Part of Smart-home security demo using AI - LLMs

Hydra provides an isolated environment to run containers. The isolated containers run in a single VMi managed by an instance of containerd. Csi-grpc-proxy is used to enable access to containerd via a TCP connection. It also provides a way to install crismux that enables kubelet to talk to multiple containerd instances. Each containerd is responsible for a runtime class in kubernetes. Default runtime class containers run in the containerd local to the node and nelly runtime class containers run inside the VM.

Hydra is composed by two separate modules: isolated-vm and add-crismux. Isolated-vm starts a VM with desired properties. Isolated-vm can be used as stand-alone by directly running start-vm.sh script on MacOS/Linux, as docker container or run using a helm chart. The second module install crismux in a k3s/k8s installation. It also installs a "nelly" runtime class. This runtime class will direct kubelet to use the isolated VM to run the container instead of running it on the host.

Isolated-vm VM utilizes KVM or HVF acceleration if available. The scripts run under MacOS, Linux, docker and k3s.

Requirements

Linux

- KVM
- wget
- mkisofs

MacOS

- Homebrew (strongly suggested)
- KVM
- wget

Docker

- docker installed on the host

K3s

- running installation of K3s (can be installed using k3sup)
- helm

Motivation

Usage

Helm (install both crismux and isolated-vm charts)

helm repo add hydra https://smarter-project.github.io/hydra/
helm install \
     --set "isolated-vm.configuration.sshkey=<public ssh key to use>" \
     <local name> hydra/hydra

isolated-vm.configuration.sshkey allows ssh login to VM

add

--set "configuration.local_node_image_dir="

to store images at the container and not on the node, because the container filesystem is not persistent, all files will be lost if the container is stopped.

Docker

Isolated-vm

TL;DR

docker run \
    -d \
    --rm \
    --network host \
    --env "VM_SSH_AUTHORIZED_KEY=\"$(cat <file with SSH public key>)\"" \
    -v <local image directory>:/root/image \
    -v /var/lib/kubelet:/var/lib/kubelet \
    -v /var/log/pods:/var/log/pods \
    --device /dev/kvm:/dev/kvm \
    isolated-vm

Update <file with SSH public key> and <local image directory> with the correct files. <local image directory> has to have a full path.

Details

The directory "image" located on the directory <local image directory>. The image will be downloaded and configured once and new runs will reuse the umage (much faster startup). A few variables of list below (user configuration, shared directories for example) if changed from when the image was first download will trigger a re-download of image. SSH will be availabe at port 5555 and Containerd CRI will be available at port 35000. A csi-proxy or crismux running on the host can be used to convert that port to a socket if required.

The image will be resized automatically according to the sizes provided. The image will not be reduced in size.

The VM will use acceleration if available.

THe following variables configures the script:

Variable	Usage	Default value
DRY_RUN_ONLY	If > 0 will print the command line for the VM and exit	0
DEBUG	If > 0 will print debug for the script	0
DISABLE_9P_KUBELET_MOUNTS	If > 0 do not enable mounting of /var/lib/kubelet and /var/lib/pods	0
ADDITIONAL_9P_MOUNTS	additional mounts format `	[$
COPY_IMAGE_BACKUP	if > 0 preserve a copy of the image and start form a copy of that image if it exists	0
ALWAYS_REUSE_DISK_IMAGE	if > 0 reuse existing disk image even if configuration has changed	0
DEFAULT_KERNEL_VERSION	kernel version to install	6.12.12+bpo
KERNEL_VERSION	full version to install if a different kernel is required	linux-image-${DEFAULT_KERNEL_VERSION}-${ARCH}
DEFAULT_DIR_IMAGE	Where to store the downloaded image	$(pwd)/image
DEFAULT_DIR_K3S_VAR_DARWIN	Where to point the 9p mounts if running on MacOS	$(pwd)/k3s-var
DEFAULT_DIR_K3S_VAR_LINUX_NON_ROOT	Where to point the 9p mounts if running on Linux as a non-root user	$(pwd)/k3s-var
DEFAULT_DIR_K3S_VAR_LINUX_ROOT	Where to point the 9p mounts if running on linux machine as root (or inside a container )
DEFAULT_DIR_K3S_VAR_OTHER	Where to point the 9p mounts if running on other OS machine	$(pwd)/k3s-var
DEFAULT_IMAGE	QCOW image to use as base	debian-12-genericcloud-${ARCH}-20250316-2053.qcow2
DEFAULT_SOURCE_IMAGE	where to download QCOW image	https://cloud.debian.org/images/cloud/bookworm/20250316-2053/
DEFAULT_DIR_IMAGE	Directory to use to store image and artifacts	$(pwd)/image
DEFAULT_KVM_DARWIN_CPU	# CPUS allocated to the VM when running in MacOS	2
DEFAULT_KVM_DARWIN_MEMORY	DRAM allocated to the VM to the VM when running in MacOS	2
DEFAULT_KVM_LINUX_CPU	# CPUS allocated to the VM when running in Linux/container	2
DEFAULT_KVM_LINUX_MEMORY	DRAM allocated to the VM to the VM when running in Linux/container	2
DEFAULT_KVM_UNKNOWN_CPU	# CPUS allocated to the VM when running in unknown OS	2
DEFAULT_KVM_UNKNOWN_MEMORY	DRAM allocated to the VM to the VM when running in unknown OS	2
DEFAULT_KVM_DISK_SIZE	Maximum size of QCOW disk	3
DEFAULT_KVM_DARWIN_BIOS	bios to boot (UEFI) when running under MacOS	/opt/homebrew/Cellar/qemu/9.2.2/share/qemu/edk2-${ARCH}-code.fd
DEFAULT_KVM_LINUX_v9_BIOS	bios to boot (UEFI) when running under Linux/container with KVM v9x
DEFAULT_KVM_LINUX_v7_BIOS	bios to boot (UEFI) when running under Linux/container with KVM v7x	/usr/share/qemu-efi-aarch64/QEMU_EFI.fd
DEFAULT_KVM_UNKNWON_BIOS	bios to boot (UEFI) when running under unknown OS
DEFAULT_KVM_HOST_SSHD_PORT	TCP port to be used on the host to access port 22 on VM	5555
DEFAULT_KVM_HOST_CONTAINERD_PORT	TCP port to be used on the host to access port 35000 (cs-grpc-proxy) on VM	35000
DEFAULT_CSI_GRPC_PROXY_URL	URL to get csi-grpc-proxy binary	https://github.com/democratic-csi/csi-grpc-proxy/releases/download/v0.5.6/csi-grpc-proxy-v0.5.6-linux-
KVM_CPU_TYPE	CPU type	Use "host" if accelerated, otherise use "cortex-a76" or "qemu64-v1"
KVM_CPU	# cpus to allocate	DEFAULT_KVM_<OS>_CPU
KVM_MEMORY	DRAM to allocate	DEFAULT_KVM_<OS>_MEMORY
KVM_BIOS	BIOS to use	DEFAULT_KVM_<OS>_BIOS
KVM_MACHINE_TYPE	KVM machine type	use "virt" or ""pc"
VM_USERNAME	Usename to created at VM	vm-user
VM_SALT	Salt to be used when creating the encrypted password	123456
VM_PASSWORD	Cleartext password to be used	vm-user
VM_PASSWORD_ENCRYPTED	Encrypted password to be used, overwrites the cleartext password
VM_HOSTNAME	Hostname	vm-host
VM_SSH_AUTHORIZED_KEY	ssh public key to add to authorized_key for the user VM_USERNAME
RUN_BARE_KERNEL	if > 0 then Use kernel and initrd instead of cloud image	0
DEFAULT_KVM_PORTS_REDIRECT	format is <external>:<internal>[;<external>:<internal>]	""
DEFAULT_RIMD_ARTIFACT_URL	where to download the artifacts (kernel + initrd)	https://gitlab.arm.com/api/v4/projects/576/jobs/146089/artifacts
RIMD_ARTIFACT_URL_USER	User to authenticate to get artifacts from URL	""
RIMD_ARTIFACT_URL_PASS	Password to authenticate to get artifacts from URL	""
RIMD_ARTIFACT_URL_TOKEN	Token to authenticate to get artifacts from URL	""
DEFAULT_RIMD_ARTIFACT_FILENAME	Filename to use when storing the downloaded file	artifacts.zip
DEFAULT_RIMD_KERNEL_FILENAME	Filename that contains the kernel to run	final_artifact/Image.gz
DEFAULT_RIMD_IMAGE_FILENAME	Filename that contains the initrd to run	final_artifact/initramfs.linux_arm64.cpio
DEFAULT_RIMD_FILESYSTEM_FILENAME	Filename that contains the read/write filesystem for the VM	final_artifact/something.qcow2

Crismux

Linux and MacOS

clone the repository

git clone https://github.com/smarter-project/hydra

Isolated-vm

TL;DR

The terminal will output VM console messages and the last message should be a login prompt. When running the script directly this will be printed in the current terminal that the script is running. Use VM_USERNAME, VM_PASSWORD to login. Ssh and csi-grpc-proxy interfaces are available through the network.

Two options to exit the VM after it has been started.

• stop the hypervisor by typing "control-a" and "c" and at the hypervisor prompt, type "quit"
• login to the VM using the VM_USERNAME, VM_PASSWORD and execute "`sudo shutdown -h 0"

Run the script start-vm.sh to create the VM using debian cloud image

cd hydra/src/isolated-vm
./start-vm.sh

It will start a VM using local directory image. If run as root (linux) it will also try to share the directories /var/lib/kubelet and /var/log/pods.

Run the script start-vm.sh to create the VM using the kernel/initrd instead of cloud image

cd hydra/src/isolated-vm
RUN_BARE_KERNEL=1 RIMD_ARTIFACT_URL_TOKEN=<access token> ./start-vm.sh

Crismux (needed if using kubernetes)

Run the script install_crismux.sh to enable crismux

cd hydra/src/add-crismux
./install_crismux.sh install