Module: Lono::AwsServices::Stack

Included in:
Helper
Defined in:
lib/lono/aws_services/stack.rb

Instance Method Summary collapse

Instance Method Details

#find_stack(stack_name) ⇒ Object 



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# File 'lib/lono/aws_services/stack.rb', line 29

def find_stack(stack_name)
  resp = cfn.describe_stacks(stack_name: stack_name)
  resp.stacks.first
rescue Aws::CloudFormation::Errors::ValidationError => e
  # example: Stack with id demo-web does not exist
  if e.message =~ /Stack with/ && e.message =~ /does not exist/
    nil
  else
    raise
  end
end

#stack_exists?(stack_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/lono/aws_services/stack.rb', line 3

def stack_exists?(stack_name)
  return true if testing_update?
  return false if @options[:noop]

  exist = nil
  begin
    # When the stack does not exist an exception is raised. Example:
    # Aws::CloudFormation::Errors::ValidationError: Stack with id blah does not exist
    cfn.describe_stacks(stack_name: stack_name)
    exist = true
  rescue Aws::CloudFormation::Errors::ValidationError => e
    if e.message =~ /does not exist/
      exist = false
    elsif e.message.include?("'stackName' failed to satisfy constraint")
      # Example of e.message when describe_stack with invalid stack name
      # "1 validation error detected: Value 'instance_and_route53' at 'stackName' failed to satisfy constraint: Member must satisfy regular expression pattern: [a-zA-Z][-a-zA-Z0-9]*|arn:[-a-zA-Z0-9:/._+]*"
      puts "Invalid stack name: #{stack_name}"
      puts "Full error message: #{e.message}"
      exit 1
    else
      raise # re-raise exception  because unsure what other errors can happen
    end
  end
  exist
end