Ubuntu User Setup Script

create_user.sh · 6.0 KiB · Bash Raw

#!/bin/bash

# Ubuntu User Setup Script
# Creates user account, sets up SSH keys from GitHub, and optionally grants sudo privileges
# Must be run as root

set -e  # Exit on any error

# Color codes for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Function to print colored output
print_status() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

print_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

print_question() {
    echo -e "${BLUE}[QUESTION]${NC} $1"
}

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

# Check if required tools are available
if ! command -v curl &> /dev/null; then
    print_error "curl is required but not installed. Please install it first: apt update && apt install curl"
    exit 1
fi

print_status "Starting Ubuntu User Setup Script"
echo "=================================="
echo

# Step 1: Ask for username
while true; do
    print_question "Enter the username for the new user account:"
    read -r USERNAME
    
    if [[ -z "$USERNAME" ]]; then
        print_warning "Username cannot be empty. Please try again."
        continue
    fi
    
    if [[ ! "$USERNAME" =~ ^[a-z_]([a-z0-9_-]{0,31}|[a-z0-9_-]{0,30}\$)$ ]]; then
        print_warning "Invalid username format. Please use lowercase letters, numbers, hyphens and underscores only."
        continue
    fi
    
    break
done

# Step 2: Create user account if it doesn't exist
if id "$USERNAME" &>/dev/null; then
    print_warning "User '$USERNAME' already exists. Skipping user creation."
else
    print_status "Creating user account '$USERNAME'..."
    useradd -m -s /bin/bash "$USERNAME"
    print_status "User '$USERNAME' created successfully with home directory."
fi

# Get user's home directory
USER_HOME=$(eval echo "~$USERNAME")

# Step 3: Ask for GitHub username
while true; do
    print_question "Enter the GitHub username to fetch SSH keys from:"
    read -r GITHUB_USER
    
    if [[ -z "$GITHUB_USER" ]]; then
        print_warning "GitHub username cannot be empty. Please try again."
        continue
    fi
    
    # Validate GitHub user exists
    print_status "Validating GitHub user '$GITHUB_USER'..."
    HTTP_STATUS=$(curl -s -o /dev/null -w "%{http_code}" "https://api.github.com/users/$GITHUB_USER")
    
    if [[ "$HTTP_STATUS" == "200" ]]; then
        print_status "GitHub user '$GITHUB_USER' found."
        break
    elif [[ "$HTTP_STATUS" == "404" ]]; then
        print_warning "GitHub user '$GITHUB_USER' not found. Please check the username and try again."
        continue
    else
        print_warning "Unable to validate GitHub user (HTTP $HTTP_STATUS). Please check your internet connection and try again."
        continue
    fi
done

# Step 4: Download and setup SSH keys
print_status "Downloading SSH keys for GitHub user '$GITHUB_USER'..."

# Create .ssh directory with correct permissions
SSH_DIR="$USER_HOME/.ssh"
mkdir -p "$SSH_DIR"
chmod 700 "$SSH_DIR"

# Download SSH keys from GitHub
KEYS_URL="https://github.com/$GITHUB_USER.keys"
AUTHORIZED_KEYS_FILE="$SSH_DIR/authorized_keys"

# Download keys and check if any were found
KEYS_CONTENT=$(curl -s "$KEYS_URL")

if [[ -z "$KEYS_CONTENT" ]] || [[ "$KEYS_CONTENT" == "Not Found" ]]; then
    print_warning "No public SSH keys found for GitHub user '$GITHUB_USER'."
    print_warning "The user will need to add SSH keys manually or use password authentication."
    # Create empty authorized_keys file
    touch "$AUTHORIZED_KEYS_FILE"
else
    # Write keys to authorized_keys file (overwrites existing content)
    echo "$KEYS_CONTENT" > "$AUTHORIZED_KEYS_FILE"
    KEY_COUNT=$(echo "$KEYS_CONTENT" | wc -l)
    print_status "Successfully downloaded and installed $KEY_COUNT SSH key(s) for user '$USERNAME'."
fi

# Set correct permissions for SSH files
chmod 600 "$AUTHORIZED_KEYS_FILE"
chown -R "$USERNAME:$USERNAME" "$SSH_DIR"

# Step 5: Ask about sudo privileges
echo
while true; do
    print_question "Should user '$USERNAME' get sudo privileges? (y/N):"
    read -r GRANT_SUDO
    
    case $GRANT_SUDO in
        [Yy]|[Yy][Ee][Ss])
            # Add user to sudo group
            print_status "Adding user '$USERNAME' to sudo group..."
            usermod -aG sudo "$USERNAME"
            
            # Create sudoers file
            SUDOERS_FILE="/etc/sudoers.d/$USERNAME"
            print_status "Creating sudoers configuration file..."
            echo "$USERNAME ALL=(ALL:ALL) NOPASSWD: ALL" > "$SUDOERS_FILE"
            chmod 440 "$SUDOERS_FILE"
            
            # Validate sudoers file
            if visudo -c -f "$SUDOERS_FILE"; then
                print_status "User '$USERNAME' granted sudo privileges with NOPASSWD."
            else
                print_error "Error in sudoers file configuration. Removing file..."
                rm -f "$SUDOERS_FILE"
                exit 1
            fi
            break
            ;;
        [Nn]|[Nn][Oo]|"")
            print_status "User '$USERNAME' will not have sudo privileges."
            break
            ;;
        *)
            print_warning "Please answer 'y' for yes or 'n' for no."
            ;;
    esac
done

# Step 6: Summary
echo
print_status "Setup completed successfully!"
echo "=================================="
echo "Summary:"
echo "- User: $USERNAME"
echo "- Home directory: $USER_HOME"
echo "- SSH directory: $SSH_DIR (permissions: 700)"
echo "- SSH keys source: GitHub user '$GITHUB_USER'"
if [[ -n "$KEYS_CONTENT" ]] && [[ "$KEYS_CONTENT" != "Not Found" ]]; then
    echo "- SSH keys: $(echo "$KEYS_CONTENT" | wc -l) key(s) installed"
else
    echo "- SSH keys: No keys found (manual setup required)"
fi
echo "- Sudo privileges: $(if [[ "$GRANT_SUDO" =~ ^[Yy] ]]; then echo "Yes (NOPASSWD)"; else echo "No"; fi)"
echo
print_status "The user '$USERNAME' can now connect via SSH using their GitHub SSH keys."

if [[ "$GRANT_SUDO" =~ ^[Yy] ]]; then
    print_status "The user has passwordless sudo access."
fi

echo
print_status "Setup script finished."

1	#!/bin/bash
2
3	# Ubuntu User Setup Script
4	# Creates user account, sets up SSH keys from GitHub, and optionally grants sudo privileges
5	# Must be run as root
6
7	set -e # Exit on any error
8
9	# Color codes for output
10	RED='\033[0;31m'
11	GREEN='\033[0;32m'
12	YELLOW='\033[1;33m'
13	BLUE='\033[0;34m'
14	NC='\033[0m' # No Color
15
16	# Function to print colored output
17	print_status() {
18	echo -e "${GREEN}[INFO]${NC} $1"
19	}
20
21	print_warning() {
22	echo -e "${YELLOW}[WARNING]${NC} $1"
23	}
24
25	print_error() {
26	echo -e "${RED}[ERROR]${NC} $1"
27	}
28
29	print_question() {
30	echo -e "${BLUE}[QUESTION]${NC} $1"
31	}
32
33	# Check if running as root
34	if [[ $EUID -ne 0 ]]; then
35	print_error "This script must be run as root"
36	exit 1
37	fi
38
39	# Check if required tools are available
40	if ! command -v curl &> /dev/null; then
41	print_error "curl is required but not installed. Please install it first: apt update && apt install curl"
42	exit 1
43	fi
44
45	print_status "Starting Ubuntu User Setup Script"
46	echo "=================================="
47	echo
48
49	# Step 1: Ask for username
50	while true; do
51	print_question "Enter the username for the new user account:"
52	read -r USERNAME
53
54	if [[ -z "$USERNAME" ]]; then
55	print_warning "Username cannot be empty. Please try again."
56	continue
57	fi
58
59	if [[ ! "$USERNAME" =~ ^[a-z_]([a-z0-9_-]{0,31}\|[a-z0-9_-]{0,30}\$)$ ]]; then
60	print_warning "Invalid username format. Please use lowercase letters, numbers, hyphens and underscores only."
61	continue
62	fi
63
64	break
65	done
66
67	# Step 2: Create user account if it doesn't exist
68	if id "$USERNAME" &>/dev/null; then
69	print_warning "User '$USERNAME' already exists. Skipping user creation."
70	else
71	print_status "Creating user account '$USERNAME'..."
72	useradd -m -s /bin/bash "$USERNAME"
73	print_status "User '$USERNAME' created successfully with home directory."
74	fi
75
76	# Get user's home directory
77	USER_HOME=$(eval echo "~$USERNAME")
78
79	# Step 3: Ask for GitHub username
80	while true; do
81	print_question "Enter the GitHub username to fetch SSH keys from:"
82	read -r GITHUB_USER
83
84	if [[ -z "$GITHUB_USER" ]]; then
85	print_warning "GitHub username cannot be empty. Please try again."
86	continue
87	fi
88
89	# Validate GitHub user exists
90	print_status "Validating GitHub user '$GITHUB_USER'..."
91	HTTP_STATUS=$(curl -s -o /dev/null -w "%{http_code}" "https://api.github.com/users/$GITHUB_USER")
92
93	if [[ "$HTTP_STATUS" == "200" ]]; then
94	print_status "GitHub user '$GITHUB_USER' found."
95	break
96	elif [[ "$HTTP_STATUS" == "404" ]]; then
97	print_warning "GitHub user '$GITHUB_USER' not found. Please check the username and try again."
98	continue
99	else
100	print_warning "Unable to validate GitHub user (HTTP $HTTP_STATUS). Please check your internet connection and try again."
101	continue
102	fi
103	done
104
105	# Step 4: Download and setup SSH keys
106	print_status "Downloading SSH keys for GitHub user '$GITHUB_USER'..."
107
108	# Create .ssh directory with correct permissions
109	SSH_DIR="$USER_HOME/.ssh"
110	mkdir -p "$SSH_DIR"
111	chmod 700 "$SSH_DIR"
112
113	# Download SSH keys from GitHub
114	KEYS_URL="https://github.com/$GITHUB_USER.keys"
115	AUTHORIZED_KEYS_FILE="$SSH_DIR/authorized_keys"
116
117	# Download keys and check if any were found
118	KEYS_CONTENT=$(curl -s "$KEYS_URL")
119
120	if [[ -z "$KEYS_CONTENT" ]] \|\| [[ "$KEYS_CONTENT" == "Not Found" ]]; then
121	print_warning "No public SSH keys found for GitHub user '$GITHUB_USER'."
122	print_warning "The user will need to add SSH keys manually or use password authentication."
123	# Create empty authorized_keys file
124	touch "$AUTHORIZED_KEYS_FILE"
125	else
126	# Write keys to authorized_keys file (overwrites existing content)
127	echo "$KEYS_CONTENT" > "$AUTHORIZED_KEYS_FILE"
128	KEY_COUNT=$(echo "$KEYS_CONTENT" \| wc -l)
129	print_status "Successfully downloaded and installed $KEY_COUNT SSH key(s) for user '$USERNAME'."
130	fi
131
132	# Set correct permissions for SSH files
133	chmod 600 "$AUTHORIZED_KEYS_FILE"
134	chown -R "$USERNAME:$USERNAME" "$SSH_DIR"
135
136	# Step 5: Ask about sudo privileges
137	echo
138	while true; do
139	print_question "Should user '$USERNAME' get sudo privileges? (y/N):"
140	read -r GRANT_SUDO
141
142	case $GRANT_SUDO in
143	[Yy]\|[Yy][Ee][Ss])
144	# Add user to sudo group
145	print_status "Adding user '$USERNAME' to sudo group..."
146	usermod -aG sudo "$USERNAME"
147
148	# Create sudoers file
149	SUDOERS_FILE="/etc/sudoers.d/$USERNAME"
150	print_status "Creating sudoers configuration file..."
151	echo "$USERNAME ALL=(ALL:ALL) NOPASSWD: ALL" > "$SUDOERS_FILE"
152	chmod 440 "$SUDOERS_FILE"
153
154	# Validate sudoers file
155	if visudo -c -f "$SUDOERS_FILE"; then
156	print_status "User '$USERNAME' granted sudo privileges with NOPASSWD."
157	else
158	print_error "Error in sudoers file configuration. Removing file..."
159	rm -f "$SUDOERS_FILE"
160	exit 1
161	fi
162	break
163	;;
164	[Nn]\|[Nn][Oo]\|"")
165	print_status "User '$USERNAME' will not have sudo privileges."
166	break
167	;;
168	*)
169	print_warning "Please answer 'y' for yes or 'n' for no."
170	;;
171	esac
172	done
173
174	# Step 6: Summary
175	echo
176	print_status "Setup completed successfully!"
177	echo "=================================="
178	echo "Summary:"
179	echo "- User: $USERNAME"
180	echo "- Home directory: $USER_HOME"
181	echo "- SSH directory: $SSH_DIR (permissions: 700)"
182	echo "- SSH keys source: GitHub user '$GITHUB_USER'"
183	if [[ -n "$KEYS_CONTENT" ]] && [[ "$KEYS_CONTENT" != "Not Found" ]]; then
184	echo "- SSH keys: $(echo "$KEYS_CONTENT" \| wc -l) key(s) installed"
185	else
186	echo "- SSH keys: No keys found (manual setup required)"
187	fi
188	echo "- Sudo privileges: $(if [[ "$GRANT_SUDO" =~ ^[Yy] ]]; then echo "Yes (NOPASSWD)"; else echo "No"; fi)"
189	echo
190	print_status "The user '$USERNAME' can now connect via SSH using their GitHub SSH keys."
191
192	if [[ "$GRANT_SUDO" =~ ^[Yy] ]]; then
193	print_status "The user has passwordless sudo access."
194	fi
195
196	echo
197	print_status "Setup script finished."