fedora-vm-builder

Ansible + OpenTofu builder for disposable Fedora VMs with kdump and kernel debuginfo pre-configured. Uses libvirt/KVM.

Prerequisites

• Linux host with libvirt/KVM (Fedora, RHEL, or CentOS Stream)
• Ansible (pip install ansible)
• OpenTofu (tofu in PATH)
• sshpass (for password-based SSH to the VM)

Quick Start

# Install Ansible dependencies
ansible-galaxy collection install -r requirements.yml

# Create a VM (default: Fedora 44, kdump enabled, debuginfo installed)
ansible-playbook 01-create-vm.yml

# SSH into the VM
~/vm-lab/work/fedora01_login.sh

# Capture a vmcore (inside the VM)
echo c | sudo tee /proc/sysrq-trigger

# After the VM reboots, retrieve the vmcore
scp fedora@<vm-ip>:/var/crash/*/vmcore .
scp fedora@<vm-ip>:/usr/lib/debug/lib/modules/$(ssh fedora@<vm-ip> uname -r)/vmlinux .

# Destroy everything
ansible-playbook 99-destroy-all.yml

Configuration

Edit vars.yml before running. Key settings:

Variable	Default	Description
vm_prefix	fedora01	Name prefix for libvirt resources
vm_os_image	Fedora 44 Cloud Base	Fedora cloud image URL (38–44 selectable)
vm_vcpu	2	vCPUs
vm_memory	4	RAM in GB
vm_disk_size	20	Disk in GB
vm_crashkernel	512M	crashkernel reservation
vm_install_debuginfo	true	Install kernel debuginfo at build time

What Gets Built

• libvirt storage pool (vm_prefix)
• NAT network with DHCP (vm_prefix_network)
• Fedora Cloud VM with:
  • User fedora / password fedora (sudo NOPASSWD)
  • kdump enabled with crashkernel=512M
  • kernel-debuginfo installed (vmlinux available)
  • Serial console + VNC

License

MIT