R/config.R

In curso-r/kuber: Automate cluster execution via Kubernetes

# Get gcloud configuration
#
# @description Checks gcloud's current configuration by running the
# `gcloud config list` command.
#
# @param quiet Whether to skip printing output (`FALSE` by default)
#
# @references \url{https://cloud.google.com/sdk/gcloud/reference/config/list}
#
# @return The string vector returned by the command
gcloud_get_config <- function(quiet = FALSE) {
  out <- sys("", "gcloud config list", print = FALSE, ignore.stderr = TRUE)
  if (!quiet) {
    cat(out, sep = "\n")
  }
  invisible(out)
}

# Set gcloud configuration
#
# @description Sets gcloud's current project and zone configs by running
# `gcloud config set project` and `gcloud config set compute/zone`.
#
# @param project The desired `[PROJECT_ID]` (or `NULL` to skip)
# @param zone The desired `[COMPUTE_ZONE]` (or `NULL` to skip)
# @param region The desired `[COMPUTE_REGION]` (or `NULL` to skip)
#
# @references \url{https://cloud.google.com/sdk/gcloud/reference/config/set}
#
# @return If everything has gone as expected, `TRUE`
gcloud_set_config <- function(project = NULL, zone = NULL, region = NULL) {
  if (!is.null(project)) {
    sys("Setting project", "gcloud config set project ", project)
  }
  if (!is.null(zone)) {
    sys("Setting zone", "gcloud config set compute/zone ", zone)
  }
  if (!is.null(region)) {
    sys("Setting region", "gcloud config set compute/region ", region)
  }
  invisible(TRUE)
}

#' Get bucket and image information from a kuber folder
#'
#' @description This function extracts the names of all important kuber
#' parameters stored in the `.kuber` hidden file.
#'
#' @param path Path to task directory (if missing, defaults to the most recently
#' created task)
#' @param what What parameter to return: `all`, `cluster`, `location`,
#' `region`, `num_nodes`, `bucket`, `image`, or `template`
#' @param quiet Whether to skip printing output (`FALSE` by default)
#'
#' @return A character vector with each parameter
#' @export
kub_get_config <- function(path, what = "all", quiet = FALSE) {
  path <- default_path(path)

  # Extract information
  lines <- readLines(paste0(path, "/.kuber"))

  # Get chosen parameter
  if (what != "all") {
    lines <- gsub(paste0(what, ": "), "", lines[grepl(what, lines)])
  }

  if (!quiet) {
    cat(lines, sep = "\n")
  }
  invisible(lines)
}

#' Set bucket and image information in a kuber directory
#'
#' @description This function sets the names of the docker image and of the
#' gcloud bucket in `job-tmpl.yaml` at a kuber folder.
#'
#' @param path Path to task directory (if missing, defaults to the most recently
#' created task)
#' @param parameters A list with parameters to change: `cluster`, `bucket`,
#' and/or `image` plus their respective values (or `NULL` to keep)
#'
#' @return If everything has gone as expected, `TRUE`
#' @export
kub_set_config <- function(path, parameters = list("cluster" = NULL, "bucket" = NULL, "image" = NULL)) {
  path <- default_path(path)

  # Read files
  config <- kub_get_config(path, quiet = TRUE)
  lines <- readLines(paste0(path, "/job-tmpl.yaml"))

  # Change settings
  if (!is.null(parameters$cluster)) {

    # Fetch cluster information
    cluster_name <- parameters$cluster
    cl <- cluster_info(cluster_name)

    config[1] <- paste("cluster:", cluster_name)
    config[2] <- paste("location:", cl$LOCATION)
    config[3] <- paste("region:", gsub("-[a-z]$", "", cl$LOCATION))
    config[4] <- paste("num_nodes:", cl$NUM_NODES)
  }
  if (!is.null(parameters$bucket)) {

    # Create bucket if necessary
    bucket_name <- parameters$bucket
    kub_create_bucket(bucket_name)

    lines[grep(" command: ", lines)] <- gsub(
      'ITEM", ".+"]', paste0('ITEM", "', bucket_name, '"]'),
      lines[grep(" command: ", lines)]
    )

    config[5] <- paste("bucket:", bucket_name)
  }
  if (!is.null(parameters$image)) {

    # Build image name if necessary
    image_name <- parameters$image
    if (!grepl("/", image_name)) {
      conf <- gcloud_get_config(TRUE)
      project <- gsub("project = ", "", conf[grep("project = ", conf)])
      image_name <- paste0("gcr.io/", project, "/", image_name, ":latest")
    }

    lines[grep(" image: ", lines)] <- gsub(
      ": .+", paste0(": ", image_name),
      lines[grep(" image: ", lines)]
    )
    config[6] <- paste("image:", image_name)
  }

  # Write files
  writeLines(lines, paste0(path, "/job-tmpl.yaml"))
  writeLines(config, paste0(path, "/.kuber"))

  invisible(TRUE)
}