DEV Community

Janak Shrestha
Janak Shrestha

Posted on

Creating User Mohammed on App Server 3 in Stratos Datacenter

#linux

Creating User Mohammed on App Server 3 in Stratos Datacenter

Objective

This document outlines the procedure for creating a new user account on App Server 3 (stapp03) in the Stratos Datacenter. The system administration team has specified the following requirements:

  • Username: mohammed
  • UID: 1403
  • Home Directory: /opt/mohammed
  • Primary Group: nautilus_admin_users

Environment Details

  • Server: stapp03 (App Server 3)
  • Access User: banner
  • Access Password: BigGr33n
  • Sudo Privileges: Required

Implementation Methods

Method 1: One-Line Command Execution

Execute the following command from the jump host to create the user and group with a single command:

echo 'BigGr33n' | ssh banner@stapp03 "sudo -S bash -c 'groupadd nautilus_admin_users 2>/dev/null; useradd -u 1403 -d /opt/mohammed -m -g nautilus_admin_users mohammed 2>/dev/null; id mohammed; groups mohammed; ls -ld /opt/mohammed'"
Enter fullscreen mode Exit fullscreen mode

This command performs the following actions:

  • Creates the group nautilus_admin_users if it does not already exist
  • Creates the user mohammed with UID 1403, home directory /opt/mohammed, and sets nautilus_admin_users as the primary group
  • Displays verification information for the newly created user

Method 2: Heredoc Method

For a more comprehensive output with detailed verification, use the heredoc approach:

ssh banner@stapp03 << 'EOF'
echo 'BigGr33n' | sudo -S bash -c '
echo "Creating group nautilus_admin_users"
groupadd nautilus_admin_users 2>/dev/null || echo "Group already exists"

echo "Creating user mohammed"
useradd -u 1403 -d /opt/mohammed -m -g nautilus_admin_users mohammed 2>/dev/null || echo "User already exists"

echo "Verification Results:"
echo "User Details:"
id mohammed

echo "Home Directory:"
ls -ld /opt/mohammed

echo "Group Membership:"
groups mohammed

echo "User Entry in /etc/passwd:"
grep mohammed /etc/passwd

echo "Group Entry in /etc/group:"
grep nautilus_admin_users /etc/group
'
EOF
Enter fullscreen mode Exit fullscreen mode

Method 3: Interactive Session

For manual execution, connect to the server and perform the following commands:

# Connect to App Server 3
ssh banner@stapp03
# Enter password: BigGr33n

# Switch to root
sudo su -
# Enter password: BigGr33n

# Create the group
groupadd nautilus_admin_users

# Create the user with specified parameters
useradd -u 1403 -d /opt/mohammed -m -g nautilus_admin_users mohammed

# Verify the creation
id mohammed
ls -ld /opt/mohammed
groups mohammed
grep mohammed /etc/passwd
grep nautilus_admin_users /etc/group

# Exit
exit
exit
Enter fullscreen mode Exit fullscreen mode

Command Breakdown

The useradd command uses the following parameters:

  • -u 1403: Sets the user ID to 1403
  • -d /opt/mohammed: Specifies the home directory location
  • -m: Creates the home directory if it does not exist
  • -g nautilus_admin_users: Sets the primary group
  • mohammed: The username

Verification Procedures

After creating the user, verify the configuration using these commands:

# Verify user exists and UID is correct
id mohammed

# Verify home directory exists and ownership
ls -ld /opt/mohammed

# Verify group membership
groups mohammed

# Verify user entry in system files
grep mohammed /etc/passwd

# Verify group exists
getent group nautilus_admin_users
Enter fullscreen mode Exit fullscreen mode

Expected Output

Upon successful execution, the system should display:

uid=1403(mohammed) gid=1404(nautilus_admin_users) groups=1404(nautilus_admin_users)
drwx------ 2 mohammed nautilus_admin_users 4096 Jul 19 10:00 /opt/mohammed
mohammed : nautilus_admin_users
mohammed:x:1403:1404::/opt/mohammed:/bin/bash
nautilus_admin_users:x:1404:mohammed
Enter fullscreen mode Exit fullscreen mode

Alternative Approaches

Manual Home Directory Creation

If the home directory needs to be created separately:

mkdir -p /opt/mohammed
useradd -u 1403 -d /opt/mohammed -g nautilus_admin_users mohammed
chown mohammed:nautilus_admin_users /opt/mohammed
chmod 700 /opt/mohammed
Enter fullscreen mode Exit fullscreen mode

Modifying an Existing User

If the user already exists, update their configuration:

usermod -u 1403 -d /opt/mohammed -g nautilus_admin_users mohammed
mkdir -p /opt/mohammed
chown mohammed:nautilus_admin_users /opt/mohammed
Enter fullscreen mode Exit fullscreen mode

Setting User Shell

To specify a custom shell for the user:

useradd -u 1403 -d /opt/mohammed -m -g nautilus_admin_users -s /bin/bash mohammed
Enter fullscreen mode Exit fullscreen mode

Troubleshooting

User Already Exists

If the user already exists, modify the existing user account:

usermod -u 1403 -d /opt/mohammed -g nautilus_admin_users mohammed
mkdir -p /opt/mohammed
chown mohammed:nautilus_admin_users /opt/mohammed
Enter fullscreen mode Exit fullscreen mode

Group Already Exists

If the group already exists, proceed with user creation:

useradd -u 1403 -d /opt/mohammed -m -g nautilus_admin_users mohammed
Enter fullscreen mode Exit fullscreen mode

Permission Issues

Ensure proper sudo privileges:

sudo su -
# or use sudo with the command
sudo useradd -u 1403 -d /opt/mohammed -m -g nautilus_admin_users mohammed
Enter fullscreen mode Exit fullscreen mode

Invalid UID Error

Verify the UID is valid and not in use:

cut -d: -f3 /etc/passwd | sort -n
Enter fullscreen mode Exit fullscreen mode

Home Directory Not Created

Create and set permissions manually:

mkdir -p /opt/mohammed
chown mohammed:nautilus_admin_users /opt/mohammed
chmod 700 /opt/mohammed
Enter fullscreen mode Exit fullscreen mode

Security Considerations

After creating the user, consider implementing these additional security measures:

Set User Password 

passwd mohammed
Enter fullscreen mode Exit fullscreen mode

Configure Password Expiry 

chage -E 2027-12-31 mohammed
Enter fullscreen mode Exit fullscreen mode

Set Appropriate Home Directory Permissions 

chmod 700 /opt/mohammed
chown -R mohammed:nautilus_admin_users /opt/mohammed
Enter fullscreen mode Exit fullscreen mode

Restrict Shell Access

For service accounts, set a restricted shell:

usermod -s /sbin/nologin mohammed
Enter fullscreen mode Exit fullscreen mode

Automated Script

For repeatable deployments, save this as create_user.sh:

#!/bin/bash

echo "Creating User mohammed on App Server 3"

ssh banner@stapp03 << 'EOF'
echo 'BigGr33n' | sudo -S bash -c '
groupadd nautilus_admin_users 2>/dev/null
useradd -u 1403 -d /opt/mohammed -m -g nautilus_admin_users mohammed 2>/dev/null

echo "Verification Results:"
id mohammed
ls -ld /opt/mohammed
groups mohammed
grep mohammed /etc/passwd
grep nautilus_admin_users /etc/group
'
EOF
Enter fullscreen mode Exit fullscreen mode

Make the script executable and run:

chmod +x create_user.sh
./create_user.sh
Enter fullscreen mode Exit fullscreen mode

Summary

The user mohammed has been successfully created on App Server 3 (stapp03) in the Stratos Datacenter. The configuration includes:

  • Username: mohammed
  • UID: 1403
  • Home Directory: /opt/mohammed
  • Primary Group: nautilus_admin_users
  • Shell: /bin/bash (default)

The home directory has been created with appropriate ownership and permissions. The user is now ready for use on App Server 3 with all specified requirements satisfied. Verification commands confirm the user exists, the UID is correct, the home directory is properly configured, and the user is a member of the correct group.

Top comments (0)