Class: Automan::Cloudformation::Replacer

Inherits:
Base
  • Object
show all
Defined in:
lib/automan/cloudformation/replacer.rb

Constant Summary

Constants included from Mixins::AwsCaller

Mixins::AwsCaller::S3_PROTO

Instance Attribute Summary

Attributes inherited from Base

#logger, #wait

Attributes included from Mixins::AwsCaller

#as, #cfn, #eb, #ec, #ec2, #elb, #r53, #rds, #s3

Instance Method Summary collapse

Methods inherited from Base

add_option, #log_options, #wait_until

Methods included from Mixins::AwsCaller

#account, #configure_aws, #looks_like_s3_path?, #parse_s3_path, #s3_object_exists?, #s3_read

Constructor Details

#initialize(options = {}) ⇒ Replacer

Returns a new instance of Replacer.



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# File 'lib/automan/cloudformation/replacer.rb', line 8

def initialize(options={})
  super
  @wait = Wait.new({
    delay: 60,
    attempts: 20, # 20 x 60s == 20m
    debug: true,
    rescuer:  WaitRescuer.new,
    logger:   @logger
  })
end

Instance Method Details

#ok_to_replace_instances?(stack_status, last_mod_time) ⇒ Boolean

so we want: when CREATE_COMPLETE | UPDATE_COMPLETE then continue when CREATE_FAILED | .ROLLBACK_. | ^DELETE_.* then raise error else try again

Returns:

  • (Boolean) 


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# File 'lib/automan/cloudformation/replacer.rb', line 32

def ok_to_replace_instances?(stack_status, last_mod_time)
  case stack_status
  when 'UPDATE_COMPLETE'
    if (Time.now - last_mod_time) <= (5*60)
      true
    else
      false
    end
  when 'CREATE_FAILED', /^.*ROLLBACK.*$/, /^DELETE.*/
    raise StackBrokenError, "Stack is in broken state #{stack_status}"
  else
    false
  end
end

#replace_instances ⇒ Object

terminate all running instances in the ASG so that new machines with the latest build will be started



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# File 'lib/automan/cloudformation/replacer.rb', line 67

def replace_instances
  log_options

  unless stack_exists?(name)
    raise StackDoesNotExistError, "Stack #{name} does not exist."
  end

  stack = cfn.stacks[name]
  unless stack_was_just_updated?(stack)
    logger.info "stack was not updated recently, not replacing instances."
    return
  end

  ex = WaitTimedOutError.new "Timed out waiting to replace instances."
  wait_until(ex) do
    ok_to_replace_instances?(stack.status, stack.last_updated_time)
  end

  logger.info "replacing all auto-scaling instances in #{name}"

  if stack_asg.nil?
    raise MissingAutoScalingGroupError, "No ASG found for stack #{name}"
  end

  stack_asg.ec2_instances.each do |i|
    if i.status == :running
      logger.info "terminating instance #{i.id}"
      i.terminate
    else
      logger.info "Not terminating #{i.id} due to status: #{i.status}"
    end
  end
end

#stack_asg ⇒ Object 



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# File 'lib/automan/cloudformation/replacer.rb', line 51

def stack_asg
  resources = cfn.stacks[name].resources
  asgs = resources.select {|i| i.resource_type == "AWS::AutoScaling::AutoScalingGroup"}
  if asgs.nil? || asgs.empty?
    return nil
  end
  asg_id = asgs.first.physical_resource_id
  as.groups[asg_id]
end

#stack_exists?(stack_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/automan/cloudformation/replacer.rb', line 47

def stack_exists?(stack_name)
  cfn.stacks[stack_name].exists?
end

#stack_was_just_updated?(stack) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/automan/cloudformation/replacer.rb', line 61

def stack_was_just_updated?(stack)
  stack.status == 'UPDATE_COMPLETE' && (Time.now - stack.last_updated_time) <= (5*60)
end