Module: VScripts::AWS::Metadata

Included in:
EC2
Defined in:
lib/vscripts/aws/metadata.rb

Overview

This module contacts the AWS Metadata service to collect information about the EC2 instance.

Instance Method Summary collapse

Instance Method Details

#check_instance ⇒ Object

Fail if the current instance is not an EC2 instance



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# File 'lib/vscripts/aws/metadata.rb', line 43

def check_instance
  unless ec2_instance?
    abort 'FATAL: NOT an EC2 instance or could not connect to Metadata'
  end
end

#ec2_instance? ⇒ Boolean

Returns Check connection to service.

Returns:

  • (Boolean) —

    Check connection to service



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# File 'lib/vscripts/aws/metadata.rb', line 36

def ec2_instance?
  Net::HTTP.get_response(URI.parse(metadata_url)) && true
rescue
  false
end

#instance_id ⇒ String

Returns Get instance’s ID from metadata.

Returns:

  • (String) —

    Get instance’s ID from metadata



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# File 'lib/vscripts/aws/metadata.rb', line 26

def instance_id
  open("#{metadata_url}/instance-id").read
end

#metadata_url ⇒ String

Returns Metadata URL.

Returns:

  • (String) —

    Metadata URL



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# File 'lib/vscripts/aws/metadata.rb', line 10

def metadata_url
  'http://instance-data/latest/meta-data'
end

#public_hostname ⇒ String

Returns Get instance’s public hostname from metadata.

Returns:

  • (String) —

    Get instance’s public hostname from metadata



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# File 'lib/vscripts/aws/metadata.rb', line 31

def public_hostname
  open("#{metadata_url}/public-hostname").read
end

#region ⇒ String

Returns Get the region from the zone.

Returns:

  • (String) —

    Get the region from the zone



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# File 'lib/vscripts/aws/metadata.rb', line 21

def region
  zone[/^(.*[\d])[a-z]$/, 1]
end

#zone ⇒ String

Returns Get availability zone from metadata.

Returns:

  • (String) —

    Get availability zone from metadata



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# File 'lib/vscripts/aws/metadata.rb', line 15

def zone
  open("#{metadata_url}/placement/availability-zone")
    .read
end