Generate shell script to add 50 users into rocker/verse

add-50-rusers.R

# Generates a script ~/init_users.sh, which when run
# adds 50 users who can log into the Docker image running rocker/verse
# https://hub.docker.com/r/rocker/verse/

library(purrr)
library(stringr)

install.packages("glue")
library(glue)

1:50 %>%                                                                # Generate numbers 1, 2, 3, ..., 50, then
    map_chr(                                                            #   for each number (e.g. 1), map
        ~ str_pad(string = ., pad = "0", width = 2, side = "left") %>%  #     1        => "01"
            paste0("ruser", .) %>%                                      #    "01"      => "ruser01"
            glue(username = .,                                          #    "ruser01" => "useradd ... rstudio-server ruser01"
                 'useradd -m -c "{username}" {username} -s /bin/bash',
                 "; echo '{username}:{username}' | chpasswd",
                 "; usermod -a -G rstudio-server {username}"
            )
    ) %>%
    writeLines("~/init_users.sh")                                       # 'useradd -m -c "ruser01" ... rstudio-server ruser50'