Class: Maze::AwsPublicIp

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

Overview

Determines the public IP address and port when running on Buildkite with the Elastic CI Stack for AWS

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ AwsPublicIp

Returns a new instance of AwsPublicIp.



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# File 'lib/maze/aws_public_ip.rb', line 13

def initialize
  # This class is only relevant on Buildkite
  return unless ENV['BUILDKITE']

  @ip = determine_public_ip
  @port = determine_public_port Maze.config.port
end

Instance Attribute Details

#host ⇒ Object (readonly)

Returns the value of attribute host.



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# File 'lib/maze/aws_public_ip.rb', line 6

def host
  @host
end

#port ⇒ Object (readonly)

Returns the value of attribute port.



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# File 'lib/maze/aws_public_ip.rb', line 7

def port
  @port
end

Instance Method Details

#address ⇒ Object 



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# File 'lib/maze/aws_public_ip.rb', line 9

def address
  "#{@ip}:#{@port}"
end

#determine_public_ip ⇒ Object

Determines the public IP address of the running AWS instance



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# File 'lib/maze/aws_public_ip.rb', line 22

def determine_public_ip
  # 169.254.169.254 is the address of the AWS instance metadata service
  # See https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-retrieval.html
  token = `curl --silent -H "X-aws-ec2-metadata-token-ttl-seconds: 120" -XPUT http://169.254.169.254/latest/api/token`
  `curl -H "X-aws-ec2-metadata-token: #{token}" --silent -XGET http://169.254.169.254/latest/meta-data/public-ipv4`
end

#determine_public_port(local_port) ⇒ Object

Determines the external port of the running Docker container that’s associated with the port given

Parameters:

  • local_port —

    Local port to find the external port for



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# File 'lib/maze/aws_public_ip.rb', line 31

def determine_public_port(local_port)
  port = 0
  count = 0
  max_attempts = 30
  invalid_response_retries = 0
  max_invalid_retries = 2

  # Give up after 30 seconds
  while port == 0 && count < max_attempts do
    hostname = ENV['HOSTNAME']
    command = "curl --silent -XGET --unix-socket /var/run/docker.sock http://localhost/containers/#{hostname}/json"
    result = Maze::Runner.run_command(command)
    if result[1] == 0
      begin
        json_string = result[0][0].strip
        json_result = JSON.parse(json_string)
        port = json_result['NetworkSettings']['Ports']["#{local_port}/tcp"][0]['HostPort']
      rescue NoMethodError => error
        if invalid_response_retries >= max_invalid_retries
          Bugsnag.notify error
          $logger.error "Public port response was invalid or incomplete: #{json_string}"
          $logger.error "This has occurred more than maximum allowed #{max_invalid_retries}, exiting port process"
          return 0
        else
          invalid_response_retries += 1
          $logger.warn "Public port response was invalid or incomplete: #{json_string}"
          $logger.warn "Attempting to acquire public port again, retry attempt: #{invalid_response_retries}"
        end
      rescue StandardError => error
        Bugsnag.notify error
        $logger.error "Unable to parse public port from: #{json_string}"
        return 0
      end
    end

    count += 1
    sleep 1 if port == 0 && count < max_attempts
  end
  $logger.error "Failed to determine public port within #{max_attempts} attempts" if port == 0 && count == max_attempts

  port
end