Module: CfnStatus::AwsService

Included in:
CfnStatus
Defined in:
lib/cfn_status/aws_service.rb

Instance Method Summary collapse

Instance Method Details

#aws_options ⇒ Object

Override the AWS retry settings.

The aws-sdk-core has exponential backup with this formula:

2 ** c.retries * c.config.retry_base_delay

Source:

https://github.com/aws/aws-sdk-ruby/blob/version-3/gems/aws-sdk-core/lib/aws-sdk-core/plugins/retry_errors.rb

So the max delay will be 2 ** 7 * 0.6 = 76.8s

Only scoping this to deploy because dont want to affect people’s application that use the aws sdk.

There is also additional rate backoff logic elsewhere, since this is only scoped to deploys.

Useful links:

https://github.com/aws/aws-sdk-ruby/blob/master/gems/aws-sdk-core/lib/aws-sdk-core/plugins/retry_errors.rb
https://docs.aws.amazon.com/apigateway/latest/developerguide/limits.html



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# File 'lib/cfn_status/aws_service.rb', line 70

def aws_options
  options = {
    retry_limit: 7, # default: 3
    retry_base_delay: 0.6, # default: 0.3
  }
  options.merge!(
    log_level: :debug,
    logger: Logger.new($stdout),
  ) if ENV['CFN_STATUS_DEBUG_AWS_SDK']
  options
end

#cfn ⇒ Object 



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# File 'lib/cfn_status/aws_service.rb', line 5

def cfn
  @cfn ||= Aws::CloudFormation::Client.new(aws_options)
end

#find_stack(stack_name) ⇒ Object 



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# File 'lib/cfn_status/aws_service.rb', line 35

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

#rollback_complete?(stack) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cfn_status/aws_service.rb', line 47

def rollback_complete?(stack)
  stack&.stack_status == 'ROLLBACK_COMPLETE'
end

#stack_exists?(stack_name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cfn_status/aws_service.rb', line 9

def stack_exists?(stack_name)
  return true if ENV['TEST']
  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