README.md

In dgrapov/ocpuclient: Utilities for interacting with an opencpu-server

Simple opencpu API client

Installation

install_github("dgrapov/ocpuclient")

Summary

The purpose of this package is to create drop in replacements for native library functions to instead call the libraries' opencpu endpoints. This can be used to create a scalable microservice infrastructure to support many functions diverse compute requirements while reducing client dependancy imports.

This package easily handles calls to functions with references to objects created in other calls or sessions. It is simple to use native httr to call opencpu functions but it is a whole other story if you want to reuse objects created in other session calls. This package is the culmination of a brute force effort to use httr, curl and crul to create a simple opencpu client.

Example

The following describes an example workflow for creating an opencpu client function for package foo_bar.

Native function in library foo_bar

#' @title foo
#' @export
foo<-function(...){
  paste0('That is ', ifelse(sample(c(FALSE,TRUE), size=1),'bar','foo'))
}

Client library foo_bar.client function for foo_bar::foo

#' @title ocpu_foo
#' @import ocpuclient
ocpu_foo  <- function(connection,
                     body = NULL,
                     pkg_url = 'ocpu/library/foo_bar/R/foo',
                     return_value =TRUE) {

  ocpu_post(
    connection,
    body = body,
    pkg_url = pkg_url,
    encode = 'json',
    return_value = return_value
  )

}

Use drop in replacement opencpu endpoint call

library(ocpuclient)

#establish connection to opencpu server

connection<-HttpClient$new(url = 'http://localhost/ocpu/') # see library::crul for all options

body<-list(arg1=1)

(results<-ocpu_foo(body=body))

Reference objects created in other opencpu session calls

body<-list(x=results)
(results<-ocpu_foo(body=body,pkg_url = 'ocpu/library/base/R/print',encode='form'))

Note, referencing objects created in previous sessions from R seems to require custom form encoding, see ocpuclient::format_crul_input for more details or use encode = NULL to passthrough custom encodings.

dgrapov/ocpuclient documentation built on April 16, 2022, 6:19 a.m.