zzstoatzz / prefect-lambda

deploy observable lambdas

Steps to deploy a Lambda function to AWS using a container image and the AWS CLI:

Step 1: Prerequisites

• Ensure you have an AWS account

Step 2: Create a Dockerfile

Dockerfile:

FROM public.ecr.aws/lambda/python:3.12

COPY requirements.txt ${LAMBDA_TASK_ROOT}

RUN pip install uv
RUN uv venv
RUN uv pip install -r requirements.txt

COPY .prefect/ ${LAMBDA_TASK_ROOT}/.prefect/
COPY handlers.py ${LAMBDA_TASK_ROOT}

ENV PREFECT_HOME=${LAMBDA_TASK_ROOT}

CMD [ "handlers.lambda_handler" ]

Note

What is uv you ask? Change your life today.

Step 3: Write your Lambda function code

• Create a new file named lambda_function.py (or any desired name) and write your Lambda function code.
• Example Lambda function code:

from prefect import flow

@flow(log_prints=True)
def lambda_handler(event, context):
    """AWS Lambda function entrypoint"""
    print(f"{event=}, {context=}")

    return {"message": "Hello, World!"}

Tip

To do the rest of the steps automatically, see this GitHub Action. Also, use gh secret set -f .env to set all environment variables in your .env file as GitHub Actions secrets.

Manual steps

Step 4: Build the Docker image

• Build the Docker image using the Dockerfile.

docker build \
  --platform linux/amd64 \
  --tag your-account-id.dkr.ecr.your-region.amazonaws.com/my-lambda-function:latest \
  .

Step 5: Create an Amazon ECR repository

• Create a new Amazon ECR repository to store your Docker image.

aws ecr create-repository --repository-name my-lambda-function

Step 6: Authenticate with Amazon ECR

• Authenticate your Docker client with Amazon ECR.

aws ecr get-login-password --region your-region | docker login --username AWS --password-stdin your-account-id.dkr.ecr.your-region.amazonaws.com

Step 7: Push the Docker image to Amazon ECR

• Push the tagged Docker image to your Amazon ECR repository.

docker push your-account-id.dkr.ecr.your-region.amazonaws.com/my-lambda-function:latest

Step 8: Create the Lambda function

• Create the Lambda function using the AWS CLI, specifying the function name, package type, code image URI, and IAM role.

aws lambda create-function --function-name my-lambda-function \
  --package-type Image \
  --code ImageUri=your-account-id.dkr.ecr.your-region.amazonaws.com/my-lambda-function:latest \
  --role arn:aws:iam::your-account-id:role/my-lambda-role

Step 9: Set environment variables for the Lambda function

• Set the environment variables for your Lambda function using the AWS CLI.

aws lambda update-function-configuration --function-name my-lambda-function \
  --environment "Variables={ENV_VAR1=value1,ENV_VAR2=value2}"

Step 10: Test the Lambda function

• Invoke the Lambda function to test its functionality.

aws lambda invoke --function-name my-lambda-function response.json

• Check the response.json file for the function's output.

Step 11: Update the Lambda function (if needed)

• If you make changes to your Lambda function code or environment variables, rebuild the Docker image, push it to Amazon ECR, and update the function using the AWS CLI.

docker build \
  --platform linux/amd64 \
  --tag your-account-id.dkr.ecr.your-region.amazonaws.com/my-lambda-function:latest .

docker push your-account-id.dkr.ecr.your-region.amazonaws.com/my-lambda-function:latest

aws lambda update-function-code \
  --function-name my-lambda-function \
  --image-uri your-account-id.dkr.ecr.your-region.amazonaws.com/my-lambda-function:latest

aws lambda update-function-configuration \
 --function-name my-lambda-function \
 --environment "Variables={ENV_VAR1=value1,ENV_VAR2=value2}"

Remember to replace your-region, your-account-id, and other placeholders with your actual AWS region, account ID, and other relevant information. Also, ensure that you have the necessary IAM permissions and follow best practices for securing your Lambda function and associated resources.