2024-07-24

Installing And Configuring Kubevirt On Microk8S

install kubevirt

do not install it on microk8s

install windows on kubevirt:

https://charlottemach.com/2020/11/03/windows-kubevirt-k3s.html

VirtualMachine is like Deployment while VirtualMachineInstance is like Pod

export kubeconfig file path to ~/.bashrc

1 2	export KUBECONFIG=<kubeconfig_filepath>

download and modify the manifests

# prefer ustc and azure mirrors of quay.io
export VERSION=$(curl -s https://api.github.com/repos/kubevirt/kubevirt/releases | grep tag_name | grep -v -- '-rc' | head -1 | awk -F': ' '{print $2}' | sed 's/,//' | xargs)
echo $VERSION
curl -OLk https://github.com/kubevirt/kubevirt/releases/download/${VERSION}/kubevirt-operator.yaml
curl -OLk https://github.com/kubevirt/kubevirt/releases/download/${VERSION}/kubevirt-cr.yaml
export VERSION=$(curl -s https://api.github.com/repos/kubevirt/containerized-data-importer/releases | grep tag_name | grep -v -- '-rc' | head -1 | awk -F': ' '{print $2}' | sed 's/,//' | xargs)
curl -LkO https://ghproxy.net/github.com/kubevirt/containerized-data-importer/releases/download/$VERSION/cdi-operator.yaml
curl -LkO https://ghproxy.net/github.com/kubevirt/containerized-data-importer/releases/download/$VERSION/cdi-cr.yaml

check if it works

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kubectl get pods -n kubevirt
kubectl get vmi

install virtctl

# get the download address from: https://github.com/kubevirt/kubevirt/releases/
curl -LkO <download_address>
sudo mv <downloaded_binary> /usr/bin/virtctl
sudo chmod +x /usr/bin/virtctl

create vm (already with tun device inside)

# init_vm.yaml
apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
name: <vm_name>
spec:
runStrategy: Always
template:
spec:
terminationGracePeriodSeconds: 30
dnsConfig:
nameservers:
- 8.8.8.8
domain:
resources:
requests:
memory: 1024M
devices:
disks:
- name: containerdisk
disk:
bus: virtio
- name: emptydisk
disk:
bus: virtio
- disk:
bus: virtio
name: cloudinitdisk
volumes:
- name: containerdisk
containerDisk:
image: kubevirt/fedora-cloud-container-disk-demo:latest
- name: emptydisk
emptyDisk:
capacity: "2Gi"
- name: cloudinitdisk
cloudInitNoCloud:
userData: |-
#cloud-config
password: fedora
chpasswd: { expire: False }

apply it to run the vm

kubectl apply -f init_vm.yaml
kubectl get vm
kubectl get vmi

to interact with the vm

virtctl console <vm_name>
# ssh config is stored at: ~/.ssh/kube_known_hosts
virtctl ssh <user>@<vm_name>
# run this under gui, with `vncviewer` in path
# install with `apt install tigervnc-viewer`
virtctl vnc <vm_name>

2024-07-21

K8S Load Docker Image

first of all, you can build and upload docker image to registry.

docker login
docker build -t <username>/<imagename>:<tag> -f <dockerfile> <resource_path>
docker push <username>/<imagename>:<tag>

you can upload to docker.io or microk8s provided local registry.

https://microk8s.io/docs/registry-built-in

# for microk8s the registry address is localhost:32000
docker tag <imagename> <registry_addr>/<imagename>
docker push <registry_addr>/<imagename>

you can also build image with minikube:

1 2	minikube image build -t <imagename> -f <dockerfile_path> <resource_path>

load image exported with docker save <image>:<tag>

# ref: https://minikube.sigs.k8s.io/docs/commands/image/
# remember to set a tag to the image imported
# or set the imagePullPolicy to Never
# ref: https://iximiuz.com/en/posts/kubernetes-kind-load-docker-image/
minikube image load <image_filepath>/<docker_image_name>
microk8s images import <image_filepath>
microk8s ctr image import <image_filepath>
k3s ctr image import <image_filepath>

https://blog.scottlowe.org/2020/01/25/manually-loading-container-images-with-containerd/

https://docs.k3s.io/installation/registry-mirror#pushing-images

you can also configure k8s to use docker as container runtime instead.

https://github.com/canonical/microk8s/issues/287

https://docs.k3s.io/advanced#using-docker-as-the-container-runtime