Class: Jets::Preheat

Inherits:
Object
  • Object
show all
Extended by:
Memoist
Includes:
AwsServices
Defined in:
lib/jets/preheat.rb

Class Method Summary collapse

Instance Method Summary collapse

Methods included from AwsServices

#apigateway, #aws_lambda, #aws_options, #cfn, #dynamodb, #logs, #s3, #s3_resource, #sns, #sqs, #sts

Methods included from AwsServices::StackStatus

#lookup, #stack_exists?, #stack_in_progress?

Methods included from AwsServices::GlobalMemoist

included

Constructor Details

#initialize(options) ⇒ Preheat

Returns a new instance of Preheat.



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# File 'lib/jets/preheat.rb', line 19

def initialize(options)
  @options = options # passed to Call.new options
  @options[:mute_output] = true if @options[:mute_output].nil?
  @options[:lambda_proxy] = false # do not transform controller event from {"event": "1"} to {"queryStringParameters":{"_prewarm":"1"}}
end

Class Method Details

.warm(function_name, options = {}) ⇒ Object

Examples:

Jets::Preheat.warm("posts_controller-index")
Jets::Preheat.warm("jets-preheat_job-warm")



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# File 'lib/jets/preheat.rb', line 11

def self.warm(function_name, options={})
  Preheat.new(options).warm(function_name)
end

.warm_all(options = {}) ⇒ Object 



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# File 'lib/jets/preheat.rb', line 15

def self.warm_all(options={})
  Preheat.new(options).warm_all
end

Instance Method Details

#all_functions ⇒ Object

Returns:

[
  "demo-posts_controller-index",
  "demo-posts_controller-show",
  ...
]

or (for one lambda per controller)

[
  "demo-posts_controller",
  "demo-up_controller",
  ...
]



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# File 'lib/jets/preheat.rb', line 81

def all_functions
  parent_stack = cfn.describe_stack_resources(stack_name: Jets::Names.parent_stack_name)
  parent_resources = parent_stack.stack_resources.select do |resource|
    resource.logical_resource_id =~ /Controller$/ # only controller functions
  end
  physical_resource_ids = parent_resources.map(&:physical_resource_id)
  resources = physical_resource_ids.inject([]) do |acc, physical_resource_id|
    stack_resources = cfn.describe_stack_resources(stack_name: physical_resource_id).stack_resources
    stack_resources.each do |stack_resource|
      acc << stack_resource if stack_resource.logical_resource_id.ends_with?('LambdaFunction') # only functions
    end
    acc
  end
  resources.map(&:physical_resource_id) # function names
end

#classes ⇒ Object 



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# File 'lib/jets/preheat.rb', line 98

def classes
  Jets::Cfn::Builder.app_files.map do |path|
    next if path.include?("preheat_job.rb") # dont want to cause an infinite loop, just in case
    next unless path =~ %r{app/controllers} # only prewarm controllers

    class_path = path.sub(%r{.*app/\w+/},'').sub(/\.rb$/,'')
    class_name = class_path.camelize
    # IE: PostsController
    class_name.constantize # load app/**/* class definition
  end.compact
end

#warm(function_name) ⇒ Object

Makes remote call to the Lambda function.



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# File 'lib/jets/preheat.rb', line 26

def warm(function_name)
  Jets::Commands::Call::Caller.new(function_name, '{"_prewarm": "1"}', @options).run unless Jets.env.test?
end

#warm_all ⇒ Object

Loop through all methods for each class and makes special prewarm call to each method.



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# File 'lib/jets/preheat.rb', line 31

def warm_all
  threads = []
  all_functions.each do |function_name|
    next if function_name.include?('jets-public_controller') # handled by warm_public_controller_more
    threads << Thread.new do
      warm(function_name)
    end
  end
  threads.each { |t| t.join }

  # Warm the these controllers more since they can be hit more often
  warm_public_controller_more

  # return the funciton names so we can see in the Lambda console
  # the functions being prewarmed
  all_functions
end

#warm_public_controller_more ⇒ Object 



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# File 'lib/jets/preheat.rb', line 49

def warm_public_controller_more
  function_name = 'jets-public_controller-show' # key function name
  return unless all_functions.include?(function_name)

  public_ratio = Jets.config.prewarm.public_ratio
  return if public_ratio == 0

  puts "Prewarming the public controller extra at a ratio of #{public_ratio}" unless @options[:mute]

  threads = []
  public_ratio.times do
    threads << Thread.new do
      warm(function_name)
    end
  end
  threads.each { |t| t.join }
end