aws-lambda-r-runtime

This package makes it easy to run AWS Lambda Functions written in R.

Example

To run the example, we need to create a IAM role executing our lambda. This role should have the following properties:

• Trusted entity – Lambda.
• Permissions – AWSLambdaBasicExecutionRole.

Furthermore you need a current version of the AWS CLI.

Then create a lambda function which uses the R runtime layer:

cd example/
chmod 755 script.r
zip function.zip script.r
aws lambda create-function --function-name r-example \
    --zip-file fileb://function.zip --handler script.handler \
    --runtime provided --timeout 60 \
    --layers arn:aws:lambda:eu-central-1:131329294410:layer:r-runtime-3_5_1:1 \
    --role <role-arn> --region eu-central-1

The function simply increments 'x' by 1. Invoke the function:

aws lambda invoke --function-name r-example \
    --payload '{"x":1}' --region eu-central-1 response.txt
cat response.txt

The expected result should look similar to this:

{"result":2}

Using packages

We also provide a layer which ships with some recommended R packages, such as Matrix. This example lambda shows how to use them:

cd example/
chmod 755 matrix.r
zip function.zip matrix.r
aws lambda create-function --function-name r-matrix-example \
    --zip-file fileb://function.zip --handler matrix.handler \
    --runtime provided --timeout 60 --memory-size 3008 \
    --layers arn:aws:lambda:eu-central-1:131329294410:layer:r-runtime-3_5_1:1 \
        arn:aws:lambda:eu-central-1:131329294410:layer:r-recommended-3_5_1:1 \
    --role <role-arn> --region eu-central-1

The function returns the second column of some static matrix. Invoke the function:

aws lambda invoke --function-name r-matrix-example \
    --region eu-central-1 response.txt
cat response.txt

The expected result should look similar to this:

{"result":[4,5,6]}

Provided layers

Layers are only accessible in the AWS region they were published. We provide the following layers:

r-runtime

R, httr, jsonlite, aws.s3

Available AWS regions:

• ap-northeast-1
• ap-northeast-2
• ap-south-1
• ap-southeast-1
• ap-southeast-2
• ca-central-1
• eu-central-1
• eu-north-1
• eu-west-1
• eu-west-2
• eu-west-3
• sa-east-1
• us-east-1
• us-east-2
• us-west-1
• us-west-2

Available R versions:

• 3_5_1

ARN: arn:aws:lambda:${region}:131329294410:layer:r-runtime-${version}:1

r-recommended

The recommended packages that ship with R: boot, class, cluster, codetools, foreign, KernSmooth, lattice, MASS, Matrix, mgcv, nlme, nnet, rpart, spatial, survival

Available AWS regions:

• ap-northeast-1
• ap-northeast-2
• ap-south-1
• ap-southeast-1
• ap-southeast-2
• ca-central-1
• eu-central-1
• eu-north-1
• eu-west-1
• eu-west-2
• eu-west-3
• sa-east-1
• us-east-1
• us-east-2
• us-west-1
• us-west-2

Available R versions:

• 3_5_1

ARN: arn:aws:lambda:${region}:131329294410:layer:r-recommended-${version}:1

Documentation

The lambda handler is used to determine both the file name of the R script and the function to call. The handler must be separated by ., e.g., script.handler.

The lambda payload is unwrapped as named arguments to the R function to call, e.g., {"x":1} is unwrapped to handler(x=1).

The lambda function returns whatever is returned by the R function as a JSON object with result as a root element.

In order to install additional R packages, you can create a lambda layer containing the libraries, just as in the second example. The file structure must be R/library/<MY_LIBRARY>. See build_recommended.sh for an example. If your package requires system libraries, place them in R/lib/.

Limitations

AWS Lambda is limited to running with 3GB RAM and must finish within 15 minutes. It is therefore not feasible to execute long running R scripts with this runtime. Furthermore, only the /tmp/ directory is writeable on AWS Lambda. This must be considered when writing to the local disk.

Building

To build the layer yourself, you need to first build R from source. Start an EC2 instance which uses the Lambda AMI and run the build_r.sh script:

aws ec2 run-instances --image-id ami-657bd20a --count 1 --instance-type t2.micro --key-name <MyKeyPair>

You must pass the R version as a parameter to the script, e.g., 3.5.1. The script produces a zip containing a functional R installation in /opt/R/. Place this archive in the repository and run the build_runtime_and_publish.sh script. This creates a lambda layer named r-runtime in your AWS account. You can use it as shown in the example.