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Initial Host Setup Setting up a fresh Debian host from scratch 1 docs

Initial Host Setup

Description: Hardened setup for a fresh Debian host from zero to deployment.


1. System User & Privileges

We use the adam user for all administrative tasks. To minimize friction while maintaining security, we utilize SSH-key authentication and passwordless sudo via the wheel group.

Create the Admin User

# Create the user with a bash shell
useradd -m -s /bin/bash adam

# Create the wheel group (common for cross-distro consistency)
groupadd wheel

# Create a modular sudoers file with safety checks
# This allows members of 'wheel' to run sudo without a password
echo "%wheel ALL=(ALL) NOPASSWD: ALL" | sudo visudo -c -f /etc/sudoers.d/99-root-ermnvldmr

# Add adam to the necessary groups
usermod -aG wheel,docker adam


2. SSH Hardening & Key Management

Passwords are disabled. Access is strictly via SSH keys.

Secure SSH Directory

We set strict permissions immediately to prevent the SSH daemon from rejecting the keys.

# Setup directories as root for the adam user
mkdir -p /home/adam/.ssh
chmod 700 /home/adam/.ssh

# Add your public key (Replace [PASTE_PUB_KEY_HERE])
echo "[PASTE_PUB_KEY_HERE]" > /home/adam/.ssh/authorized_keys
chmod 600 /home/adam/.ssh/authorized_keys
chown -R adam:adam /home/adam/.ssh

Harden SSH Daemon

Modify the SSH configuration to change the default port and disable password entry.

# Create a dedicated override config
cat <<EOF > /etc/ssh/sshd_config.d/99-root-ermnvldmr.conf
Port 2222
PasswordAuthentication no
PermitEmptyPasswords no
AllowUsers adam
EOF

# Validate syntax before restarting to avoid lockout
sshd -t && systemctl restart ssh


3. GitHub Access (Deploy Key)

Since the repository is hosted on GitHub, the host needs its own identity to pull updates.

# Generate a host-specific SSH key (no passphrase for automation)
ssh-keygen -t ed25519 -f /home/adam/.ssh/adam-at-deytenit_github_com_ed25519 -N ""

# Display the public key to be added to GitHub (Settings > Deploy Keys)
cat /home/adam/.ssh/adam-at-deytenit_github_com_ed25519.pub

Tip

Add the output above to your GitHub Repository Deploy Keys with read access.


4. Install Docker Engine

Standard Docker installation for Debian - Docs: Docker - Install on Debian.

# Follow official guide: https://docs.docker.com/engine/install/debian/
# Once installed, verify (Adam can run this without sudo now)
docker run --rm hello-world


5. Repository Deployment

Clone the infrastructure repository and initialize the node.

# Setup the service directory
export REPO_DIR="/srv/root.ermnvldmr.com"
sudo mkdir -p $REPO_DIR
sudo chown adam:adam $REPO_DIR

# Clone as the adam user
sudo -u adam git clone git@github.com:deytenit/root.ermnvldmr.com.git $REPO_DIR

# Initialize node (Set your node name, e.g., daedalus)
export NODE="daedalus"
cd $REPO_DIR
sudo -u adam ./init.sh

Node-Specific Configuration

Run the staged initialization scripts in order:

# Run the sequence for your specific node
./$NODE/.host/.scripts/00-base
./$NODE/.host/.scripts/10-ufw
./$NODE/.host/.scripts/20-crowd
./$NODE/.host/.scripts/30-cron


6. Storage & Hardening

Define the data tiers and secure the environment by creating non-root users for containerized services.

# Create (or mount) storage directories
sudo mkdir -p /srv/com-ermnvldmr-root-$NODE-{tier1,tier2,tier3}

# Setup tiers and non-root users
sudo -u adam .scripts/ops/setup-tiers $NODE \
  /srv/com-ermnvldmr-root-$NODE-tier1 \
  /srv/com-ermnvldmr-root-$NODE-tier2 \
  /srv/com-ermnvldmr-root-$NODE-tier3

sudo -u adam .scripts/ops/setup-noroot-users $NODE