Orchestra platform workshop pricing calculator

price_calculator.R

#' Workshop cost calculator
#' 
#' This cost calculator give the **minimum** cost for a workshop of the
#' requested size, number or participants, and hours. 
#'
#' @param vcpu numeric() amount of virtual cpu requested (can be fractional)
#' @param memory numeric() in GB the amount of requested memory
#' @param hours numeric() the number of hours for each instance to run
#'   The workshops will run for this amount of time even if a participant
#'   is not using it. So, every launch results in a cost. 
#' @param participants numeric() number of participants who launch a workshop
#' @param storage numeric() amount of disk storage requested
#' 
#' @seealso 
#'   * https://cloud.google.com/kubernetes-engine/docs/concepts/autopilot-resource-requests#min-max-requests
#'   * https://cloud.google.com/kubernetes-engine/pricing
#'  
price_per_session = function(
    vcpu=1, memory=2, hours=4, participants=20, storage=100
) {
  # account for memory/cpu ratio
  if(vcpu < 0.05) vcpu=0.05
  if(vcpu > 20) vcpu=20
  if(memory < 0.1) memory=0.1
  if(memory>=110) {
    stop("That amount of memory is not available.")
  }
  # account for memory/cpu ratio 
  # large memory will scale up vcpu
  final_vcpu = vcpu
  if(vcpu < memory/6) {
    final_vcpu=memory/6
    message(paste("vcpu request modified from", vcpu,"to", final_vcpu, "due to memory ratio."))
  }
  if(final_vcpu>30) {
    stop('Memory of vcpu request would result in compute resources not available.')
  }
  
  hours*participants*(final_vcpu*0.0455 + 0.0049225*memory+0.0001389*storage)
}