### Theme: Space Exploration

#### Username: **astronaut**
#### Password: **stardust123** (Note: Use a strong password in a real setup)
#### Hostname: **spaceship**
#### Domain Name: **galaxy.local**

### Step-by-Step Opinionated Arch Linux Setup with Space Theme

#### Step 1: Verify Boot Mode
Ensure your system is booting in UEFI mode:
```bash
ls /sys/firmware/efi/efivars
```
If this directory exists, you are in UEFI mode.

#### Step 2: Partition the Disk
Format and mount the partitions:
```bash
mkfs.fat -F32 /dev/sda1  # EFI partition
mkswap /dev/sda2         # Swap partition
mkfs.ext4 /dev/sda3      # Root partition

mount /dev/sda3 /mnt
mkdir /mnt/boot
mount /dev/sda1 /mnt/boot
swapon /dev/sda2
```

#### Step 3: Install the Base System
Install the base packages:
```bash
pacstrap /mnt base linux linux-firmware vim
```

#### Step 4: Generate `fstab`
Generate the `fstab` file:
```bash
genfstab -U /mnt >> /mnt/etc/fstab
```

#### Step 5: Chroot into the New System
Change root into the new system:
```bash
arch-chroot /mnt
```

#### Step 6: Set Locale and Timezone
1. **Set locale**:
   - Edit `/etc/locale.gen` to uncomment your locale (e.g., `en_US.UTF-8`):
     ```bash
     vim /etc/locale.gen
     ```
   - Generate the locale:
     ```bash
     locale-gen
     ```

2. **Set timezone**:
   ```bash
   ln -sf /usr/share/zoneinfo/America/New_York /etc/localtime
   hwclock --systohc
   ```

#### Step 7: Set Hostname and Hosts
1. **Set hostname**:
   ```bash
   echo "spaceship.galaxy.local" > /etc/hostname
   ```

2. **Edit `/etc/hosts`**:
   ```bash
   vim /etc/hosts
   ```
   Add the following lines:
   ```
   127.0.0.1	localhost
   ::1		localhost
   127.0.1.1	spaceship.galaxy.local	spaceship
   ```

#### Step 8: Set Root Password
Set a strong password for the root user:
```bash
passwd
```
For this guide, we'll use `stardust123` as the root password.

#### Step 9: Create a Regular User Account
Create a user account and add it to the sudo group:
```bash
useradd -m astronaut
usermod -aG sudo astronaut
passwd astronaut
```
For this guide, we'll use `stardust123` as the user password.

#### Step 10: Install Bootloader
Install GRUB for UEFI:
```bash
pacman -S efibootmgr grub
grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=ArchLinux
grub-mkconfig -o /boot/grub/grub.cfg
```

#### Step 11: Exit Chroot and Reboot
Exit the chroot environment and reboot:
```bash
exit
umount -R /mnt
reboot
```

### Post-Installation Configuration

#### Step 12: Secure SSH
1. **Install SSH**:
   ```bash
   sudo pacman -S openssh
   ```

2. **Configure SSH**:
   - Open the SSH configuration file:
     ```bash
     sudo nano /etc/ssh/sshd_config
     ```
   - Make the following changes:
     - Change `PermitRootLogin` to `no`.
     - Change `PasswordAuthentication` to `no`.
     - Add `PubkeyAuthentication yes`.
     - Add `AuthorizedKeysFile .ssh/authorized_keys`.
   - Save the file and restart the SSH service:
     ```bash
     sudo systemctl enable sshd
     sudo systemctl start sshd
     ```

3. **Set Up SSH Keys**:
   - Generate an SSH key pair on your client machine:
     ```bash
     ssh-keygen -t rsa -b 4096
     ```
   - Copy the public key to your Arch Linux server:
     ```bash
     ssh-copy-id astronaut@your_server_ip
     ```

#### Step 13: Network Configuration
1. **Install NetworkManager**:
   ```bash
   sudo pacman -S networkmanager
   ```

2. **Enable NetworkManager**:
   ```bash
   sudo systemctl enable NetworkManager
   sudo systemctl start NetworkManager
   ```

3. **Configure DHCP for Ethernet**:
   - Ensure the interface `enp0s25` (or whatever your interface is named) is set to use DHCP:
     ```bash
     nmcli d
     nmcli con mod enp0s25 ipv4.method auto
     nmcli con up enp0s25
     ```

#### Step 14: Install a Minimal Desktop Environment (Optional)
If you want a minimal desktop environment, consider installing Xorg and a lightweight window manager like i3 or dwm.

1. **Install Xorg**:
   ```bash
   sudo pacman -S xorg-server xorg-xinit
   ```

2. **Install a Window Manager**:
   ```bash
   sudo pacman -S i3
   ```

3. **Configure Xinit**:
   - Create a `.xinitrc` file in your home directory:
     ```bash
     echo "exec i3" > ~/.xinitrc
     ```

4. **Start X**:
   ```bash
   startx
   ```

### Final Notes
- **Firewall**: Consider setting up a firewall using `ufw` or `firewalld`.
- **Regular Updates**: Regularly update your system using `sudo pacman -Syu`.
- **Backup**: Regularly back up important data.

This setup guide provides a secure, minimal, and opinionated configuration for Arch Linux with a fun space-themed scheme. Adjustments can be made based on your specific needs and preferences.