coreos-kvm

README.md

coreos-kvm

coreos-kvm is a container images which runs a QEMU/KVM CoreOS VM.

Usage

Run the container image as a privileged container. Provide Ignition or Cloud-Config user-data to provision the guest instance.

# config
sudo docker run --name kvm --privileged -e CONFIG_FILE=/userdata/config.yaml -v $PWD/examples/config.yaml:/userdata/config.yaml quay.io/dghubble/coreos-kvm

# ignition
sudo docker run --name kvm --privileged -e IGNITION_CONFIG_FILE=/userdata/ignition.json -v $PWD/examples/ignition.json:/userdata/ignition.json quay.io/dghubble/coreos-kvm

# cloud-config
sudo docker run --name kvm --privileged -e CLOUD_CONFIG_FILE=/userdata/cloud.yaml -v $PWD/examples/cloud.yaml:/userdata/cloud.yaml quay.io/dghubble/coreos-kvm

SSH into the container IP on port 2222.

sudo docker network inspect bridge
ssh -p 2222 core@172.17.0.2

The container runs a local port (2222) forward to the CoreOS VM (22).

Environment Variables

env variable	example
CONFIG_FILE	/userdata/config.yaml
IGNITION_CONFIG_FILE	/userdata/ignition.json
CLOUD_CONFIG_FILE	/userdata/cloud.yaml
VM_NAME	coreos-kvm
VM_MEMORY	4G
VM_DISK_SIZE	12G
HOSTFWD	hostfwd=tcp::2222-:22

Development

To develop the container image, build it locally.

Container Image

Build the container image.

make docker-image

Run

Run the container image as a privileged container. Provide Ignition or Cloud-Config user-data to provision the guest instance.

# config
sudo docker run --name kvm --privileged -e CONFIG_FILE=/userdata/config.yaml -v $PWD/examples/config.yaml:/userdata/config.yaml dghubble/coreos-kvm

# ignition
sudo docker run --name kvm --privileged -e IGNITION_CONFIG_FILE=/userdata/ignition.json -v $PWD/examples/ignition.json:/userdata/ignition.json dghubble/coreos-kvm

# cloud-config
sudo docker run --name kvm --privileged -e CLOUD_CONFIG_FILE=/userdata/cloud.yaml -v $PWD/examples/cloud.yaml:/userdata/cloud.yaml dghubble/coreos-kvm

Remove the container from another terminal.

sudo docker stop kvm
sudo docker rm kvm

build

#!/usr/bin/env bash
set -exu

# dependencies
apt-get update
apt-get install -y \
  curl \
  bzip2 \
  openssh-client \
  qemu-kvm

URL="http://${CL_CHANNEL}.release.core-os.net/amd64-usr/${CL_VERSION}/coreos_production_qemu_image.img.bz2"
echo "Downloading Container Linux $CL_CHANNEL $CL_VERSION $URL"
curl -O $URL
bzip2 -d coreos_production_qemu_image.img.bz2

curl -L https://github.com/coreos/container-linux-config-transpiler/releases/download/v0.3.0/ct-v0.3.0-x86_64-unknown-linux-gnu -o ct
chmod +x ct

apt-get remove -y curl bzip2
apt-get autoremove -y
apt-get clean
rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

Dockerfile

FROM ubuntu:16.10
MAINTAINER Dalton Hubble <dghubble@gmail.com>
ARG CL_CHANNEL
ARG CL_VERSION
COPY scripts /scripts
RUN /scripts/build
EXPOSE 2222
ENTRYPOINT ["/scripts/start"]

start

#!/usr/bin/env bash
set -eox pipefail

VM_NAME="${VM_NAME:-coreos-kvm}"
VM_MEMORY="${VM_MEMORY:-4G}"
VM_DISK_SIZE="${VM_DISK_SIZE:-12G}"
# hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport
HOSTFWD="${HOSTFWD:-hostfwd=tcp::2222-:22}"

if [ -n "${CLOUD_CONFIG_FILE}" ]; then
  echo "Setting cloud config file: ${CLOUD_CONFIG_FILE}"
  mkdir -p "${PWD}/openstack/latest"
  cp "${CLOUD_CONFIG_FILE}" "${PWD}/openstack/latest/user_data"
  cat "${PWD}/openstack/latest/user_data"
  set -- \
      -fsdev local,id=conf,security_model=none,readonly,path="${PWD}" \
      -device virtio-9p-pci,fsdev=conf,mount_tag=config-2 "$@"
fi

if [ -n "${IGNITION_CONFIG_FILE}" ]; then
  echo "Setting ignition config file: ${IGNITION_CONFIG_FILE}"
  cat "${IGNITION_CONFIG_FILE}"
  set -- -fw_cfg name=opt/com.coreos/config,file="${IGNITION_CONFIG_FILE}" "$@"
fi

if [ -n "$CONFIG_FILE" ]; then
  echo "Transpiling config file: ${CONFIG_FILE}"
  cat "${CONFIG_FILE}"
  ./ct -in-file $CONFIG_FILE -out-file ${PWD}/ignition.json
  echo "Setting ignition config file ${PWD}/ignition.json"
  cat "${PWD}/ignition.json"
  set -- -fw_cfg name=opt/com.coreos/config,file="${PWD}/ignition.json" "$@"
fi

qemu-img resize ./coreos_production_qemu_image.img "${VM_DISK_SIZE}"

# https://alpha.release.core-os.net/amd64-usr/current/coreos_production_qemu.sh
qemu-system-x86_64 \
  -name "${VM_NAME}" \
  -enable-kvm \
  -cpu host \
  -m "${VM_MEMORY}" \
  -net nic,model=virtio \
  -net user,"${HOSTFWD}",hostname="${VM_NAME}" \
  -drive if=virtio,file=./coreos_production_qemu_image.img \
  -nographic \
  -machine accel=kvm \
  -smp 2 \
  "$@"