handlr makes R functions available as API endpoints. It is the less opinionated cousin of OpenCPU.

• Built on Apache2 and rApache
• Each request handled in seperate R fork
• Borrows code e.g. for parsing http requests

• Doesn't expose your R code through GET requests
• You decide what R functions can be run
• Easy user management with authr

Assumes Ubuntu 16.04. See the wiki for a more thorough intro and authr for user management.

Install Apache2, rApache, and create an entry.R file that rApache will run:

sudo apt update
sudo apt install apache2 -y

sudo add-apt-repository ppa:opencpu/rapache -y
sudo apt-get update
sudo apt-get install libapache2-mod-r-base -y

sudo mkdir /var/www/R
sudo touch /var/www/R/entry.R
sudo vi /var/www/R/entry.R

Type i to insert then paste the following:

setHeader(header = "X-Powered-By", value = "rApache")

# functions exported by 'packages' can be used as endpoints
packages <- c('your_package')

handlr::handle(SERVER, GET, packages)

Save (type esc:wq then hit enter). Now create an example Apache2 site that will run entry.R for incomming http requests:

sudo touch /etc/apache2/sites-available/example.conf
sudo vi /etc/apache2/sites-available/example.conf

Type i to insert, then paste the following:

LoadModule R_module /usr/lib/apache2/modules/mod_R.so

<Location /api>
	SetHandler r-handler
	RFileHandler /var/www/R/entry.R
</Location>

Enable the example site:

sudo a2ensite example
sudo service apache2 reload

Save and exit as before. Install handlr and your_package, making sure they will be available to the www-data user that Apache2 runs under:

# devtools dependencies
sudo apt install libssl-dev 
sudo apt install libcurl4-openssl-dev

sudo R
.libPaths('/usr/local/lib/R/site-library')

install.packages('sys', configure.vars = 'NO_APPARMOR=1')
install.packages('devtools')

devtools::install_github(c('alexvpickering/handlr', 'your_github_username/your_package'))