A 1x1 pixel tracker and logger minimal example using plumber API in R

email_pixel_tracker.R

#This is a plumber api for setting up a basic pixel tracker
# here's a random page I found about what pixel trackers are: https://en.ryte.com/wiki/Tracking_Pixel
# When the pixel is loaded by an embedded image eg. 
#
# <img src="baseurl.com/pixel?log=this_is_the_message_I_want_to_log" >
#
# It creates a new folder for the date if needed then writes a log file into the folder

library(plumber)
library(png)
library(fs)
library(logger)

#* @apiTitle Pixel Tracker and Logger

#* Return a pixel
#* @param log Some identifier to be logged
#* @get /pixel
#* @serializer contentType list(type='image/png')
function(log=""){
  #generate a pixel
  pixel <- writePNG(matrix(1))
  
  #create a folder for the day
  log_dir <- paste0("logs/",Sys.Date())
  if (!fs::dir_exists(log_dir)) fs::dir_create(log_dir)
  log_appender(appender_tee(tempfile("pixel_tracker_", log_dir, ".log")))
  log_info(log)
  
  # return the pixel
  pixel
}