r2lambda

The goal of {r2lambda} is to make it easier to go from an R script to a deployed AWS Lambda function.

Requirements

• docker is required to build, tag, and push the image.
• An AWS account. build_lambda() already creates the ECR repository for the image, and deploy_lambda() creates an IAM role and the Lambda function.

Installation

You can install the development version of {r2lambda} like so:

# install.packages("remotes")
remotes::install_github("discindo/r2lambda")

Setup

r2lambda assumes credentials for connecting to AWS services are available in the R session. This can be done via an .Renviron file that should set environmental variables like so:

AWS_ACCESS_KEY_ID = "YOUR AWS ACCESS KEY ID"
AWS_SECRET_ACCESS_KEY = "YOUR AWS SECRET ACCESS KEY"
AWS_PROFILE = "YOUR AWS PROFILE"
AWS_REGION = "YOUR AWS REGION"

But since r2lambda uses paws under the hood, all authentication methods supported by paws are available in r2lambda. See here for details on setting credentials, region, profile, etc.

Workflow

Build a docker image for the lambda function

runtime_function <- "parity"
runtime_path <- system.file("parity.R", package = "r2lambda")
renvlock_path <- system.file("renv.lock", package = "r2lambda")
dependencies <- NULL

# Might take a while, its building a docker image
build_lambda(
  tag = "parity1",
  runtime_function = runtime_function,
  runtime_path = runtime_path,
  renvlock_path = renvlock_path,
  dependencies = dependencies
)

build_lambda() has a few more options:

• support_path: files or folders the runtime script needs. Each is copied next to the runtime script under its own name, so support_path = "R" lets the script call source("R/helpers.R").
• system_deps: Amazon Linux 2023 packages to install with dnf, for R packages that need system libraries, e.g. system_deps = "udunits2" for units. Amazon Linux 2023 has no EPEL, so some libraries, such as GDAL, are not available.
• architecture: "x86_64" (default) or "arm64". deploy_lambda() creates the function with the image’s architecture. Building for an architecture other than your machine’s needs Docker’s QEMU emulation.

Test the lambda docker image locally

payload <- list(number = 2)
tag <- "parity1"
test_lambda(tag = "parity1", payload)

Deploy to AWS Lambda

# Might take a while, its pushing it to a remote repository
deploy_lambda(tag = "parity1")

The function runs under a new IAM role with basic execution permissions. To let it call other AWS services, attach policies to that role, or use a role you already have:

deploy_lambda(
  tag = "parity1",
  policy_arns = "arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess"
)

deploy_lambda(tag = "parity1", role_arn = "arn:aws:iam::123456789012:role/my-role")

Inside the function, paws picks up the role’s temporary credentials, so no AWS keys go into the image or the function’s settings.

Invoke deployed lambda

invoke_lambda(
  function_name = "parity1",
  invocation_type = "RequestResponse",
  payload = list(number = 2),
  include_logs = FALSE
)

#> Lambda response payload:
#> {"parity":"even"}

Code of Conduct

Please note that the r2lambda project is released with a Contributor Code of Conduct. By contributing to this project, you agree to abide by its terms.