# Airgap Installation Guide for AtlasOS

## Overview

AtlasOS installer supports airgap (offline) installation for data centers without internet access. All required packages and dependencies are bundled into a single directory that can be transferred to the airgap system.

## Quick Start

### Step 1: Download Bundle (On System with Internet)

On a system with internet access and Ubuntu 24.04:

```bash
# Clone the repository
git clone <repository-url>
cd atlas

# Run bundle downloader (requires root)
sudo ./installer/bundle-downloader.sh ./atlas-bundle
```

This will create a directory `./atlas-bundle` containing:
- All required .deb packages (~100-200 packages)
- All dependencies
- Go binary (fallback)
- Manifest and README files

**Estimated bundle size:** 500MB - 1GB

### Step 2: Transfer Bundle to Airgap System

Transfer the entire bundle directory to your airgap system using:
- USB drive
- Internal network (if available)
- Physical media

```bash
# Example: Copy to USB drive
cp -r ./atlas-bundle /media/usb/

# On airgap system: Copy from USB
cp -r /media/usb/atlas-bundle /tmp/
```

### Step 3: Install on Airgap System

On the airgap system (Ubuntu 24.04):

```bash
# Navigate to bundle directory
cd /tmp/atlas-bundle

# Run installer with offline bundle
cd /path/to/atlas
sudo ./installer/install.sh --offline-bundle /tmp/atlas-bundle
```

## Bundle Contents

The bundle includes:

### Main Packages
- **Build Tools**: build-essential, git, curl, wget
- **ZFS**: zfsutils-linux, zfs-zed, zfs-initramfs
- **Storage Services**: samba, samba-common-bin, nfs-kernel-server, rpcbind
- **iSCSI**: targetcli-fb
- **Database**: sqlite3, libsqlite3-dev
- **Go Compiler**: golang-go
- **Utilities**: openssl, net-tools, iproute2

### Dependencies
All transitive dependencies are automatically included.

## Verification

Before transferring, verify the bundle:

```bash
# Count .deb files (should be 100-200)
find ./atlas-bundle -name "*.deb" | wc -l

# Check manifest
cat ./atlas-bundle/MANIFEST.txt

# Check total size
du -sh ./atlas-bundle
```

## Troubleshooting

### Missing Dependencies

If installation fails with dependency errors:

1. Ensure all .deb files are present in bundle
2. Check that bundle was created on Ubuntu 24.04
3. Verify system architecture matches (amd64/arm64)

### Go Installation Issues

If Go is not found after installation:

1. Check if `golang-go` package is installed: `dpkg -l | grep golang-go`
2. If missing, the bundle includes `go.tar.gz` as fallback
3. Installer will automatically extract it if needed

### Package Conflicts

If you encounter package conflicts:

```bash
# Fix broken packages
sudo apt-get install -f -y

# Or manually install specific packages
sudo dpkg -i /path/to/bundle/*.deb
sudo apt-get install -f -y
```

## Bundle Maintenance

### Updating Bundle

To update the bundle with newer packages:

1. Run `./installer/bundle-downloader.sh` again on internet-connected system
2. This will download latest versions
3. Transfer new bundle to airgap system

### Bundle Size Optimization

To reduce bundle size (optional):

```bash
# Remove unnecessary packages (be careful!)
# Only remove if you're certain they're not needed
```

## Security Considerations

- Verify bundle integrity before transferring
- Use secure transfer methods (encrypted USB, secure network)
- Keep bundle in secure location on airgap system
- Verify package signatures if possible

## Advanced Usage

### Custom Bundle Location

```bash
# Download to custom location
sudo ./installer/bundle-downloader.sh /opt/atlas-bundles/ubuntu24.04

# Install from custom location
sudo ./installer/install.sh --offline-bundle /opt/atlas-bundles/ubuntu24.04
```

### Partial Bundle (if some packages already installed)

If some packages are already installed on airgap system:

```bash
# Installer will skip already-installed packages
# Missing packages will be installed from bundle
sudo ./installer/install.sh --offline-bundle /path/to/bundle
```

## Support

For issues with airgap installation:
1. Check installation logs
2. Verify bundle completeness
3. Ensure Ubuntu 24.04 compatibility
4. Review MANIFEST.txt for package list