Hi Enthusiast DevOps/SysOps Engineer,
Today we’ll be having a deep insight on the need to write an automated users bash script in an organization, and also having all the metrics and password auto generated stored in a LOG_FILE.
Before i proceed, the User bash script creation is in curtesy of (HNG Internship) program, which has just kicked off July 1st, to help various beginners and intermediate tech enthusiast in having a real world project experience. To learn more about HNG internship program, kindly visit
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Now lets delve to the business of the day,
Firstly, we’ll create a text file called (users) which is dependent on our bash script file to work.
light; sudo,dev,www-data
idimma; sudo
mayowa; dev,www-data
dmex; devops,sysops
iosegbo; sysops
Secondly we’ll be creating a file with create_users.sh which will run as our bash script file with the code below
Thirdly, we’ll have to assign an execution permission to the created bash script file chmod 700 create_users.sh
# Autogenerate Password and Metrics will be sent here
LOG_FILE=”/var/log/user_management.log”
PASSWORD_FILE=”/var/secure/user_passwords.txt”
# This will create a /var/secure file, and also assign a <write, read & execution> permission to the created file.
mkdir -p /var/secure
chmod 700 /var/secure
# Create or clear the log and password files
> $LOG_FILE
> $PASSWORD_FILE
chmod 600 $PASSWORD_FILE
# Function to generate random password
generate_password() {
echo $(openssl rand -base64 12)
}
# Read the input file, which is the <users> file we created to be dependent on our bash script code function execution
INPUT_FILE=$1
# Process each line in the file
while IFS= read -r line; do
# Ignore characters before the semicolon
after_semicolon=”${line#*;}”
# Split the line into items separated by commas
IFS=’,’ read -ra items <<< “$after_semicolon”
# Ensure a group exists for each item
for item in “${items[@]}”; do
item=$(echo “$item” | xargs) # Trim whitespace
if [ ! -z “$item” ]; then
if ! getent group “$item” > /dev/null; then
echo “Creating group: $item”
sudo groupadd “$item”
else
echo “Group already exists: $item”
fi
fi
done
done < “$INPUT_FILE”
# Process each line in the input file
while IFS=’;’ read -r user groups; do
# Trim whitespace
user=$(echo “$user” | xargs)
groups=$(echo “$groups” | xargs)
# Create user with home directory and primary group
if ! id “$user” &>/dev/null; then
useradd -m “$user”
echo “User $user was created successfully.” >> $LOG_FILE
else
echo “User $user already exists.” >> $LOG_FILE
fi
# Set user’s groups
if [ -n “$groups” ]; then
usermod -aG $groups “$user”
echo “User $user added to group: $groups.” >> $LOG_FILE
fi
# Auto Generate and set password
password=$(generate_password)
echo “$user:$password” | chpasswd
echo “$user,$password” >> $PASSWORD_FILE
echo “Password for user $user set.” >> $LOG_FILE
done < “$INPUT_FILE”
Lastly, here is the command to execute our bash script file sudo ./create_users.sh users, this command will execute the above bash script function which written as a code, enabling all the users to be assigned to the specified group and also enabling each users to have an assigned encrypted password which will be redirected or logged to a LOG_FILE encoded in the script.
Here are the list of cli to execute on our Linux VM to check the following output of our bash script block of code
sudo cat /var/log/user_management.log ( This cmd checks for the activities which has taken place in the course of the bash script execution called “MERTICS”).
sudo cat /var/secure/user_passwords.txt ( This cmd checks for the auto generate password assigned to each users under the created file.
Thank you for taking your time in reading through to the completion of the blog post, do have a wonderful time.
