[CPCAP-12251] feature: fsmount

[alexarefev]

Description

• The functionality to mount some storage before the k8s installation is needed
• The ZRAM storage for /var/log/pods must be add to configuration, but disabled by default

Solution

• Add new task fsmount into preparation section with the following description:

services:
  fsmount:
  - name: fs1
    size: 1G
    type: ext4
    device: /dev/sdd1
    path: /mnt
    template:
      source: templates/plugins/fsmount-setup.service.j2
      destination: /etc/systemd/system/fsmount-setup.service
    preparation_scripts:
      - resources/scripts/upgrade_kernel.sh
      - resources/scripts/fsprep.sh
	groups: [control-plane, workers]
	nodes: []

name - name of the item just for indication
enabled - defines if the item must be processed
device - the device file
path - the mount point
size - the size of the disk, it's needed for example for tmpfs (optional)
template.source - the path to systemctl unit template that should be rendered by the options above
template.destination - the path where the systemctl unit must be put on the cluster node
preparation_script - the script that must be finished successfully to initiate the filesystem creation (optional); basically it install necessary packages, modules and so no to run systemctl unit successfully; if it finishes with error fsmount task for that item must be skipped
groups - the list of the nodes roles where the task must be applied (optional)
nodes - the list of the nodes where the task must be applied (optional)
groups and nodes must be merged before the run; if both groups and nodes are empty - the task is skipped

• Add template, script for ZRAM storage
• Add check_paas task
• Update documentation

Test Cases

TestCase 1

Check if the installation procedure is working

Test Configuration:

• Hardware: 2CPU/4GB
• OS: Ubuntu 24.04
• Inventory: Allinone

Steps:

1. Run kubemarine install with the following settings in cluster.yaml:

services:
  kubeadm_kubelet:
    containerLogMaxSize: 5Mi
    containerLogMaxFiles: 2
  fsmount:
  - name: zram
    size: 1G
    type: ext4
    device: /dev/zram0
    path: /var/log/pods
    template:
      source: templates/zram-setup.service.j2
      destination: /etc/systemd/system/zram-setup.service
    preparation_scripts:
      - resources/scripts/upgrade_kernel.sh
      - resources/scripts/zram.sh
    groups: [control-plane, worker]

Results:

Before	After
not applicable	/dev/zram0 is mounted to /var/log/pods; containerLogMax options are set in /var/lib/kubelet/config.yaml

TestCase 2

Check if the mount_fs procedure is working

Test Configuration:

• Hardware: 2CPU/4GB
• OS: Ubuntu 24.04
• Inventory: Allinone

Steps:

1. Run kubemarine reconfigure on existing cluster with the following settings in procedure.yaml:

services:
  kubeadm_kubelet:
    containerLogMaxSize: 5Mi
    containerLogMaxFiles: 2

2. Run kubemarine mount_fs on existing cluster with the following settings in procedure.yaml:

fsmount:
  - name: zram
    size: 1G
    type: ext4
    device: /dev/zram0
    path: /var/log/pods
    template:
      source: templates/zram-setup.service.j2
      destination: /etc/systemd/system/zram-setup.service
    preparation_scripts:
      - resources/scripts/upgrade_kernel.sh
      - resources/scripts/zram.sh
    groups: [control-plane, worker]
reboot: true

Results:

Before	After
not applicable	/dev/zram0 is mounted to /var/log/pods; containerLogMax options are set in /var/lib/kubelet/config.yaml

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• There is no breaking changes, or migration patch is provided
• Integration CI passed
• Unit tests. If Yes list of new/changed tests with brief description
• There is no merge conflicts

[disa1217]

@alexarefev , checked.

[disa1217]

@alexarefev , checked the documents.