README.md

AWS Lambda Client Package

aws.lambda is a simple client package for the Amazon Web Services (AWS) Lambda API.

To use the package, you will need an AWS account and to enter your credentials into R. Your keypair can be generated on the IAM Management Console under the heading Access Keys. Note that you only have access to your secret key once. After it is generated, you need to save it in a secure location. New keypairs can be generated at any time if yours has been lost, stolen, or forgotten. The aws.iam package profiles tools for working with IAM, including creating roles, users, groups, and credentials programmatically; it is not needed to use IAM credentials.

A detailed description of how credentials can be specified is provided at: https://github.com/cloudyr/aws.signature/. The easiest way is to simply set environment variables on the command line prior to starting R or via an Renviron.site or .Renviron file, which are used to set environment variables in R during startup (see ? Startup). They can be also set within R:

Sys.setenv("AWS_ACCESS_KEY_ID" = "mykey",
           "AWS_SECRET_ACCESS_KEY" = "mysecretkey",
           "AWS_DEFAULT_REGION" = "us-east-1",
           "AWS_SESSION_TOKEN" = "mytoken")

Code Examples

The package is still under rapid development, but a simple and literal "Hello, world!" example can be found by doing the following:

library("aws.lambda")

# get list of all current functions
funclist <- sapply(list_functions(), get_function_name)

# 'hello world!' example code
hello <- system.file("templates", "helloworld.js", package = "aws.lambda")

# get IAM role for Lambda execution
requireNamespace("aws.iam")
## Loading required namespace: aws.iam
id <- aws.iam::get_caller_identity()[["Account"]]
role <- paste0("arn:aws:iam::", id, ":role/lambda_basic_execution")

if (!"helloworld" %in% funclist) {
  func <- create_function(name = "helloworld", func = hello, 
                          handler = "helloworld.handler", role = role)
} else {
  func <- get_function("helloworld")
}

# invoke function
invoke_function(func)
## [1] "Hello, world!"

Obviously this is a trivial lambda function, but the point is that basically anything (in node.js, python, or java) could be written into the "deployment package" and called in this way.

A sligtly more complex example shows how to pass arguments to the lambda function via the function's payload and examine the response.

# example function that performs simple addition
plus <- system.file("templates", "plus.js", package = "aws.lambda")

# get IAM role for Lambda execution
requireNamespace("aws.iam")
id <- aws.iam::get_caller_identity()[["Account"]]
role <- paste0("arn:aws:iam::", id, ":role/lambda_basic_execution")

if (!"plus" %in% funclist) {
  func <- create_function(name = "plus", func = plus, 
                          handler = "plus.handler", role = role)
} else {
  func <- get_function("plus")
}

# invoke function
invoke_function(func, payload = list(a = 2, b = 3))
## [1] 5
invoke_function(func, payload = list(a = -5, b = 7))
## [1] 2

Installation

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This package is not yet on CRAN. To install the latest development version you can install from the cloudyr drat repository:

# latest stable version
install.packages("aws.s3", repos = c("cloudyr" = "http://cloudyr.github.io/drat"))

To install the latest development version from GitHub, run the following:

if (!require("ghit")){
    install.packages("ghit")
}
ghit::install_github("cloudyr/aws.lambda")

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cloudyr/aws.lambda documentation built on May 13, 2019, 8:19 p.m.