Automating User and Group Creation Using Bash script

Automating the creation of users and groups can help with administrative tasks and ensure adequate consistency across systems. This demonstrates how to create a Bash script that reads user and group information from a file and processes it accordingly….


This content originally appeared on DEV Community and was authored by Adebimpe peter

Automating the creation of users and groups can help with administrative tasks and ensure adequate consistency across systems. This demonstrates how to create a Bash script that reads user and group information from a file and processes it accordingly.

Below is a Bash script that reads from a file called users.txt, which contains usernames and groups, and then creates the users and groups on the system.

#!/bin/bash

# Check if running as root
if [[ $UID -ne 0 ]]; then
   echo "This script must be run as root"
   exit 1
fi

# Define the input file, log file, and secure password file
INPUT_FILE="$1"
LOG_FILE="/var/log/user_management.log"
PASSWORD_FILE="/var/secure/user_passwords.csv"

# Check if the input file was provided and exists
if [[ -z "$INPUT_FILE" ]]; then
   echo "No input file provided."
   exit 1
fi
if [[ ! -f "$INPUT_FILE" ]]; then
   echo "File $INPUT_FILE not found."
   exit 1
fi

# Create the log file and password file if they don't exist
touch "$LOG_FILE"
mkdir -p /var/secure
touch "$PASSWORD_FILE"

# Function to generate a random password
generate_password() {
  tr -dc A-Za-z0-9 </dev/urandom | head -c 12
}

# Function to log messages
log_message() {
  echo "$1" | tee -a "$LOG_FILE"
}

log_message "Backing up created files"
# Backup existing files
cp "$PASSWORD_FILE" "${PASSWORD_FILE}.bak"
cp "$LOG_FILE" "${LOG_FILE}.bak"

# Set permissions for password file
chmod 600 "$PASSWORD_FILE"

# Read the input file line by line
while IFS=';' read -r username groups || [[ -n "$username" ]]; do
   # Ignore whitespace
  username=$(echo "$username" | sed 's/ //g')
  groups=$(echo "$groups" | sed 's/ //g')

  # Parse the username and groups
  echo "$username"
  echo "$groups"

  # Create the user and their personal groups if they don't exist
  if id "$username" &>/dev/null; then
      log_message "User $username already exists. Skipping..."
  else
      # Create personal groups for the user
      groupadd "$username"
      # Create user with their personal groups
      useradd -m -s /bin/bash -g "$username" "$username"
      if [ $? -eq 0 ]; then
          log_message "User $username created with home directory."
      else
          log_message "Failed to create user $username."
          continue
      fi
      # Generate a random password and set it for the user
      PASSWORD=$(generate_password)
      echo "$username,$PASSWORD"
      if [ $? -eq 0 ]; then
          log_message "Password for user $username set."
      else
          log_message "Failed to set password for user $username."
      fi
      # Store the password securely
      echo "$username,$PASSWORD" >> "$PASSWORD_FILE"
      # Set the correct permissions for the home directory
      chmod 700 /home/"$username"
      chown "$username":"$username" /home/"$username"
      log_message "Home directory permissions set for user $username."
  fi

  # Add user to additional groups
  if [ -n "$groups" ]; then
      IFS=',' read -r -a groups_ARRAY <<< "$groups"
      for groups in "${groups_ARRAY[@]}"; do
          # Create groups if it doesn't exist
          if ! getent group "$groups" > /dev/null 2>&1; then
              groupadd "$groups"
              log_message "group $groups created."
          fi
          # Add user to the groups
          usermod -a -G "$groups" "$username"
          if [ $? -eq 0 ]; then
              log_message "User $username added to groups $groups."
          else
              log_message "Failed to add user $username to groups $groups."
          fi
      done
  fi
done < "$INPUT_FILE"
log_message "User creation process completed."

Breakdown of the script

Check if Running as Root:

if [[ $UID -ne 0 ]]; then
   echo "This script must be run as root"
   exit 1
fi

Define Input, Log, and Password Files:

INPUT_FILE="$1"
LOG_FILE="/var/log/user_management.log"
PASSWORD_FILE="/var/secure/user_passwords.csv"

Check if Input File Exists:

if [[ -z "$INPUT_FILE" ]]; then
   echo "No input file provided."
   exit 1
fi
if [[ ! -f "$INPUT_FILE" ]]; then
   echo "File $INPUT_FILE not found."
   exit 1
fi

Create Log and Password Files:

touch "$LOG_FILE"
mkdir -p /var/secure
touch "$PASSWORD_FILE"

Generate Random Password and log message functions:

generate_password() {
  tr -dc A-Za-z0-9 </dev/urandom | head -c 12
}

log_message() {
  echo "$1" | tee -a "$LOG_FILE"
}

Backup Existing Files:


log_message "Backing up created files"
cp "$PASSWORD_FILE" "${PASSWORD_FILE}.bak"
cp "$LOG_FILE" "${LOG_FILE}.bak"

Set Permissions for Password File:

chmod 600 "$PASSWORD_FILE"

Read Input File and Process Each Line:

while IFS=';' read -r username groups || [[ -n "$username" ]]; do
   username=$(echo "$username" | sed 's/ //g')
   groups=$(echo "$groups" | sed 's/ //g')

Create User and Groups:

if id "$username" &>/dev/null; then
    log_message "User $username already exists. Skipping..."
else
    groupadd "$username"
    useradd -m -s /bin/bash -g "$username" "$username"
    if [ $? -eq 0 ]; then
        log_message "User $username created with home directory."
    else
        log_message "Failed to create user $username."
        continue
    fi
    PASSWORD=$(generate_password)
    echo "$username,$PASSWORD"
    if [ $? -eq 0 ]; then
        log_message "Password for user $username set."
    else
        log_message "Failed to set password for user $username."
    fi
    echo "$username,$PASSWORD" >> "$PASSWORD_FILE"
    chmod 700 /home/"$username"
    chown "$username":"$username" /home/"$username"
    log_message "Home directory permissions set for user $username."
fi

Add User to Additional Groups:

if [ -n "$groups" ]; then
    IFS=',' read -r -a groups_ARRAY <<< "$groups"
    for groups in "${groups_ARRAY[@]}"; do
        if ! getent group "$groups" > /dev/null 2>&1; then
            groupadd "$groups"
            log_message "group $groups created."
        fi
        usermod -a -G "$groups" "$username"
        if [ $? -eq 0 ]; then
            log_message "User $username added to groups $groups."
        else
            log_message "Failed to add user $username to groups $groups."
        fi
    done
fi

Complete User Creation Process:

done < "$INPUT_FILE"
log_message "User creation process completed."

Example users.txt File
Here is an example of what the users.txt file might look like:

light; umanager,datadev,devops
tosingh; datadev,devops
peter; umanager

Running the Script

  1. Save the script to a file, e.g., create_users.sh.
  2. Ensure the script is executable
  3. Run the script with the input file as an argument 
chmod +x create_users.sh
sudo ./create_users.sh users.txt

After running , the password and log location should contain information needed.

you can learn more about this and so much more by registering on HNG


This content originally appeared on DEV Community and was authored by Adebimpe peter


Print Share Comment Cite Upload Translate Updates
APA

Adebimpe peter | Sciencx (2024-07-02T14:29:39+00:00) Automating User and Group Creation Using Bash script. Retrieved from https://www.scien.cx/2024/07/02/automating-user-and-group-creation-using-bash-script/

MLA
" » Automating User and Group Creation Using Bash script." Adebimpe peter | Sciencx - Tuesday July 2, 2024, https://www.scien.cx/2024/07/02/automating-user-and-group-creation-using-bash-script/
HARVARD
Adebimpe peter | Sciencx Tuesday July 2, 2024 » Automating User and Group Creation Using Bash script., viewed ,<https://www.scien.cx/2024/07/02/automating-user-and-group-creation-using-bash-script/>
VANCOUVER
Adebimpe peter | Sciencx - » Automating User and Group Creation Using Bash script. [Internet]. [Accessed ]. Available from: https://www.scien.cx/2024/07/02/automating-user-and-group-creation-using-bash-script/
CHICAGO
" » Automating User and Group Creation Using Bash script." Adebimpe peter | Sciencx - Accessed . https://www.scien.cx/2024/07/02/automating-user-and-group-creation-using-bash-script/
IEEE
" » Automating User and Group Creation Using Bash script." Adebimpe peter | Sciencx [Online]. Available: https://www.scien.cx/2024/07/02/automating-user-and-group-creation-using-bash-script/. [Accessed: ]
rf:citation
» Automating User and Group Creation Using Bash script | Adebimpe peter | Sciencx | https://www.scien.cx/2024/07/02/automating-user-and-group-creation-using-bash-script/ |

Please log in to upload a file.



There are no updates yet.
Click the Upload button above to add an update.

You must be logged in to translate posts. Please log in or register.

Related Posts