# Multi-Distribution Linux VM Deployment Cheatsheet

## Supported Distributions

### Debian Family
- Debian 11 (Bullseye)
- Debian 12 (Bookworm)
- Ubuntu 20.04 LTS (Focal)
- Ubuntu 22.04 LTS (Jammy)
- Ubuntu 24.04 LTS (Noble)

### RHEL Family
- RHEL 8, 9 (requires subscription)
- CentOS Stream 8, 9
- Rocky Linux 8, 9
- AlmaLinux 8, 9

### SUSE Family
- SLES 15 (requires subscription)
- openSUSE Leap 15.5, 15.6

## Quick Deployment

### Debian/Ubuntu

```bash
# Debian 12
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=debian-12" \
  -e "vm_name=debian12-vm"

# Ubuntu 22.04 LTS
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=ubuntu-22.04" \
  -e "vm_name=ubuntu22-vm"

# Ubuntu 24.04 LTS
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=ubuntu-24.04" \
  -e "vm_name=ubuntu24-vm"
```

### RHEL Family

```bash
# CentOS Stream 9
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=centos-stream-9" \
  -e "vm_name=centos9-vm"

# Rocky Linux 9
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=rocky-9" \
  -e "vm_name=rocky9-vm"

# AlmaLinux 9
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=almalinux-9" \
  -e "vm_name=alma9-vm"
```

### SUSE Family

```bash
# openSUSE Leap 15.6
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=opensuse-leap-15.6" \
  -e "vm_name=opensuse-vm"
```

## Custom Resource Allocation

```bash
# High-performance VM
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=rocky-9" \
  -e "vm_name=app-server" \
  -e "vm_vcpus=8" \
  -e "vm_memory_mb=16384" \
  -e "vm_disk_size_gb=100"

# Development VM
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=ubuntu-22.04" \
  -e "vm_name=dev-box" \
  -e "vm_vcpus=4" \
  -e "vm_memory_mb=8192" \
  -e "vm_disk_size_gb=50"

# Minimal VM
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=debian-12" \
  -e "vm_name=test-vm" \
  -e "vm_vcpus=1" \
  -e "vm_memory_mb=1024" \
  -e "vm_disk_size_gb=10"
```

## Custom Configuration

```bash
# Custom hostname and domain
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=centos-stream-9" \
  -e "vm_name=web-server" \
  -e "vm_hostname=webserver01" \
  -e "vm_domain=production.local"

# Custom SSH key
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=ubuntu-24.04" \
  -e "vm_name=secure-vm" \
  -e "ansible_user_ssh_key='ssh-ed25519 AAAA...'"

# Custom network
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=rocky-9" \
  -e "vm_name=isolated-vm" \
  -e "vm_network=isolated" \
  -e "vm_bridge=virbr1"
```

## Tag-Based Execution

```bash
# Pre-flight checks only
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=debian-12" \
  -t preflight,validate

# Download and verify image only
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=ubuntu-22.04" \
  -t download,verify

# Create storage only
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=rocky-9" \
  -e "vm_name=myvm" \
  -t storage

# Generate cloud-init config only
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=centos-stream-9" \
  -e "vm_name=myvm" \
  -t cloud-init

# Deploy VM (assumes image downloaded)
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=almalinux-9" \
  -e "vm_name=myvm" \
  -t deploy

# Validation only
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=debian-12" \
  -e "vm_name=myvm" \
  -t validate

# Cleanup temporary files
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=ubuntu-24.04" \
  -e "vm_name=myvm" \
  -t cleanup
```

## Required Variables

| Variable | Required | Default | Description |
|----------|----------|---------|-------------|
| `os_distribution` | **YES** | debian-12 | Distribution identifier |
| `vm_name` | No | linux-guest | VM name in libvirt |
| `vm_hostname` | No | linux-vm | VM hostname |
| `vm_domain` | No | localdomain | Domain name |
| `vm_vcpus` | No | 2 | Number of vCPUs |
| `vm_memory_mb` | No | 2048 | RAM in MB |
| `vm_disk_size_gb` | No | 20 | Disk size in GB |
| `vm_network` | No | default | Libvirt network |
| `ansible_user_ssh_key` | No | (predefined) | SSH public key |

## Distribution Identifiers

```
Debian:
  - debian-11
  - debian-12

Ubuntu:
  - ubuntu-20.04
  - ubuntu-22.04
  - ubuntu-24.04

RHEL Family:
  - rhel-8 (manual download)
  - rhel-9 (manual download)
  - centos-stream-8
  - centos-stream-9
  - rocky-8
  - rocky-9
  - almalinux-8
  - almalinux-9

SUSE Family:
  - sles-15 (manual download)
  - opensuse-leap-15.5
  - opensuse-leap-15.6
```

## Distribution-Specific Features

### Debian/Ubuntu
- Package Manager: `apt`
- Firewall: `ufw`
- Automatic Updates: `unattended-upgrades`
- User Group: `sudo`

### RHEL/CentOS/Rocky/Alma
- Package Manager: `dnf`
- Firewall: `firewalld`
- Automatic Updates: `dnf-automatic`
- SELinux: Enforcing mode
- User Group: `wheel`

### SUSE/openSUSE
- Package Manager: `zypper`
- Firewall: `firewalld`
- User Group: `wheel`

## Common Use Cases

### Deploy Database Server (Rocky Linux)
```bash
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=rocky-9" \
  -e "vm_name=db-server" \
  -e "vm_hostname=postgres01" \
  -e "vm_vcpus=4" \
  -e "vm_memory_mb=8192" \
  -e "vm_disk_size_gb=100"
```

### Deploy Web Server (Ubuntu)
```bash
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=ubuntu-22.04" \
  -e "vm_name=web-server" \
  -e "vm_hostname=nginx01" \
  -e "vm_vcpus=2" \
  -e "vm_memory_mb=4096" \
  -e "vm_disk_size_gb=40"
```

### Deploy Container Host (CentOS Stream)
```bash
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=centos-stream-9" \
  -e "vm_name=container-host" \
  -e "vm_hostname=podman01" \
  -e "vm_vcpus=6" \
  -e "vm_memory_mb=12288" \
  -e "vm_disk_size_gb=80"
```

### Deploy Development VM (Debian)
```bash
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=debian-12" \
  -e "vm_name=dev-vm" \
  -e "vm_hostname=devbox" \
  -e "vm_vcpus=4" \
  -e "vm_memory_mb=8192" \
  -e "vm_disk_size_gb=50"
```

## Post-Deployment

### Access VM

```bash
# Get VM IP
ssh grokbox "virsh domifaddr <vm_name>"

# SSH to VM
ssh -J grokbox ansible@<VM_IP>

# Add to ~/.ssh/config
Host myvm
    HostName <VM_IP>
    User ansible
    ProxyJump grokbox
    StrictHostKeyChecking accept-new
```

### VM Management

```bash
# Start/Stop
virsh start <vm_name>
virsh shutdown <vm_name>
virsh destroy <vm_name>

# Status
virsh dominfo <vm_name>
virsh list --all

# Autostart
virsh autostart <vm_name>
virsh autostart <vm_name> --disable

# Console access
virsh console <vm_name>
```

## Troubleshooting

### Cloud-Init Status
```bash
# On VM
cloud-init status
cloud-init status --wait
cloud-init status --long

# Logs
tail -f /var/log/cloud-init-output.log
journalctl -u cloud-init
```

### Network Issues
```bash
# Check IP assignment
virsh domifaddr <vm_name>

# Check libvirt network
virsh net-list
virsh net-dhcp-leases default

# Restart network (on hypervisor)
virsh net-destroy default
virsh net-start default
```

### SELinux Issues (RHEL Family)
```bash
# Check status
getenforce

# View denials
ausearch -m avc -ts recent

# Generate policy
audit2allow -a
```

### Firewall Issues

```bash
# Debian/Ubuntu
sudo ufw status verbose
sudo ufw allow <port>

# RHEL/SUSE
sudo firewall-cmd --list-all
sudo firewall-cmd --permanent --add-service=<service>
sudo firewall-cmd --reload
```

### Package Manager Issues

```bash
# Debian/Ubuntu
sudo apt update
sudo apt upgrade
sudo apt-cache search <package>

# RHEL/CentOS/Rocky/Alma
sudo dnf check-update
sudo dnf upgrade
sudo dnf search <package>

# SUSE/openSUSE
sudo zypper refresh
sudo zypper update
sudo zypper search <package>
```

## Image Cache Location

All downloaded cloud images are cached at:
```
/var/lib/libvirt/images/<distribution>-<version>-*-amd64.qcow2
```

To update cached images:
```bash
# Remove old image
ssh grokbox "rm /var/lib/libvirt/images/<image-name>.qcow2"

# Re-run playbook to download latest
ansible-playbook plays/deploy-linux-vm.yml \
  -e "os_distribution=<distro>" \
  -t download,verify
```

## Manual Download (RHEL/SLES)

For distributions requiring subscriptions:

1. **RHEL**: Download from Red Hat Customer Portal
   - Location: https://access.redhat.com/downloads/
   - Product: Red Hat Enterprise Linux
   - Type: KVM Guest Image

2. **SLES**: Download from SUSE Customer Center
   - Location: https://scc.suse.com/
   - Product: SUSE Linux Enterprise Server
   - Type: Cloud Image

3. Place downloaded image at:
   ```
   /var/lib/libvirt/images/<cache_name>
   ```

4. Run deployment playbook normally

## Security Features

All deployed VMs include:

✅ **User Management**
- ansible user with passwordless sudo
- SSH key-based authentication only
- Root login disabled via SSH

✅ **Firewall** (enabled and configured)
- Debian/Ubuntu: UFW
- RHEL/SUSE: firewalld

✅ **Automatic Updates**
- Debian/Ubuntu: unattended-upgrades
- RHEL: dnf-automatic
- Security updates only, no auto-reboot

✅ **Security Hardening**
- RHEL: SELinux enforcing
- Audit daemon enabled
- Secure SSH configuration
- Time synchronization (chrony)

✅ **Essential Packages**
- System tools: vim, htop, tmux
- Network tools: curl, wget, rsync
- Development: git, python3
- Security: aide, auditd

## Validation Checklist

After deployment:

- [ ] VM running: `virsh list | grep <vm_name>`
- [ ] IP assigned: `virsh domifaddr <vm_name>`
- [ ] SSH accessible: `ssh -J grokbox ansible@<IP>`
- [ ] Cloud-init complete: `cloud-init status`
- [ ] Firewall enabled: `sudo ufw status` or `sudo firewall-cmd --state`
- [ ] Updates configured: Check respective service
- [ ] SELinux enforcing (RHEL): `getenforce`
- [ ] Time sync: `chronyc tracking`
- [ ] Audit daemon: `systemctl status auditd`

## Quick Reference

### Deployment Workflow
1. **Validate** → Check distribution and VM name
2. **Install** → Install required packages on hypervisor
3. **Download** → Download distribution cloud image
4. **Verify** → Validate image checksums
5. **Storage** → Create VM disk from cloud image
6. **Cloud-Init** → Generate configuration for OS family
7. **Deploy** → Create and start VM with virt-install
8. **Validate** → Verify SSH and system status
9. **Cleanup** → Remove temporary files

### Important Paths
- Cloud Images: `/var/lib/libvirt/images/*.qcow2`
- VM Disks: `/var/lib/libvirt/images/<vm_name>.qcow2`
- Cloud-Init ISO: `/var/lib/libvirt/images/<vm_name>-cloud-init.iso`
- VM Config: `/etc/libvirt/qemu/<vm_name>.xml`

### Emergency Access

If SSH fails, use console:
```bash
virsh console <vm_name>

# Login as root with password: ChangeMe123!
# (Change this immediately!)
```

## Support

- Documentation: `docs/linux-vm-deployment.md`
- Playbook: `plays/deploy-linux-vm.yml`
- Guidelines: `CLAUDE.md`