rstats-base-httpuv

R/httpuv template for OpenFaaS with of-watchdog

Sends and receives JSON using httpuv and of-watchdog.

This template uses the rocker/r-base:latest image.

Making a new function

Use the faas-cli and pull R templates

faas-cli template pull https://github.com/analythium/openfaas-rstats-templates

Create a new function

faas-cli new --lang rstats-base-httpuv r-base-httpuv-hello --prefix=dockeruser

Customizing your function

Now we have a r-base-httpuv-hello.yml file and function folder ./r-base-httpuv-hello. Files in the function folder will get copied to the /home/app directory of the image. Read more about the YAML configuration. Customize the ./r-base-httpuv-hello/handler.R file as needed:

• load required packages using library(),
• put your data in the folder and load it relative to the function folder (e.g. data.RData) or use the full path (e.g. /home/app/data.csv),
• define the output given the input of the handle function, the output must be JSON parsable,
• add packages/remotes/system requirements and optionally metadata to the DESCRIPTION file.

Build, push, and deploy

The up command includes build (build an image into the local Docker library) push (push that image to a remote container registry), and deploy (deploy your function into a cluster):

faas-cli up -f r-base-httpuv-hello.yml

Testing

Test the local Docker image forwarding to port 4000

docker run -p 4000:8080 dockeruser/r-base-httpuv-hello

Curl should return ["Hello Friend!"]:

curl http://localhost:4000/ -d '["Friend"]'
# ["Hello Friend!"]

Use the OpenFaaS UI or curl (should give ["Hello Friend!"]). Replace localhost with IP address if testing on remote location:

curl http://localhost:8080/function/<function-name> -d '["Friend"]'
# ["Hello Friend!"]

Example: PCA

Create a new function:

faas-cli new --lang rstats-base-httpuv r-base-pca --prefix=dockeruser

Change handler.R:

suppressMessages({
  library(jsonlite)
  library(vegan)
})
handle <- function(req) {
  input <- req[["rook.input"]]
  postdata <- input$read_lines()
  x <- jsonlite::fromJSON(paste(postdata))
  output <- scores(rda(x), 1:2)$sites
  jsonlite::toJSON(output)
}

Edit DESCRIPTION:

Package: OpenFaaStR
Version: 0.0.1
Imports:
  jsonlite,
  vegan
Remotes:
SystemRequirements:
VersionedPackages:

Build the image: faas-cli build -f r-base-pca.yml and test with docker run -p 4000:8080 dockeruser/r-base-pca and

curl http://localhost:4000/ -H \
  "Content-Type: application/json" -d \
  '[[-1,3,16],[10,-10,9],[-5,10,-14],[14,3,-12]]'
# [[2.9545,3.042],[2.7754,-2.5023],[-3.4647,2.7223],[-2.2652,-3.262]]