# Lambda examples using SDK for Ruby
The following code examples show you how to perform actions and implement common scenarios by using the AWS SDK for Ruby with Lambda.
*Basics* are code examples that show you how to perform the essential operations within a service.
*Actions* are code excerpts from larger programs and must be run in context. While actions show you how to call individual service functions, you can see actions in context in their related scenarios.
*Scenarios* are code examples that show you how to accomplish specific tasks by calling multiple functions within a service or combined with other AWS services.
Each example includes a link to the complete source code, where you can find instructions on how to set up and run the code in context.
**Topics**
+ [Get started](#get_started)
+ [Basics](#basics)
+ [Actions](#actions)
+ [Scenarios](#scenarios)
+ [Serverless examples](#serverless_examples)
## Get started
### Hello Lambda
The following code example shows how to get started using Lambda.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
require 'aws-sdk-lambda'
# Creates an AWS Lambda client using the default credentials and configuration
def lambda_client
Aws::Lambda::Client.new
end
# Lists the Lambda functions in your AWS account, paginating the results if necessary
def list_lambda_functions
lambda = lambda_client
# Use a pagination iterator to list all functions
functions = []
lambda.list_functions.each_page do |page|
functions.concat(page.functions)
end
# Print the name and ARN of each function
functions.each do |function|
puts "Function name: #{function.function_name}"
puts "Function ARN: #{function.function_arn}"
puts
end
puts "Total functions: #{functions.count}"
end
list_lambda_functions if __FILE__ == $PROGRAM_NAME
```
+ For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/ListFunctions) in *AWS SDK for Ruby API Reference*.
## Basics
### Learn the basics
The following code example shows how to:
+ Create an IAM role and Lambda function, then upload handler code.
+ Invoke the function with a single parameter and get results.
+ Update the function code and configure with an environment variable.
+ Invoke the function with new parameters and get results. Display the returned execution log.
+ List the functions for your account, then clean up resources.
For more information, see [Create a Lambda function with the console](https://docs.aws.amazon.com/lambda/latest/dg/getting-started-create-function.html).
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
Set up pre-requisite IAM permissions for a Lambda function capable of writing logs.
```
# Get an AWS Identity and Access Management (IAM) role.
#
# @param iam_role_name: The name of the role to retrieve.
# @param action: Whether to create or destroy the IAM apparatus.
# @return: The IAM role.
def manage_iam(iam_role_name, action)
case action
when 'create'
create_iam_role(iam_role_name)
when 'destroy'
destroy_iam_role(iam_role_name)
else
raise "Incorrect action provided. Must provide 'create' or 'destroy'"
end
end
private
def create_iam_role(iam_role_name)
role_policy = {
'Version': '2012-10-17',
'Statement': [
{
'Effect': 'Allow',
'Principal': { 'Service': 'lambda.amazonaws.com' },
'Action': 'sts:AssumeRole'
}
]
}
role = @iam_client.create_role(
role_name: iam_role_name,
assume_role_policy_document: role_policy.to_json
)
@iam_client.attach_role_policy(
{
policy_arn: 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole',
role_name: iam_role_name
}
)
wait_for_role_to_exist(iam_role_name)
@logger.debug("Successfully created IAM role: #{role['role']['arn']}")
sleep(10)
[role, role_policy.to_json]
end
def destroy_iam_role(iam_role_name)
@iam_client.detach_role_policy(
{
policy_arn: 'arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole',
role_name: iam_role_name
}
)
@iam_client.delete_role(role_name: iam_role_name)
@logger.debug("Detached policy & deleted IAM role: #{iam_role_name}")
end
def wait_for_role_to_exist(iam_role_name)
@iam_client.wait_until(:role_exists, { role_name: iam_role_name }) do |w|
w.max_attempts = 5
w.delay = 5
end
end
```
Define a Lambda handler that increments a number provided as an invocation parameter.
```
require 'logger'
# A function that increments a whole number by one (1) and logs the result.
# Requires a manually-provided runtime parameter, 'number', which must be Int
#
# @param event [Hash] Parameters sent when the function is invoked
# @param context [Hash] Methods and properties that provide information
# about the invocation, function, and execution environment.
# @return incremented_number [String] The incremented number.
def lambda_handler(event:, context:)
logger = Logger.new($stdout)
log_level = ENV['LOG_LEVEL']
logger.level = case log_level
when 'debug'
Logger::DEBUG
when 'info'
Logger::INFO
else
Logger::ERROR
end
logger.debug('This is a debug log message.')
logger.info('This is an info log message. Code executed successfully!')
number = event['number'].to_i
incremented_number = number + 1
logger.info("You provided #{number.round} and it was incremented to #{incremented_number.round}")
incremented_number.round.to_s
end
```
Zip your Lambda function into a deployment package.
```
# Creates a Lambda deployment package in .zip format.
#
# @param source_file: The name of the object, without suffix, for the Lambda file and zip.
# @return: The deployment package.
def create_deployment_package(source_file)
Dir.chdir(File.dirname(__FILE__))
if File.exist?('lambda_function.zip')
File.delete('lambda_function.zip')
@logger.debug('Deleting old zip: lambda_function.zip')
end
Zip::File.open('lambda_function.zip', create: true) do |zipfile|
zipfile.add('lambda_function.rb', "#{source_file}.rb")
end
@logger.debug("Zipping #{source_file}.rb into: lambda_function.zip.")
File.read('lambda_function.zip').to_s
rescue StandardError => e
@logger.error("There was an error creating deployment package:\n #{e.message}")
end
```
Create a new Lambda function.
```
# Deploys a Lambda function.
#
# @param function_name: The name of the Lambda function.
# @param handler_name: The fully qualified name of the handler function.
# @param role_arn: The IAM role to use for the function.
# @param deployment_package: The deployment package that contains the function code in .zip format.
# @return: The Amazon Resource Name (ARN) of the newly created function.
def create_function(function_name, handler_name, role_arn, deployment_package)
response = @lambda_client.create_function({
role: role_arn.to_s,
function_name: function_name,
handler: handler_name,
runtime: 'ruby2.7',
code: {
zip_file: deployment_package
},
environment: {
variables: {
'LOG_LEVEL' => 'info'
}
}
})
@lambda_client.wait_until(:function_active_v2, { function_name: function_name }) do |w|
w.max_attempts = 5
w.delay = 5
end
response
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error creating #{function_name}:\n #{e.message}")
rescue Aws::Waiters::Errors::WaiterFailed => e
@logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
end
```
Invoke your Lambda function with optional runtime parameters.
```
# Invokes a Lambda function.
# @param function_name [String] The name of the function to invoke.
# @param payload [nil] Payload containing runtime parameters.
# @return [Object] The response from the function invocation.
def invoke_function(function_name, payload = nil)
params = { function_name: function_name }
params[:payload] = payload unless payload.nil?
@lambda_client.invoke(params)
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error executing #{function_name}:\n #{e.message}")
end
```
Update your Lambda function's configuration to inject a new environment variable.
```
# Updates the environment variables for a Lambda function.
# @param function_name: The name of the function to update.
# @param log_level: The log level of the function.
# @return: Data about the update, including the status.
def update_function_configuration(function_name, log_level)
@lambda_client.update_function_configuration({
function_name: function_name,
environment: {
variables: {
'LOG_LEVEL' => log_level
}
}
})
@lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
w.max_attempts = 5
w.delay = 5
end
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error updating configurations for #{function_name}:\n #{e.message}")
rescue Aws::Waiters::Errors::WaiterFailed => e
@logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
end
```
Update your Lambda function's code with a different deployment package containing different code.
```
# Updates the code for a Lambda function by submitting a .zip archive that contains
# the code for the function.
#
# @param function_name: The name of the function to update.
# @param deployment_package: The function code to update, packaged as bytes in
# .zip format.
# @return: Data about the update, including the status.
def update_function_code(function_name, deployment_package)
@lambda_client.update_function_code(
function_name: function_name,
zip_file: deployment_package
)
@lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
w.max_attempts = 5
w.delay = 5
end
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error updating function code for: #{function_name}:\n #{e.message}")
nil
rescue Aws::Waiters::Errors::WaiterFailed => e
@logger.error("Failed waiting for #{function_name} to update:\n #{e.message}")
end
```
List all existing Lambda functions using the built-in paginator.
```
# Lists the Lambda functions for the current account.
def list_functions
functions = []
@lambda_client.list_functions.each do |response|
response['functions'].each do |function|
functions.append(function['function_name'])
end
end
functions
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error listing functions:\n #{e.message}")
end
```
Delete a specific Lambda function.
```
# Deletes a Lambda function.
# @param function_name: The name of the function to delete.
def delete_function(function_name)
print "Deleting function: #{function_name}..."
@lambda_client.delete_function(
function_name: function_name
)
print 'Done!'.green
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error deleting #{function_name}:\n #{e.message}")
end
```
+ For API details, see the following topics in *AWS SDK for Ruby API Reference*.
+ [CreateFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/CreateFunction)
+ [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/DeleteFunction)
+ [GetFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/GetFunction)
+ [Invoke](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/Invoke)
+ [ListFunctions](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/ListFunctions)
+ [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionCode)
+ [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionConfiguration)
## Actions
### `CreateFunction`
The following code example shows how to use `CreateFunction`.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
class LambdaWrapper
attr_accessor :lambda_client, :cloudwatch_client, :iam_client
def initialize
@lambda_client = Aws::Lambda::Client.new
@cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
@iam_client = Aws::IAM::Client.new(region: 'us-east-1')
@logger = Logger.new($stdout)
@logger.level = Logger::WARN
end
# Deploys a Lambda function.
#
# @param function_name: The name of the Lambda function.
# @param handler_name: The fully qualified name of the handler function.
# @param role_arn: The IAM role to use for the function.
# @param deployment_package: The deployment package that contains the function code in .zip format.
# @return: The Amazon Resource Name (ARN) of the newly created function.
def create_function(function_name, handler_name, role_arn, deployment_package)
response = @lambda_client.create_function({
role: role_arn.to_s,
function_name: function_name,
handler: handler_name,
runtime: 'ruby2.7',
code: {
zip_file: deployment_package
},
environment: {
variables: {
'LOG_LEVEL' => 'info'
}
}
})
@lambda_client.wait_until(:function_active_v2, { function_name: function_name }) do |w|
w.max_attempts = 5
w.delay = 5
end
response
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error creating #{function_name}:\n #{e.message}")
rescue Aws::Waiters::Errors::WaiterFailed => e
@logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
end
```
+ For API details, see [CreateFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/CreateFunction) in *AWS SDK for Ruby API Reference*.
### `DeleteFunction`
The following code example shows how to use `DeleteFunction`.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
class LambdaWrapper
attr_accessor :lambda_client, :cloudwatch_client, :iam_client
def initialize
@lambda_client = Aws::Lambda::Client.new
@cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
@iam_client = Aws::IAM::Client.new(region: 'us-east-1')
@logger = Logger.new($stdout)
@logger.level = Logger::WARN
end
# Deletes a Lambda function.
# @param function_name: The name of the function to delete.
def delete_function(function_name)
print "Deleting function: #{function_name}..."
@lambda_client.delete_function(
function_name: function_name
)
print 'Done!'.green
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error deleting #{function_name}:\n #{e.message}")
end
```
+ For API details, see [DeleteFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/DeleteFunction) in *AWS SDK for Ruby API Reference*.
### `GetFunction`
The following code example shows how to use `GetFunction`.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
class LambdaWrapper
attr_accessor :lambda_client, :cloudwatch_client, :iam_client
def initialize
@lambda_client = Aws::Lambda::Client.new
@cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
@iam_client = Aws::IAM::Client.new(region: 'us-east-1')
@logger = Logger.new($stdout)
@logger.level = Logger::WARN
end
# Gets data about a Lambda function.
#
# @param function_name: The name of the function.
# @return response: The function data, or nil if no such function exists.
def get_function(function_name)
@lambda_client.get_function(
{
function_name: function_name
}
)
rescue Aws::Lambda::Errors::ResourceNotFoundException => e
@logger.debug("Could not find function: #{function_name}:\n #{e.message}")
nil
end
```
+ For API details, see [GetFunction](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/GetFunction) in *AWS SDK for Ruby API Reference*.
### `Invoke`
The following code example shows how to use `Invoke`.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
class LambdaWrapper
attr_accessor :lambda_client, :cloudwatch_client, :iam_client
def initialize
@lambda_client = Aws::Lambda::Client.new
@cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
@iam_client = Aws::IAM::Client.new(region: 'us-east-1')
@logger = Logger.new($stdout)
@logger.level = Logger::WARN
end
# Invokes a Lambda function.
# @param function_name [String] The name of the function to invoke.
# @param payload [nil] Payload containing runtime parameters.
# @return [Object] The response from the function invocation.
def invoke_function(function_name, payload = nil)
params = { function_name: function_name }
params[:payload] = payload unless payload.nil?
@lambda_client.invoke(params)
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error executing #{function_name}:\n #{e.message}")
end
```
+ For API details, see [Invoke](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/Invoke) in *AWS SDK for Ruby API Reference*.
### `ListFunctions`
The following code example shows how to use `ListFunctions`.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
class LambdaWrapper
attr_accessor :lambda_client, :cloudwatch_client, :iam_client
def initialize
@lambda_client = Aws::Lambda::Client.new
@cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
@iam_client = Aws::IAM::Client.new(region: 'us-east-1')
@logger = Logger.new($stdout)
@logger.level = Logger::WARN
end
# Lists the Lambda functions for the current account.
def list_functions
functions = []
@lambda_client.list_functions.each do |response|
response['functions'].each do |function|
functions.append(function['function_name'])
end
end
functions
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error listing functions:\n #{e.message}")
end
```
+ For API details, see [ListFunctions](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/ListFunctions) in *AWS SDK for Ruby API Reference*.
### `UpdateFunctionCode`
The following code example shows how to use `UpdateFunctionCode`.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
class LambdaWrapper
attr_accessor :lambda_client, :cloudwatch_client, :iam_client
def initialize
@lambda_client = Aws::Lambda::Client.new
@cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
@iam_client = Aws::IAM::Client.new(region: 'us-east-1')
@logger = Logger.new($stdout)
@logger.level = Logger::WARN
end
# Updates the code for a Lambda function by submitting a .zip archive that contains
# the code for the function.
#
# @param function_name: The name of the function to update.
# @param deployment_package: The function code to update, packaged as bytes in
# .zip format.
# @return: Data about the update, including the status.
def update_function_code(function_name, deployment_package)
@lambda_client.update_function_code(
function_name: function_name,
zip_file: deployment_package
)
@lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
w.max_attempts = 5
w.delay = 5
end
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error updating function code for: #{function_name}:\n #{e.message}")
nil
rescue Aws::Waiters::Errors::WaiterFailed => e
@logger.error("Failed waiting for #{function_name} to update:\n #{e.message}")
end
```
+ For API details, see [UpdateFunctionCode](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionCode) in *AWS SDK for Ruby API Reference*.
### `UpdateFunctionConfiguration`
The following code example shows how to use `UpdateFunctionConfiguration`.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/lambda#code-examples).
```
class LambdaWrapper
attr_accessor :lambda_client, :cloudwatch_client, :iam_client
def initialize
@lambda_client = Aws::Lambda::Client.new
@cloudwatch_client = Aws::CloudWatchLogs::Client.new(region: 'us-east-1')
@iam_client = Aws::IAM::Client.new(region: 'us-east-1')
@logger = Logger.new($stdout)
@logger.level = Logger::WARN
end
# Updates the environment variables for a Lambda function.
# @param function_name: The name of the function to update.
# @param log_level: The log level of the function.
# @return: Data about the update, including the status.
def update_function_configuration(function_name, log_level)
@lambda_client.update_function_configuration({
function_name: function_name,
environment: {
variables: {
'LOG_LEVEL' => log_level
}
}
})
@lambda_client.wait_until(:function_updated_v2, { function_name: function_name }) do |w|
w.max_attempts = 5
w.delay = 5
end
rescue Aws::Lambda::Errors::ServiceException => e
@logger.error("There was an error updating configurations for #{function_name}:\n #{e.message}")
rescue Aws::Waiters::Errors::WaiterFailed => e
@logger.error("Failed waiting for #{function_name} to activate:\n #{e.message}")
end
```
+ For API details, see [UpdateFunctionConfiguration](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/UpdateFunctionConfiguration) in *AWS SDK for Ruby API Reference*.
## Scenarios
### Create an application to analyze customer feedback
The following code example shows how to create an application that analyzes customer comment cards, translates them from their original language, determines their sentiment, and generates an audio file from the translated text.
**SDK for Ruby**
This example application analyzes and stores customer feedback cards. Specifically, it fulfills the need of a fictitious hotel in New York City. The hotel receives feedback from guests in various languages in the form of physical comment cards. That feedback is uploaded into the app through a web client. After an image of a comment card is uploaded, the following steps occur:
+ Text is extracted from the image using Amazon Textract.
+ Amazon Comprehend determines the sentiment of the extracted text and its language.
+ The extracted text is translated to English using Amazon Translate.
+ Amazon Polly synthesizes an audio file from the extracted text.
The full app can be deployed with the AWS CDK. For source code and deployment instructions, see the project in [ GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/cross_service_examples/feedback_sentiment_analyzer).
**Services used in this example**
+ Amazon Comprehend
+ Lambda
+ Amazon Polly
+ Amazon Textract
+ Amazon Translate
## Serverless examples
### Connecting to an Amazon RDS database in a Lambda function
The following code example shows how to implement a Lambda function that connects to an RDS database. The function makes a simple database request and returns the result.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/lambda-function-connect-rds-iam) repository.
Connecting to an Amazon RDS database in a Lambda function using Ruby.
```
# Ruby code here.
require 'aws-sdk-rds'
require 'json'
require 'mysql2'
def lambda_handler(event:, context:)
endpoint = ENV['DBEndpoint'] # Add the endpoint without https"
port = ENV['Port'] # 3306
user = ENV['DBUser']
region = ENV['DBRegion'] # 'us-east-1'
db_name = ENV['DBName']
credentials = Aws::Credentials.new(
ENV['AWS_ACCESS_KEY_ID'],
ENV['AWS_SECRET_ACCESS_KEY'],
ENV['AWS_SESSION_TOKEN']
)
rds_client = Aws::RDS::AuthTokenGenerator.new(
region: region,
credentials: credentials
)
token = rds_client.auth_token(
endpoint: endpoint+ ':' + port,
user_name: user,
region: region
)
begin
conn = Mysql2::Client.new(
host: endpoint,
username: user,
password: token,
port: port,
database: db_name,
sslca: '/var/task/global-bundle.pem',
sslverify: true,
enable_cleartext_plugin: true
)
a = 3
b = 2
result = conn.query("SELECT #{a} + #{b} AS sum").first['sum']
puts result
conn.close
{
statusCode: 200,
body: result.to_json
}
rescue => e
puts "Database connection failed due to #{e}"
end
end
```
### Invoke a Lambda function from a Kinesis trigger
The following code example shows how to implement a Lambda function that receives an event triggered by receiving records from a Kinesis stream. The function retrieves the Kinesis payload, decodes from Base64, and logs the record contents.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda) repository.
Consuming an Kinesis event with Lambda using Ruby.
```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
require 'aws-sdk'
def lambda_handler(event:, context:)
event['Records'].each do |record|
begin
puts "Processed Kinesis Event - EventID: #{record['eventID']}"
record_data = get_record_data_async(record['kinesis'])
puts "Record Data: #{record_data}"
# TODO: Do interesting work based on the new data
rescue => err
$stderr.puts "An error occurred #{err}"
raise err
end
end
puts "Successfully processed #{event['Records'].length} records."
end
def get_record_data_async(payload)
data = Base64.decode64(payload['data']).force_encoding('UTF-8')
# Placeholder for actual async work
# You can use Ruby's asynchronous programming tools like async/await or fibers here.
return data
end
```
### Invoke a Lambda function from a DynamoDB trigger
The following code example shows how to implement a Lambda function that receives an event triggered by receiving records from a DynamoDB stream. The function retrieves the DynamoDB payload and logs the record contents.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda) repository.
Consuming a DynamoDB event with Lambda using Ruby.
```
def lambda_handler(event:, context:)
return 'received empty event' if event['Records'].empty?
event['Records'].each do |record|
log_dynamodb_record(record)
end
"Records processed: #{event['Records'].length}"
end
def log_dynamodb_record(record)
puts record['eventID']
puts record['eventName']
puts "DynamoDB Record: #{JSON.generate(record['dynamodb'])}"
end
```
### Invoke a Lambda function from a Amazon DocumentDB trigger
The following code example shows how to implement a Lambda function that receives an event triggered by receiving records from a DocumentDB change stream. The function retrieves the DocumentDB payload and logs the record contents.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-docdb-to-lambda) repository.
Consuming a Amazon DocumentDB event with Lambda using Ruby.
```
require 'json'
def lambda_handler(event:, context:)
event['events'].each do |record|
log_document_db_event(record)
end
'OK'
end
def log_document_db_event(record)
event_data = record['event'] || {}
operation_type = event_data['operationType'] || 'Unknown'
db = event_data.dig('ns', 'db') || 'Unknown'
collection = event_data.dig('ns', 'coll') || 'Unknown'
full_document = event_data['fullDocument'] || {}
puts "Operation type: #{operation_type}"
puts "db: #{db}"
puts "collection: #{collection}"
puts "Full document: #{JSON.pretty_generate(full_document)}"
end
```
### Invoke a Lambda function from an Amazon MSK trigger
The following code example shows how to implement a Lambda function that receives an event triggered by receiving records from an Amazon MSK cluster. The function retrieves the MSK payload and logs the record contents.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-msk-to-lambda) repository.
Consuming an Amazon MSK event with Lambda using Ruby.
```
require 'base64'
def lambda_handler(event:, context:)
# Iterate through keys
event['records'].each do |key, records|
puts "Key: #{key}"
# Iterate through records
records.each do |record|
puts "Record: #{record}"
# Decode base64
msg = Base64.decode64(record['value'])
puts "Message: #{msg}"
end
end
end
```
### Invoke a Lambda function from an Amazon S3 trigger
The following code example shows how to implement a Lambda function that receives an event triggered by uploading an object to an S3 bucket. The function retrieves the S3 bucket name and object key from the event parameter and calls the Amazon S3 API to retrieve and log the content type of the object.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-s3-to-lambda) repository.
Consuming an S3 event with Lambda using Ruby.
```
require 'json'
require 'uri'
require 'aws-sdk'
puts 'Loading function'
def lambda_handler(event:, context:)
s3 = Aws::S3::Client.new(region: 'region') # Your AWS region
# puts "Received event: #{JSON.dump(event)}"
# Get the object from the event and show its content type
bucket = event['Records'][0]['s3']['bucket']['name']
key = URI.decode_www_form_component(event['Records'][0]['s3']['object']['key'], Encoding::UTF_8)
begin
response = s3.get_object(bucket: bucket, key: key)
puts "CONTENT TYPE: #{response.content_type}"
return response.content_type
rescue StandardError => e
puts e.message
puts "Error getting object #{key} from bucket #{bucket}. Make sure they exist and your bucket is in the same region as this function."
raise e
end
end
```
### Invoke a Lambda function from an Amazon SNS trigger
The following code example shows how to implement a Lambda function that receives an event triggered by receiving messages from an SNS topic. The function retrieves the messages from the event parameter and logs the content of each message.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sns-to-lambda) repository.
Consuming an SNS event with Lambda using Ruby.
```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event:, context:)
event['Records'].map { |record| process_message(record) }
end
def process_message(record)
message = record['Sns']['Message']
puts("Processing message: #{message}")
rescue StandardError => e
puts("Error processing message: #{e}")
raise
end
```
### Invoke a Lambda function from an Amazon SQS trigger
The following code example shows how to implement a Lambda function that receives an event triggered by receiving messages from an SQS queue. The function retrieves the messages from the event parameter and logs the content of each message.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda) repository.
Consuming an SQS event with Lambda using Ruby.
```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
def lambda_handler(event:, context:)
event['Records'].each do |message|
process_message(message)
end
puts "done"
end
def process_message(message)
begin
puts "Processed message #{message['body']}"
# TODO: Do interesting work based on the new message
rescue StandardError => err
puts "An error occurred"
raise err
end
end
```
### Reporting batch item failures for Lambda functions with a Kinesis trigger
The following code example shows how to implement partial batch response for Lambda functions that receive events from a Kinesis stream. The function reports the batch item failures in the response, signaling to Lambda to retry those messages later.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-kinesis-to-lambda-with-batch-item-handling) repository.
Reporting Kinesis batch item failures with Lambda using Ruby.
```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
require 'aws-sdk'
def lambda_handler(event:, context:)
batch_item_failures = []
event['Records'].each do |record|
begin
puts "Processed Kinesis Event - EventID: #{record['eventID']}"
record_data = get_record_data_async(record['kinesis'])
puts "Record Data: #{record_data}"
# TODO: Do interesting work based on the new data
rescue StandardError => err
puts "An error occurred #{err}"
# Since we are working with streams, we can return the failed item immediately.
# Lambda will immediately begin to retry processing from this failed item onwards.
return { batchItemFailures: [{ itemIdentifier: record['kinesis']['sequenceNumber'] }] }
end
end
puts "Successfully processed #{event['Records'].length} records."
{ batchItemFailures: batch_item_failures }
end
def get_record_data_async(payload)
data = Base64.decode64(payload['data']).force_encoding('utf-8')
# Placeholder for actual async work
sleep(1)
data
end
```
### Reporting batch item failures for Lambda functions with a DynamoDB trigger
The following code example shows how to implement partial batch response for Lambda functions that receive events from a DynamoDB stream. The function reports the batch item failures in the response, signaling to Lambda to retry those messages later.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-ddb-to-lambda-with-batch-item-handling) repository.
Reporting DynamoDB batch item failures with Lambda using Ruby.
```
def lambda_handler(event:, context:)
records = event["Records"]
cur_record_sequence_number = ""
records.each do |record|
begin
# Process your record
cur_record_sequence_number = record["dynamodb"]["SequenceNumber"]
rescue StandardError => e
# Return failed record's sequence number
return {"batchItemFailures" => [{"itemIdentifier" => cur_record_sequence_number}]}
end
end
{"batchItemFailures" => []}
end
```
### Reporting batch item failures for Lambda functions with an Amazon SQS trigger
The following code example shows how to implement partial batch response for Lambda functions that receive events from an SQS queue. The function reports the batch item failures in the response, signaling to Lambda to retry those messages later.
**SDK for Ruby**
There's more on GitHub. Find the complete example and learn how to set up and run in the [Serverless examples](https://github.com/aws-samples/serverless-snippets/tree/main/integration-sqs-to-lambda-with-batch-item-handling) repository.
Reporting SQS batch item failures with Lambda using Ruby.
```
# Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
# SPDX-License-Identifier: Apache-2.0
require 'json'
def lambda_handler(event:, context:)
if event
batch_item_failures = []
sqs_batch_response = {}
event["Records"].each do |record|
begin
# process message
rescue StandardError => e
batch_item_failures << {"itemIdentifier" => record['messageId']}
end
end
sqs_batch_response["batchItemFailures"] = batch_item_failures
return sqs_batch_response
end
end
```