Instance Attribute Details

#images ⇒ Object (readonly)

Returns the value of attribute images.



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# File 'lib/instant_ec2.rb', line 33

def images
  @images
end

Instance Method Details

#find_image(s) ⇒ Object 



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# File 'lib/instant_ec2.rb', line 68

def find_image(s)
  @images.find {|x| x[:image_name][/#{s}/i]}
end

#find_running ⇒ Object 



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# File 'lib/instant_ec2.rb', line 72

def find_running()

  r = @ec2.describe_instances.reservations.detect do |x|
    x.instances[0].state.name != 'stopped'
  end

end

#ip ⇒ Object 



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# File 'lib/instant_ec2.rb', line 80

def ip()
  r = self.find_running
  r.instances[0].public_ip_address if r
end

#on_running(&blk) ⇒ Object 



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# File 'lib/instant_ec2.rb', line 85

def on_running(&blk)
  @hooks[:running] = blk
end

#on_stopped(&blk) ⇒ Object 



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# File 'lib/instant_ec2.rb', line 130

def on_stopped(&blk)
  @hooks[:stopped] = blk
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/instant_ec2.rb', line 89

def running?
  self.ip ? true : false
end

#start(s, duration: nil) ⇒ Object

Launch an EC2 instance. Duration (optional) specified in minutes



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# File 'lib/instant_ec2.rb', line 95

def start(s, duration: nil)
  
  self.find_image(s).start duration: duration
  
end

#start_instance(id) ⇒ Object 



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# File 'lib/instant_ec2.rb', line 101

def start_instance(id)
  @ec2.start_instances instance_ids: [id]
  Thread.new { trigger_on_start() }
end

#stop ⇒ Object 



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# File 'lib/instant_ec2.rb', line 106

def stop()

  r = self.find_running()

  if r then
    
    puts 'stopping ...'
    
    self.stop_instance r.instances[0].instance_id      
    
  else
    puts 'no instances to stop'
  end
end

#stop_instance(id) ⇒ Object 



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# File 'lib/instant_ec2.rb', line 121

def stop_instance(id)
  @ec2.stop_instances instance_ids: [id]
  trigger_on_stopping()    
end

#stopped? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/instant_ec2.rb', line 126

def stopped?()
  self.ip.nil?
end