Class: CloudfrontInvalidator

Inherits:
Object
  • Object
show all
Defined in:
lib/cloudfront-invalidator.rb

Defined Under Namespace

Classes: TooManyInvalidationsInProgress

Constant Summary collapse

API_VERSION = 
'2012-05-05'
BASE_URL = 
"https://cloudfront.amazonaws.com/#{API_VERSION}/distribution/"
DOC_URL = 
"http://cloudfront.amazonaws.com/doc/#{API_VERSION}/"
BACKOFF_LIMIT = 
8192
BACKOFF_DELAY = 
0.025

Instance Method Summary collapse

Constructor Details

#initialize(aws_key, aws_secret, cf_dist_id) ⇒ CloudfrontInvalidator

Returns a new instance of CloudfrontInvalidator.



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# File 'lib/cloudfront-invalidator.rb', line 13

def initialize(aws_key, aws_secret, cf_dist_id)
  @aws_key, @aws_secret, @cf_dist_id = aws_key, aws_secret, cf_dist_id
end

Instance Method Details

#get_invalidation_detail_xml(invalidation_id) ⇒ Object 



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# File 'lib/cloudfront-invalidator.rb', line 106

def get_invalidation_detail_xml(invalidation_id)
  uri = URI.parse "#{BASE_URL}#{@cf_dist_id}/invalidation/#{invalidation_id}"
  http = Net::HTTP.new(uri.host, uri.port)
  http.use_ssl = true
  http.verify_mode = OpenSSL::SSL::VERIFY_NONE
  resp = http.send_request 'GET', uri.path, '', headers
  return resp.body
end

#headers ⇒ Object 



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# File 'lib/cloudfront-invalidator.rb', line 130

def headers
  date = Time.now.strftime('%a, %d %b %Y %H:%M:%S %Z')
  digest = HMAC::SHA1.new(@aws_secret)
  digest << date
  signature = Base64.encode64(digest.digest)
  {'Date' =>  date, 'Authorization' => "AWS #{@aws_key}:#{signature}"}
end

#invalidate(*keys) ⇒ Object 



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# File 'lib/cloudfront-invalidator.rb', line 17

def invalidate(*keys)
  keys = keys.flatten.map do |k| 
    k.start_with?('/') ? k : '/' + k 
  end
  
  uri = URI.parse "#{BASE_URL}#{@cf_dist_id}/invalidation"
  http = Net::HTTP.new(uri.host, uri.port)
  http.use_ssl = true
  http.verify_mode = OpenSSL::SSL::VERIFY_NONE
  body = xml_body(keys)

  delay = 1
  begin
    resp = http.send_request 'POST', uri.path, body, headers
    doc = REXML::Document.new resp.body
 
    # Create and raise an exception for any error the API returns to us.
    if resp.code.to_i != 201
      error_code = doc.elements["ErrorResponse/Error/Code"].text
      self.class.const_set(error_code,Class.new(StandardError)) unless self.class.const_defined?(error_code.to_sym)
      raise self.class.const_get(error_code).new(doc.elements["ErrorResponse/Error/Message"].text)
    end
  
  # Handle the common case of too many in progress by waiting until the others finish.
  rescue TooManyInvalidationsInProgress => e
    sleep delay * BACKOFF_DELAY
    delay *= 2 unless delay >= BACKOFF_LIMIT 
    STDERR.puts e.inspect
    retry
  end

  # If we are passed a block, poll on the status of this invalidation with truncated exponential backoff.
  if block_given?
    invalidation_id = doc.elements["Invalidation/Id"].text
    poll_invalidation(invalidation_id) do |status,time|
      yield status, time
    end
  end
  return resp
end

#list(show_detail = false) ⇒ Object 



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# File 'lib/cloudfront-invalidator.rb', line 71

def list(show_detail = false)
  uri = URI.parse "#{BASE_URL}#{@cf_dist_id}/invalidation"
  http = Net::HTTP.new(uri.host, uri.port)
  http.use_ssl = true
  http.verify_mode = OpenSSL::SSL::VERIFY_NONE
  resp = http.send_request 'GET', uri.path, '', headers

  doc = REXML::Document.new resp.body
  puts "MaxItems " + doc.elements["InvalidationList/MaxItems"].text + "; " + (doc.elements["InvalidationList/MaxItems"].text == "true" ? "truncated" : "not truncated")

  doc.each_element("/InvalidationList/InvalidationSummary") do |summary|
    invalidation_id = summary.elements["Id"].text
    summary_text = "ID " + invalidation_id + ": " + summary.elements["Status"].text

    if show_detail
      detail_doc = REXML::Document.new get_invalidation_detail_xml(invalidation_id)
      puts summary_text +
           "; Created at: " +
           detail_doc.elements["Invalidation/CreateTime"].text +
           '; Caller reference: "' +
           detail_doc.elements["Invalidation/InvalidationBatch/CallerReference"].text +
           '"'
      puts '  Invalidated URL paths:'
      
      puts "    " + detail_doc.elements.to_a('Invalidation/InvalidationBatch/Path').map { |path| path.text }.join(" ")
    else
      puts summary_text
    end
  end
end

#list_detail ⇒ Object 



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# File 'lib/cloudfront-invalidator.rb', line 102

def list_detail
  list(true)
end

#poll_invalidation(invalidation_id) ⇒ Object 



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# File 'lib/cloudfront-invalidator.rb', line 58

def poll_invalidation(invalidation_id)
  start = Time.now
  delay = 1
  loop do
    doc = REXML::Document.new get_invalidation_detail_xml(invalidation_id)
    status = doc.elements["Invalidation/Status"].text
    yield status, Time.now - start
    break if status != "InProgress"
    sleep delay * BACKOFF_DELAY
    delay *= 2 unless delay >= BACKOFF_LIMIT
  end
end

#xml_body(keys) ⇒ Object 



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# File 'lib/cloudfront-invalidator.rb', line 115

def xml_body(keys)
  xml = <<XML
<?xml version="1.0" encoding="UTF-8"?>
<InvalidationBatch xmlns="#{DOC_URL}">
<Paths>
  <Quantity>#{keys.size}</Quantity>
  <Items>
    #{keys.map{|k| "<Path>#{k}</Path>" }.join("\n    ")}
  </Items>
</Paths>
<CallerReference>#{self.class.to_s} on #{Socket.gethostname} at #{Time.now.to_i}</CallerReference>"
</InvalidationBatch>
XML
end