AWS base images for Ruby Using an AWS base image Using a non-AWS base image

Deploy Ruby Lambda functions with container images

There are three ways to build a container image for a Ruby Lambda function:

Using an AWS base image for Ruby

The AWS base images are preloaded with a language runtime, a runtime interface client to manage the interaction between Lambda and your function code, and a runtime interface emulator for local testing.
Using an AWS OS-only base image

AWS OS-only base images contain an Amazon Linux distribution and the runtime interface emulator. These images are commonly used to create container images for compiled languages, such as Go and Rust, and for a language or language version that Lambda doesn't provide a base image for, such as Node.js 19. You can also use OS-only base images to implement a custom runtime. To make the image compatible with Lambda, you must include the runtime interface client for Ruby in the image.
Using a non-AWS base image

You can use an alternative base image from another container registry, such as Alpine Linux or Debian. You can also use a custom image created by your organization. To make the image compatible with Lambda, you must include the runtime interface client for Ruby in the image.

Tip

To reduce the time it takes for Lambda container functions to become active, see Use multi-stage builds in the Docker documentation. To build efficient container images, follow the Best practices for writing Dockerfiles.

This page explains how to build, test, and deploy container images for Lambda.

Topics

AWS base images for Ruby
Using an AWS base image for Ruby
Using an alternative base image with the runtime interface client

AWS base images for Ruby

AWS provides the following base images for Ruby:

Tags	Runtime	Operating system	Dockerfile	Deprecation
3.3	Ruby 3.3	Amazon Linux 2023	Dockerfile for Ruby 3.3 on GitHub
3.2	Ruby 3.2	Amazon Linux 2	Dockerfile for Ruby 3.2 on GitHub

Amazon ECR repository: gallery.ecr.aws/lambda/ruby

Using an AWS base image for Ruby

To complete the steps in this section, you must have the following:

To create a container image for Ruby

Create a directory for the project, and then switch to that directory.
```
mkdir example
cd example
```
Create a new file called Gemfile. This is where you list your application's required RubyGems packages. The AWS SDK for Ruby is available from RubyGems. You should choose specific AWS service gems to install. For example, to use the Ruby gem for Lambda, your Gemfile should look like this:
```
source 'https://rubygems.org'

gem 'aws-sdk-lambda'
```
Alternatively, the aws-sdk gem contains every available AWS service gem. This gem is very large. We recommend that you use it only if you depend on many AWS services.
Install the dependencies specified in the Gemfile using bundle install.
```
bundle install
```
Create a new file called lambda_function.rb. You can add the following sample function code to the file for testing, or use your own.
Example Ruby function
```
module LambdaFunction
  class Handler
    def self.process(event:,context:)
      "Hello from Lambda!"
    end
  end
end
```

Create a new Dockerfile. The following is an example Dockerfile that uses an AWS base image. This Dockerfiles uses the following configuration:

Set the FROM property to the URI of the base image.
Use the COPY command to copy the function code and runtime dependencies to {LAMBDA_TASK_ROOT}, a Lambda-defined environment variable.
Set the CMD argument to the Lambda function handler.

Example Dockerfile


FROM public.ecr.aws/lambda/ruby:3.2

# Copy Gemfile and Gemfile.lock
COPY Gemfile Gemfile.lock ${LAMBDA_TASK_ROOT}/

# Install Bundler and the specified gems
RUN gem install bundler:2.4.20 && \
    bundle config set --local path 'vendor/bundle' && \
    bundle install

# Copy function code
COPY lambda_function.rb ${LAMBDA_TASK_ROOT}/    

# Set the CMD to your handler (could also be done as a parameter override outside of the Dockerfile)
CMD [ "lambda_function.LambdaFunction::Handler.process" ]

Build the Docker image with the docker build command. The following example names the image docker-image and gives it the test tag.
```
docker build --platform linux/amd64 -t docker-image:test .
```
Note
The command specifies the --platform linux/amd64 option to ensure that your container is compatible with the Lambda execution environment regardless of the architecture of your build machine. If you intend to create a Lambda function using the ARM64 instruction set architecture, be sure to change the command to use the --platform linux/arm64 option instead.

Start the Docker image with the docker run command. In this example, docker-image is the image name and test is the tag.
```
docker run --platform linux/amd64 -p 9000:8080 docker-image:test
```
This command runs the image as a container and creates a local endpoint at localhost:9000/2015-03-31/functions/function/invocations.

Note
If you built the Docker image for the ARM64 instruction set architecture, be sure to use the --platform linux/arm64 option instead of --platform linux/amd64.
From a new terminal window, post an event to the local endpoint.
Linux/macOS
In Linux and macOS, run the following curl command:
```
curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'
```
This command invokes the function with an empty event and returns a response. If you're using your own function code rather than the sample function code, you might want to invoke the function with a JSON payload. Example:
```
curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{"payload":"hello world!"}'
```
PowerShell
In PowerShell, run the following Invoke-WebRequest command:
```
Invoke-WebRequest -Uri "http://localhost:9000/2015-03-31/functions/function/invocations" -Method Post -Body '{}' -ContentType "application/json"
```
This command invokes the function with an empty event and returns a response. If you're using your own function code rather than the sample function code, you might want to invoke the function with a JSON payload. Example:
```
Invoke-WebRequest -Uri "http://localhost:9000/2015-03-31/functions/function/invocations" -Method Post -Body '{"payload":"hello world!"}' -ContentType "application/json"
```
Get the container ID.
```
docker ps
```
Use the docker kill command to stop the container. In this command, replace 3766c4ab331c with the container ID from the previous step.
```
docker kill 3766c4ab331c
```

To upload the image to Amazon ECR and create the Lambda function

Run the get-login-password command to authenticate the Docker CLI to your Amazon ECR registry.
- Set the --region value to the AWS Region where you want to create the Amazon ECR repository.
- Replace 111122223333 with your AWS account ID.
```
aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin 111122223333.dkr.ecr.us-east-1.amazonaws.com
```

Create a repository in Amazon ECR using the create-repository command.


aws ecr create-repository --repository-name hello-world --region us-east-1 --image-scanning-configuration scanOnPush=true --image-tag-mutability MUTABLE

Note

The Amazon ECR repository must be in the same AWS Region as the Lambda function.

If successful, you see a response like this:


{
    "repository": {
        "repositoryArn": "arn:aws:ecr:us-east-1:111122223333:repository/hello-world",
        "registryId": "111122223333",
        "repositoryName": "hello-world",
        "repositoryUri": "111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world",
        "createdAt": "2023-03-09T10:39:01+00:00",
        "imageTagMutability": "MUTABLE",
        "imageScanningConfiguration": {
            "scanOnPush": true
        },
        "encryptionConfiguration": {
            "encryptionType": "AES256"
        }
    }
}

Copy the repositoryUri from the output in the previous step.
Run the docker tag command to tag your local image into your Amazon ECR repository as the latest version. In this command:
- Replace docker-image:test with the name and tag of your Docker image.
- Replace <ECRrepositoryUri> with the repositoryUri that you copied. Make sure to include :latest at the end of the URI.
```
docker tag docker-image:test <ECRrepositoryUri>:latest
```
Example:
```
docker tag docker-image:test 111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
```
Run the docker push command to deploy your local image to the Amazon ECR repository. Make sure to include :latest at the end of the repository URI.
```
docker push 111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
```
Create an execution role for the function, if you don't already have one. You need the Amazon Resource Name (ARN) of the role in the next step.
Create the Lambda function. For ImageUri, specify the repository URI from earlier. Make sure to include :latest at the end of the URI.
```
aws lambda create-function \
  --function-name hello-world \
  --package-type Image \
  --code ImageUri=111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest \
  --role arn:aws:iam::111122223333:role/lambda-ex
```
Note
You can create a function using an image in a different AWS account, as long as the image is in the same Region as the Lambda function. For more information, see Amazon ECR cross-account permissions.

Invoke the function.


aws lambda invoke --function-name hello-world response.json

You should see a response like this:


{
  "ExecutedVersion": "$LATEST", 
  "StatusCode": 200
}

To see the output of the function, check the response.json file.

To update the function code, you must build the image again, upload the new image to the Amazon ECR repository, and then use the update-function-code command to deploy the image to the Lambda function.

Using an alternative base image with the runtime interface client

If you use an OS-only base image or an alternative base image, you must include the runtime interface client in your image. The runtime interface client extends the Lambda runtime API, which manages the interaction between Lambda and your function code.

Install the Lambda runtime interface client for Ruby using the RubyGems.org package manager:


gem install aws_lambda_ric

You can also download the Ruby runtime interface client from GitHub. The runtime interface client supports Ruby versions 2.5.x to 2.7.x.

The following example demonstrates how to build a container image for Ruby using a non-AWS base image. The example Dockerfile uses an official Ruby base image. The Dockerfile includes the runtime interface client.

To complete the steps in this section, you must have the following:

To create a container image for Ruby using an alternative base image

Create a directory for the project, and then switch to that directory.
```
mkdir example
cd example
```
Create a new file called Gemfile. This is where you list your application's required RubyGems packages. The AWS SDK for Ruby is available from RubyGems. You should choose specific AWS service gems to install. For example, to use the Ruby gem for Lambda, your Gemfile should look like this:
```
source 'https://rubygems.org'

gem 'aws-sdk-lambda'
```
Alternatively, the aws-sdk gem contains every available AWS service gem. This gem is very large. We recommend that you use it only if you depend on many AWS services.
Install the dependencies specified in the Gemfile using bundle install.
```
bundle install
```
Create a new file called lambda_function.rb. You can add the following sample function code to the file for testing, or use your own.
Example Ruby function
```
module LambdaFunction
  class Handler
    def self.process(event:,context:)
      "Hello from Lambda!"
    end
  end
end
```
Create a new Dockerfile. The following Dockerfile uses a Ruby base image instead of an AWS base image. The Dockerfile includes the runtime interface client for Ruby, which makes the image compatible with Lambda. Alternatively, you can add the runtime interface client to your application's Gemfile.
- Set the FROM property to the Ruby base image.
- Create a directory for the function code and an environment variable that points to that directory. In this example, the directory is /var/task, which mirrors the Lambda execution environment. However, you can choose any directory for the function code because the Dockerfile doesn't use an AWS base image.
- Set the ENTRYPOINT to the module that you want the Docker container to run when it starts. In this case, the module is the runtime interface client.
- Set the CMD argument to the Lambda function handler.
Example Dockerfile
```
FROM ruby:2.7

# Install the runtime interface client for Ruby
RUN gem install aws_lambda_ric

# Add the runtime interface client to the PATH
ENV PATH="/usr/local/bundle/bin:${PATH}"

# Create a directory for the Lambda function
ENV LAMBDA_TASK_ROOT=/var/task
RUN mkdir -p ${LAMBDA_TASK_ROOT}
WORKDIR ${LAMBDA_TASK_ROOT}

# Copy Gemfile and Gemfile.lock
COPY Gemfile Gemfile.lock ${LAMBDA_TASK_ROOT}/

# Install Bundler and the specified gems
RUN gem install bundler:2.4.20 && \
    bundle config set --local path 'vendor/bundle' && \
    bundle install

# Copy function code
COPY lambda_function.rb ${LAMBDA_TASK_ROOT}/    

# Set runtime interface client as default command for the container runtime
ENTRYPOINT [ "aws_lambda_ric" ]

# Set the CMD to your handler (could also be done as a parameter override outside of the Dockerfile)
CMD [ "lambda_function.LambdaFunction::Handler.process" ]
```
Build the Docker image with the docker build command. The following example names the image docker-image and gives it the test tag.
```
docker build --platform linux/amd64 -t docker-image:test .
```
Note
The command specifies the --platform linux/amd64 option to ensure that your container is compatible with the Lambda execution environment regardless of the architecture of your build machine. If you intend to create a Lambda function using the ARM64 instruction set architecture, be sure to change the command to use the --platform linux/arm64 option instead.

Use the runtime interface emulator to locally test the image. You can build the emulator into your image or install it on your local machine.

To install and run the runtime interface emulator on your local machine

From your project directory, run the following command to download the runtime interface emulator (x86-64 architecture) from GitHub and install it on your local machine.

Start the Docker image with the docker run command. Note the following:
- docker-image is the image name and test is the tag.
- aws_lambda_ric lambda_function.LambdaFunction::Handler.process is the ENTRYPOINT followed by the CMD from your Dockerfile.
Linux/macOS
```
docker run --platform linux/amd64 -d -v ~/.aws-lambda-rie:/aws-lambda -p 9000:8080 \
    --entrypoint /aws-lambda/aws-lambda-rie \
    docker-image:test \
        aws_lambda_ric lambda_function.LambdaFunction::Handler.process
```
PowerShell
```
docker run --platform linux/amd64 -d -v "$HOME\.aws-lambda-rie:/aws-lambda" -p 9000:8080 `
--entrypoint /aws-lambda/aws-lambda-rie `
docker-image:test `
    aws_lambda_ric lambda_function.LambdaFunction::Handler.process
```
This command runs the image as a container and creates a local endpoint at localhost:9000/2015-03-31/functions/function/invocations.

Note
If you built the Docker image for the ARM64 instruction set architecture, be sure to use the --platform linux/arm64 option instead of --platform linux/amd64.
Post an event to the local endpoint.
Linux/macOS
In Linux and macOS, run the following curl command:
```
curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{}'
```
This command invokes the function with an empty event and returns a response. If you're using your own function code rather than the sample function code, you might want to invoke the function with a JSON payload. Example:
```
curl "http://localhost:9000/2015-03-31/functions/function/invocations" -d '{"payload":"hello world!"}'
```
PowerShell
In PowerShell, run the following Invoke-WebRequest command:
```
Invoke-WebRequest -Uri "http://localhost:9000/2015-03-31/functions/function/invocations" -Method Post -Body '{}' -ContentType "application/json"
```
This command invokes the function with an empty event and returns a response. If you're using your own function code rather than the sample function code, you might want to invoke the function with a JSON payload. Example:
```
Invoke-WebRequest -Uri "http://localhost:9000/2015-03-31/functions/function/invocations" -Method Post -Body '{"payload":"hello world!"}' -ContentType "application/json"
```
Get the container ID.
```
docker ps
```
Use the docker kill command to stop the container. In this command, replace 3766c4ab331c with the container ID from the previous step.
```
docker kill 3766c4ab331c
```

To upload the image to Amazon ECR and create the Lambda function

Run the get-login-password command to authenticate the Docker CLI to your Amazon ECR registry.
- Set the --region value to the AWS Region where you want to create the Amazon ECR repository.
- Replace 111122223333 with your AWS account ID.
```
aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin 111122223333.dkr.ecr.us-east-1.amazonaws.com
```

Create a repository in Amazon ECR using the create-repository command.


aws ecr create-repository --repository-name hello-world --region us-east-1 --image-scanning-configuration scanOnPush=true --image-tag-mutability MUTABLE

Note

The Amazon ECR repository must be in the same AWS Region as the Lambda function.

If successful, you see a response like this:


{
    "repository": {
        "repositoryArn": "arn:aws:ecr:us-east-1:111122223333:repository/hello-world",
        "registryId": "111122223333",
        "repositoryName": "hello-world",
        "repositoryUri": "111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world",
        "createdAt": "2023-03-09T10:39:01+00:00",
        "imageTagMutability": "MUTABLE",
        "imageScanningConfiguration": {
            "scanOnPush": true
        },
        "encryptionConfiguration": {
            "encryptionType": "AES256"
        }
    }
}

Copy the repositoryUri from the output in the previous step.
Run the docker tag command to tag your local image into your Amazon ECR repository as the latest version. In this command:
- Replace docker-image:test with the name and tag of your Docker image.
- Replace <ECRrepositoryUri> with the repositoryUri that you copied. Make sure to include :latest at the end of the URI.
```
docker tag docker-image:test <ECRrepositoryUri>:latest
```
Example:
```
docker tag docker-image:test 111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
```
Run the docker push command to deploy your local image to the Amazon ECR repository. Make sure to include :latest at the end of the repository URI.
```
docker push 111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest
```
Create an execution role for the function, if you don't already have one. You need the Amazon Resource Name (ARN) of the role in the next step.
Create the Lambda function. For ImageUri, specify the repository URI from earlier. Make sure to include :latest at the end of the URI.
```
aws lambda create-function \
  --function-name hello-world \
  --package-type Image \
  --code ImageUri=111122223333.dkr.ecr.us-east-1.amazonaws.com/hello-world:latest \
  --role arn:aws:iam::111122223333:role/lambda-ex
```
Note
You can create a function using an image in a different AWS account, as long as the image is in the same Region as the Lambda function. For more information, see Amazon ECR cross-account permissions.

Invoke the function.


aws lambda invoke --function-name hello-world response.json

You should see a response like this:


{
  "ExecutedVersion": "$LATEST", 
  "StatusCode": 200
}

To see the output of the function, check the response.json file.

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Context

Deploy Ruby Lambda functions with container images

Tip

Topics

AWS base images for Ruby

Using an AWS base image for Ruby

To create a container image for Ruby

Example Ruby function

Example Dockerfile

Note

Note

To upload the image to Amazon ECR and create the Lambda function

Note

Note

Using an alternative base image with the runtime interface client

To create a container image for Ruby using an alternative base image

Example Ruby function

Example Dockerfile

Note

To install and run the runtime interface emulator on your local machine

Note

To upload the image to Amazon ECR and create the Lambda function

Note

Note