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Merge pull request #18 from acend/philipona/second-interation-lab6
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Add tolerations and Feedback to lab 6
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@phil-pona
phil-pona authored Sep 28, 2024
2 parents af4c073 + e9d2760 commit 9455c52
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44 changes: 29 additions & 15 deletions content/en/docs/storage/hotplug-disks.md
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Expand Up @@ -11,8 +11,7 @@ In this section we will hot plug a disk to a running virtual machine.

## {{% task %}} Starting a virtual machine

First, create a file `vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros.yaml` and start with the
following virtual machine definition:
First, create a file `vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros.yaml` in the folder `{{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}` and start with the following virtual machine definition:

```yaml
apiVersion: kubevirt.io/v1
Expand Down Expand Up @@ -44,7 +43,12 @@ spec:
networks:
- name: default
pod: {}
volumes:
{{< onlyWhen tolerations >}}tolerations:
- effect: NoSchedule
key: baremetal
operator: Equal
value: "true"
{{< /onlyWhen >}}volumes:
- name: containerdisk
containerDisk:
image: quay.io/kubevirt/cirros-container-disk-demo
Expand All @@ -56,17 +60,17 @@ spec:
Create and start the virtual machine with:
```bash
kubectl create -f vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros.yaml
kubectl apply -f {{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}/vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros.yaml --namespace=$USER
```

Start the VM with:
```bash
virtctl start {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros
virtctl start {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --namespace=$USER
```

Open a console with:
```bash
virtctl console {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros
virtctl console {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --namespace=$USER
```


Expand Down Expand Up @@ -132,7 +136,7 @@ Actually we can see that we have two disks available.

## {{% task %}} Create a DataVolume to be hot plugged

Create a file `dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk.yaml` with the following content:
Create a file `dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk.yaml` in the folder `{{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}` with the following content:
```yaml
apiVersion: cdi.kubevirt.io/v1beta1
kind: DataVolume
Expand All @@ -151,7 +155,7 @@ spec:
Create the data volume with:
```bash
kubectl create -f dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk.yaml
kubectl apply -f {{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}/dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk.yaml --namespace=$USER
```


Expand All @@ -160,14 +164,13 @@ kubectl create -f dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumbe
Hotplug the disk by using `virtctl`:

```bash
virtctl addvolume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --volume-name={{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk
virtctl addvolume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --volume-name={{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk --namespace=$USER
```
```
Successfully submitted add volume request to VM {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros for volume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk
```

After some time the device will be hot plugged to your virtual machine. You may get a first hint where your new disk is
plugged in with `dmesg`:
After some time the device will be hot plugged to your virtual machine. You may get a first hint where your new disk is plugged in by executing `dmesg` in the vm console:

```bash
dmesg
Expand Down Expand Up @@ -262,7 +265,7 @@ sudo touch /mnt/disk/myfile

You can remove a hot plugged disk with:
```bash
virtctl removevolume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --volume-name={{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk
virtctl removevolume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --volume-name={{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk --namespace=$USER
```
```
Successfully submitted remove volume request to VM {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros for volume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk
Expand All @@ -274,11 +277,22 @@ What happens if you remount the disk again? Is the created file `/mnt/disk/myfil
After hot plugging and mounting the volume again the file is still present. There is no need to format the device again.
However, the mounting needs to be done again. You may mount disks with startup scripts like cloud-init.

Beware that the device might have a different name: `sdb`

Mount the disk again with:
```bash
sudo mkdir /mnt/disk
sudo mount /dev/sda /mnt/disk/
sudo mount /dev/sdb /mnt/disk/
```

Check whether the file `/mnt/disk/myfile` still exists.

And don't forget to remove the disk again:

```bash
virtctl removevolume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --volume-name={{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk --namespace=$USER
```

{{% /details %}}


Expand All @@ -288,7 +302,7 @@ With the above steps we have hot plugged a disk into the vm. This mount is not p
or shutdown the disk is not attached. When you want to mount the disk persistently you can use the `--persist` flag.

```bash
virtctl addvolume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --volume-name={{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk --persist
virtctl addvolume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros --volume-name={{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk --persist --namespace=$USER
```
```
Successfully submitted add volume request to VM {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros for volume {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-hotplug-disk
Expand All @@ -297,7 +311,7 @@ Successfully submitted add volume request to VM {{% param "labsubfolderprefix" %
This will add the relevant sections to your `VirtualMachine` manifest. You can show the modified configuration with:

```bash
kubectl get vm {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros -o yaml
kubectl get vm {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cirros -o yaml --namespace=$USER
```
```bash
apiVersion: kubevirt.io/v1
Expand Down
67 changes: 42 additions & 25 deletions content/en/docs/storage/mounting-storage.md
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Expand Up @@ -36,7 +36,7 @@ spec:
claimName: harddisk-pvc
```
The following types are the most important volume type which KubeVirt supports:
The following types are the most important volume types which KubeVirt supports:
* cloudInitNoCloud: Attach a cloud-init data source. Requires a proper setup of cloud-init.
* cloudInitConfigDrive: Attach a cloud-init data source. Similar to cloudInitNoCloud this requires a proper setup of cloud-init. The config-drive can be used for Ignition.
Expand Down Expand Up @@ -111,7 +111,7 @@ to know that a volume mounted as a filesystem does not allow Live Migration.

## PersistentVolumeClaims as block or filesystem devices

It might be a confusing as the name filesystem is overloaded. In this section we are talking about the storage mode of a
It might be a bit confusing as the name filesystem is overloaded. In this section we are talking about the storage mode of a
PersistentVolumeClaim and not the mounting inside our guest. Kubernetes supports the `volumeMode` type `block` and
`filesystem` (default). Whether you can use `block` devices or not depends on your CSI driver supporting block volumes.

Expand Down Expand Up @@ -169,7 +169,7 @@ tool like cloud-init.

### {{% task %}} Prepare and create disks and configmaps

First we create a disk using the default `Filesystem` volumeMode. Create the file `dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-fs-disk.yaml` with the following content:
First we create a disk using the default `Filesystem` volumeMode. Create the file `dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-fs-disk.yaml` in the folder `{{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}` with the following content:
```yaml
apiVersion: cdi.kubevirt.io/v1beta1
kind: DataVolume
Expand All @@ -188,10 +188,10 @@ spec:
```
Create the filesystem backed disk in the kubernetes cluster:
```bash
kubectl create -f dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-fs-disk.yaml --namespace=$USER
kubectl apply -f {{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}/dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-fs-disk.yaml --namespace=$USER
```

Second we create a disk using the `Block` volumeMode. Create the file `dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-block-disk.yaml` with the following content:
Second we create a disk using the `Block` volumeMode. Create the file `dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-block-disk.yaml` in the folder `{{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}` with the following content:
```yaml
apiVersion: cdi.kubevirt.io/v1beta1
kind: DataVolume
Expand All @@ -210,10 +210,10 @@ spec:
```
Create the block storage disk in the kubernetes cluster:
```bash
kubectl create -f dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-block-disk.yaml --namespace=$USER
kubectl apply -f {{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}/dv_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-block-disk.yaml --namespace=$USER
```

Next we create a cloud-init configuration secret. Create a file `cloudinit-userdata.yaml` with the following content:
Next we create a cloud-init configuration secret. Create a file `cloudinit-userdata.yaml` in the folder `{{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}` with the following content:
```yaml
#cloud-config
password: kubevirt
Expand All @@ -222,10 +222,10 @@ timezone: Europe/Zurich
```
Create the secret in the kubernetes cluster:
```bash
kubectl create secret generic {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cloudinit --from-file=userdata=cloudinit-userdata.yaml --namespace=$USER
kubectl create secret generic {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-cloudinit --from-file=userdata={{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}/cloudinit-userdata.yaml --namespace=$USER
```

Last we create a ConfigMap with some values for an application. Create a file `cm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-application.yaml` with the following content:
Last we create a ConfigMap with some values for an application. Create a file `cm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-application.yaml` in the folder `{{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}` with the following content:
```yaml
kind: ConfigMap
apiVersion: v1
Expand All @@ -240,7 +240,7 @@ data:

Now create the ConfigMap in the kubernetes cluster:
```bash
kubectl create -f cm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-application.yaml --namespace=$USER
kubectl apply -f {{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}/cm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-application.yaml --namespace=$USER
```


Expand All @@ -257,7 +257,7 @@ We create a virtual machine mounting the following storage:
* ServiceAccount to /serviceaccounts/default
* ConfigMap to /configmaps/application

The VirtualManifest for this looks like the following snipped. Create a file `vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage.yaml` with the following content:
The VirtualManifest for this looks like the following snipped. Create a file `vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage.yaml` in the folder `{{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}` with the following content:
```yaml
apiVersion: kubevirt.io/v1
kind: VirtualMachine
Expand Down Expand Up @@ -301,6 +301,11 @@ spec:
networks:
- name: default
pod: {}
tolerations:
- effect: NoSchedule
key: baremetal
operator: Equal
value: "true"
volumes:
- name: containerdisk
containerDisk:
Expand Down Expand Up @@ -344,20 +349,20 @@ spec:

Create the virtual machine in the kubernetes cluster:
```bash
kubectl create -f vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage.yaml --namespace=$USER
kubectl apply -f {{% param "labsfoldername" %}}/{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}/vm_{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage.yaml --namespace=$USER
```

Start the virtual machine with:
```bash
virtctl start {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage
virtctl start {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage --namespace=$USER
```

Open a console to the virtual machine:
```bash
virtctl console {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage
virtctl console {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage --namespace=$USER
```

After logging in you can examine the virtual machine. First you may check the block device output with `lsblk`:
After logging in (user: `fedora`, passowrd: `kubevirt`) you can examine the virtual machine. First you may check the block device output with `lsblk`:
```bash
lsblk
```
Expand Down Expand Up @@ -399,10 +404,21 @@ tmpfs 197M 4.0K 197M 1% /run/user/1000
configmap-fs 226G 123G 94G 57% /configmaps/application
```

Explore how the cloud init secret and the config map have been mounted in the VM by using the following commands:
```bash
ls -l /secrets/cloudinit/
cat /secrets/cloudinit/userdata
```
```bash
ls -l /configmaps/application/
cat /configmaps/application/singlevalue
cat /configmaps/application/application.properties
```

Next try to edit the config map within kubernetes. You can open a new terminal in your webshell or leave the console
and head back later. Issue the following command to alter the ConfigMap:
```bash
kubectl patch cm {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-application --type json --patch '[{ "op": "replace", "path": "/data/singlevalue", "value": "kubevirt-training" }]'
kubectl patch cm {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-application --type json --patch '[{ "op": "replace", "path": "/data/singlevalue", "value": "kubevirt-training" }]' --namespace=$USER
```

After some time the change should be seamlessly be propagated to your vm. Head back to the console and check the value
Expand All @@ -420,10 +436,11 @@ kubevirt-training
Another thing to note is how our virtual machine pods is set up. Leave the console and describe the `virt-launcher` pod
responsible for your vm:
```bash
kubectl describe pod virt-launcher-{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage-qfmlk --namespace=$USER
```
kubectl describe pod virt-launcher-{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage-<pod> --namespace=$USER
```
Name: virt-launcher-{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage-qfmlk

```bash
Name: virt-launcher-{{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage-<pod>
[...]
Containers:
[...]
Expand Down Expand Up @@ -477,7 +494,7 @@ Volumes:
Type: EmptyDir (a temporary directory that shares a pod's lifetime)
kube-api-access-mmf6t:
Type: Projected (a volume that contains injected data from multiple sources)
````
```
This is a highly shortened output of the pod description showing the relevant sections. Our virt-launcher pod has multiple
helper containers managing the mounts. Every storage is shown in the volumes block. The ServiceAccount is actually in
Expand All @@ -489,8 +506,8 @@ should be available.
Our two PersistentVolumeClaims - one backed by Filesystem and one beeing a raw block device - are mounted differently.
* **fsdisk**: Is in the Mount block of the `compute` container.
* **blockdisk**: Our block storage disk is not show in the Mount block of the `compute` container. However, we see the `blockdisk` as `/dev/blockdisk` in the Devices section in the `compute` container. This means that our block storage is indeed passed as a device.
* **fsdisk**: Is in the mount block () of the `compute` container.
* **blockdisk**: Our block storage disk is not show in the mount block of the `compute` container. However, we see the `blockdisk` as `/dev/blockdisk` in the devices section in the `compute` container. This means that our block storage is indeed passed as a device.
#### Filesystem Mounts: Virtiofs volumes
Expand All @@ -501,7 +518,7 @@ For each mounted filesystem there is a supporting container `virtiofs-<volume>`.
Let's analyze the `virtiofs-serviceaccount-fs` and `compute` container.

```
```bash
Containers:
compute:
[...]
Expand Down Expand Up @@ -537,6 +554,6 @@ communicate with `virtiofsd` in `virtiofs-serviceaccount-fs`.
## Stop your VM

As we are at the end of this section it is time to stop your running virtual machine with:
```yaml
virtctl stop {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage
```bash
virtctl stop {{% param "labsubfolderprefix" %}}{{% param "labfoldernumber" %}}-storage --namespace=$USER
```
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