🔧 CoreOS Diagnostics ISO Builder

This project builds a bootable Fedora CoreOS ISO that:

• Runs a container on startup to collect hardware & network diagnostics.
• Serves the results as YAML over HTTP (port 80).
• Displays them on the TTY console.
• Launches nmtui for manual networking if needed.
• Allows shell access for advanced inspection.

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📦 What It Does

• Embeds a podman-based container into a Fedora CoreOS ISO.
• Mounts the ISO during boot and loads the container directly.
• Gathers facts like:
  • Network interfaces
  • IP & MAC addresses
  • Disk types: nvme, ssd, hdd (filtered only)
• Starts an embedded HTTP server to serve /var/facts.yaml.

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📦 Containerized Version

curl -o coreos.live.x86_64.iso https://mirror.openshift.com/pub/openshift-v4/x86_64/dependencies/rhcos/latest/rhcos-live.x86_64.iso
podman pull quay.io/dds/discovery-iso:latest
podman run --rm --interactive \
  --security-opt label=disable \
  --volume "$PWD":/work/host \
  --workdir /work \
  -e HOME="/work" \
  quay.io/dds/discovery-iso:latest -c './create-iso.sh'

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🚀 Quick Start

1. 🧰 Install Required Tools

You’ll need the following on your build system:

sudo dnf install podman butane genisoimage xorriso curl -y

2. 🛠 Build the ISO

chmod +x create-iso.sh
./create-iso.sh

This script will:

• Build the diagnostic container
• Embed Ignition into the ISO
• Inject the container image
• Rebuild the bootable ISO as coreos-diagnostic-final.iso

It also copies the final ISO to:

/var/lib/libvirt/images/coreos-diagnostic.iso

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💻 Booting the ISO

You can boot the ISO:

• In a VM (via libvirt or virt-manager)
• On bare metal (USB/DVD)
• In PXE environments (with modifications)

On boot:

• Diagnostics are logged to /var/boot-diag.log
• Results are shown on the terminal
• nmtui is launched for manual networking
• A web server starts on port 80 to serve /var/facts.yaml

🐚 Shell Access

After you exit nmtui, you are dropped to a shell. From there:

• You can manually inspect logs, run commands, or test the network.
• When you exit the shell, the diagnostics summary will be re-displayed automatically.

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🌐 Fetching Diagnostics via Web

Once the ISO has booted and networking is active:

curl http://<diagnostic-node-ip>/

You’ll get a clean YAML output like:

network_interfaces:
  - name: eth0
    mac_address: aa:bb:cc:dd:ee:ff
    ip_address: 192.168.1.10/24
disks:
  - path: /dev/nvme0n1
    size: 512G
    type: nvme
    model: Samsung SSD

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🔍 Debug Tips

• View boot logs in emergency shell:

  journalctl -xb

• Check if container loaded:

  journalctl -u container-diagnostic.service

• If the web server isn't responding, verify:
  • Network is up
  • Port 80 is not blocked
  • The container is running

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📂 Files Created

File	Purpose
coreos-diagnostic.oci	Diagnostic container image
coreos-diagnostic.iso	ISO with embedded Ignition
coreos-diagnostic-final.iso	Final ISO with overlay
facts.yaml (inside VM)	Collected diagnostics
boot-diag.log (inside VM)	Boot-time logs from the script

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📝 Customization

Edit the gather_facts.sh section in create-iso.sh to add or modify:

• More hardware checks
• More metadata collection
• Output formats (e.g. JSON)

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📜 License

MIT License. Use freely, modify as needed.

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🙏 Acknowledgments

Built with ❤️ using:

• Fedora CoreOS
• Podman
• Butane & Ignition
• xorriso and mkisofs