Projekte

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
# Local Storage Provisioner Service

There is a service that can discover partitions mounted and linked into a particular directory in the `kubelet` container or block devices linked there and present automatically them as `Persistent Volumes`: [Local Static Provisioner](https://github.com/kubernetes-sigs/sig-storage-local-static-provisioner).
As there are services that can make good use of such volumes and have another means of storage redundancy build in, I set this up similar to the way described in [Getting Started](https://github.com/kubernetes-sigs/sig-storage-local-static-provisioner#getting-started).
As this provisioner can not change the size of the volumes it will select the next larger volume for any claim. For example a 20 GB claim will select a 29.4 GiB volume, a 30 GB claim a 30.2 GiB volume etc.

For flatcar-linux we can follow the advice on the sig-storage-local-static-provisioner website: Mount formatted block storage on `/mnt/local-disks/<UUID>`. The UUID will be used to make sure mixing block devices will fail and not expose data to the wrong host.

1. Create a block device for an acdh-clusterX node on the VM host.  
   Note that the size of the block device should be a little larger than the desired even number if GiB (example: for a 20 GiB volume create a 21 GiB disk) as there is a difference in how disk size is calculated
1. Format the volume on the respective flatcar node. Use ext4 or xfs depending on the needs of the service (for example elasticsearch/opensearch recommeds ext4)  
   `sudo mkfs.ext4 /dev/sdd`
1. reserved blocks for root are not very useful in kubernetes so set them to 0  
   `sudo tune2fs -r 0 /dev/disk/by-uuid/<UUID>`
1. Get the UUID. It is part of the output of mkfs.ext4. It is also for example available using using  
   `ls -l /dev/disk/by-uuid/*`
1. Create a UUID directory in /mnt/local-disks/
1. Create a mount unit to mount the filesystem. The filename needs to match the mount point and is encoded.

```bash
sudo cp /etc/systemd/system/var-lib-rancher.mount "/etc/systemd/system/$(systemd-escape --path /mnt/local-disks/<UUID>).mount"
sudo vi /etc/systemd/system/"$(systemd-escape --path /mnt/local-disks/<UUID>).mount"
# change directory name and device name
# [Unit]
# Description=Mount local storage at /mnt/local-disks/<UUID>
# Before=local-fs.target
# [Mount]
# What=/dev/disk/by-uuid/<UUID>
# Where=/mnt/local-disks/<UUID>
# Type=ext4 or xfs
# [Install]
# WantedBy=local-fs.target
sudo systemctl daemon-reload
sudo systemctl enable "$(systemd-escape --path /mnt/local-disks/<UUID>).mount"
sudo systemctl start "$(systemd-escape --path /mnt/local-disks/<UUID>).mount"
```
Add the `sig-storage-local-static-provisioner`
```yaml
apiVersion: catalog.cattle.io/v1
kind: ClusterRepo
metadata:
  name: sig-storage-local-static-provisioner
spec:
  url: https://kubernetes-sigs.github.io/sig-storage-local-static-provisioner/
```
`values.yaml` (also for rancher app)
```yaml
additionalVolumeMounts: []
additionalVolumes: []
affinity: {}
classes:
  - blockCleanerCommand:
      - /scripts/shred.sh
      - '2'
    fsType: ext4
    hostDir: /mnt/local-disks
    name: local-disks
    namePattern: '*'
    volumeMode: Filesystem
enableWindows: false
fullnameOverride: ''
image: registry.k8s.io/sig-storage/local-volume-provisioner:v2.6.0
initContainers: []
mountDevVolume: true
nameOverride: ''
nodeSelector: {}
nodeSelectorWindows: {}
podAnnotations: {}
podLabels: {}
privileged: true
rbac:
  create: true
resources: {}
serviceAccount:
  create: true
  name: ''
serviceMonitor:
  additionalLabels: {}
  enabled: false
  interval: 10s
  namespace: null
  relabelings: []
setPVOwnerRef: false
tolerations: []
useJobForCleaning: false
useNodeNameOnly: false
```
Now the DeamonSet created with this chart waits for a storage class. Import that using the following K8s definition:
```yaml
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: local-disks
provisioner: kubernetes.io/no-provisioner
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer
```