Generate a number of users and directories in HDFS

mock_users.sh

USERNAMES=("aada" "aaro" "aino" "aleksi" "anni" "eeli" "eemil" "eetu" "eevi" "eino" "elias" "ella" "elsa" "emil" "enni" "helmi" "joona" "kerttu" "lauri" "leevi" "lenni" "lilja" "lotta" "luka" "lumi" "matias" "mikael" "mila" "nella" "niilo" "niklas" "olivia" "onni" "oona" "peetu" "pihla" "siiri" "veera" "veeti" "venla" "vilho" "vilma");

RAND_BASE=8;
RAND_POWER=3;
GROUP_NAME="demo";
DUMMY_FILE_SIZE=4096;
TMP_DUMMY_DIR="/tmp/dummy";

time_in_ms() { 
  date +"%s" 
} # time since the epoch in milliseconds

suffix() { 
  openssl rand -hex 3 
} # random 8 character string

rand_name() { 
  echo "$(time_in_ms)-$(suffix)" 
} # randomized file or directory name

rand_num() { 
  echo $[($RANDOM % $1) + 1] 
} # generate random integer

exp_scale() { 
  echo $1'^'$(rand_num 3) | bc 
} # generate an exponential number based on level

# Add group
sudo groupadd $GROUP_NAME; # tested
sudo mkdir -p $TMP_DUMMY_DIR;

for name in "${USERNAMES[@]}"
{
  # Create user
  sudo useradd -g $GROUP_NAME $name; # tested
  sudo usermod -g $GROUP_NAME $name; # tested - "usermod: no changes"
  user_dir="/user/$name"
  # Create user directory
  sudo -u hdfs hadoop fs -mkdir -p $user_dir; # tested
  # Make user the owner of user directory
  sudo -u hdfs hadoop fs -chown -R $name:$GROUP_NAME $user_dir; # tested
  number_of_dirs=$(exp_scale $(rand_num $RAND_BASE));
  for i in $(seq 1 $number_of_dirs)
  {
    dummy_dir=$user_dir'/'$(rand_name);
    sudo -u $name hadoop fs -mkdir -p $dummy_dir; # tested
    number_of_files=$(rand_num 4);
    # echo 'files '$number_of_files
    for f in $(seq 1 $number_of_files)
    {
      # Generate tmp dummy file
      dummy_file=$(rand_name)'.txt';
      dummy_local=$TMP_DUMMY_DIR'/'$dummy_file;
      head -c $DUMMY_FILE_SIZE /dev/urandom > $dummy_local;
      # Add file to HDFS
      sudo -u $name hadoop fs -put $dummy_local $dummy_dir'/'$dummy_file; # tested
    } # Files
  } # Directories
  echo $number_of_dirs' dirs created for '$name;
} # Users