Class: LambdaSetup

Inherits:
Object
  • Object
show all
Defined in:
lib/hibernate/lambda_setup.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ LambdaSetup 



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# File 'lib/hibernate/lambda_setup.rb', line 9

def initialize
  config_loader = Hibernate::ConfigLoader.new
  @aws_region = config_loader.aws_credentials[:region]

  @lambda_role_name = "ec2-auto-shutdown-start"
  @lambda_handler = "ec2_auto_shutdown_start_function"
  @lambda_zip = "lambda_function.zip"
  @iam_client = Aws::IAM::Client.new(
    region: @aws_region,
    access_key_id: config_loader.aws_credentials[:access_key_id],
    secret_access_key: config_loader.aws_credentials[:secret_access_key]
  )

  @lambda_client = Aws::Lambda::Client.new(
    region: @aws_region,
    access_key_id: config_loader.aws_credentials[:access_key_id],
    secret_access_key: config_loader.aws_credentials[:secret_access_key]
  )
end

Instance Method Details

#create_lambda_function ⇒ Object 



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# File 'lib/hibernate/lambda_setup.rb', line 118

def create_lambda_function
  role_arn = @iam_client.get_role(role_name: @lambda_role_name).role.arn

  if lambda_function_exists?(@lambda_handler)
    puts "Lambda function '#{@lambda_handler}' already exists. Skipping creation."
  else
    zip_content = File.read(@lambda_zip)

    begin
      puts "Creating Lambda function..."
      @lambda_client.create_function({
        function_name: @lambda_handler,
        runtime: 'ruby3.2',
        role: role_arn,
        handler: "#{@lambda_handler}.lambda_handler",
        code: {
          zip_file: zip_content,
        },
        description: 'Lambda function to start and stop EC2 instances',
        timeout: 30
      })
      puts "Lambda function created."
    rescue Aws::Lambda::Errors::ServiceError => e
      puts "Error creating Lambda function: #{e.message}"
    end
  end
end

#create_lambda_role ⇒ Object 



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# File 'lib/hibernate/lambda_setup.rb', line 55

def create_lambda_role
  unless iam_role_exists?(@lambda_role_name)
    trust_policy = {
      Version: "2012-10-17",
      Statement: [
        {
          Effect: "Allow",
          Principal: {
            Service: "lambda.amazonaws.com"
          },
          Action: "sts:AssumeRole"
        }
      ]
    }.to_json

    puts "Creating IAM role..."
    @iam_client.create_role({
      role_name: @lambda_role_name,
      assume_role_policy_document: trust_policy
    })

    policy_document = {
      Version: "2012-10-17",
      Statement: [
        {
          Effect: "Allow",
          Action: [
            "ec2:DescribeInstances",
            "ec2:StartInstances",
            "ec2:StopInstances"
          ],
          Resource: "*"
        }
      ]
    }.to_json

    puts "Attaching custom EC2 policy to IAM role..."
    @iam_client.put_role_policy({
      role_name: @lambda_role_name,
      policy_name: "EC2ControlPolicy",
      policy_document: policy_document
    })

    @iam_client.attach_role_policy({
      role_name: @lambda_role_name,
      policy_arn: 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole'
    })

    puts "IAM role created and policies attached."
  else
    puts "IAM role '#{@lambda_role_name}' already exists. Skipping role creation."
  end
end

#create_zip_file(dir) ⇒ Object 



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# File 'lib/hibernate/lambda_setup.rb', line 29

def create_zip_file(dir)
  FileUtils.rm_f(@lambda_zip)

  Zip::File.open(@lambda_zip, Zip::File::CREATE) do |zip|
    Dir.glob(File.join('lib', 'hibernate',dir, '**', '*')).each do |file|
      next if File.directory?(file)
      zip_path = File.basename(file)
      puts "Adding #{file} as #{zip_path}"
      File.open(file, 'rb') do |io|
        zip.add(zip_path, io)
      end
    end
  end

  puts "ZIP file created: #{@lambda_zip}"
end

#iam_role_exists?(role_name) ⇒ Boolean 



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# File 'lib/hibernate/lambda_setup.rb', line 46

def iam_role_exists?(role_name)
  begin
    @iam_client.get_role(role_name: role_name)
    true
  rescue Aws::IAM::Errors::NoSuchEntity
    false
  end
end

#lambda_function_exists?(function_name) ⇒ Boolean 



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# File 'lib/hibernate/lambda_setup.rb', line 109

def lambda_function_exists?(function_name)
  begin
    @lambda_client.get_function(function_name: function_name)
    true
  rescue Aws::Lambda::Errors::ResourceNotFoundException
    false
  end
end

#run ⇒ Object 



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# File 'lib/hibernate/lambda_setup.rb', line 146

def run
  create_zip_file('lambda_function')
  create_lambda_role
  create_lambda_function
end