KubeVirt VM Outage Scenario - Kraken
Detailed implementation of the KubeVirt VM Outage Scenario in Kraken
KubeVirt VM Outage Scenario in Kraken
The kubevirt_vm_outage scenario in Kraken enables users to simulate VM-level disruptions by deleting a Virtual Machine Instance (VMI) to test resilience and recovery capabilities.
Implementation
This scenario is implemented in Kraken’s core repository, with the following key functionality:
- Finding and validating the target VMI
- Deleting the VMI using the KubeVirt API
- Monitoring the recovery process
- Implementing fallback recovery if needed
Usage
You can use this scenario in your Kraken configuration file as follows:
scenarios:
- name: "kubevirt vm outage"
scenario: kubevirt_vm_outage
parameters:
vm_name: <my-application-vm>
namespace: <vm-workloads>
duration: 60
Detailed Parameters
| Parameter | Description | Required | Default | Example Values |
|---|---|---|---|---|
| vm_name | The name of the VMI to delete | Yes | N/A | “database-vm”, “web-server-vm” |
| namespace | The namespace where the VMI is located | No | “default” | “openshift-cnv”, “vm-workloads” |
| duration | How long to wait (in seconds) before attempting recovery | No | 60 | 30, 120, 300 |
Execution Flow
When executed, the scenario follows this process:
- Initialization: Validates KubeVirt is installed and configures the KubeVirt client
- VMI Validation: Checks if the target VMI exists and is in Running state
- State Preservation: Saves the initial state of the VMI
- Chaos Injection: Deletes the VMI using the KubeVirt API
- Wait Period: Waits for the specified duration
- Recovery Monitoring: Checks if the VMI is automatically restored
- Manual Recovery: If automatic recovery doesn’t occur, manually recreates the VMI
- Validation: Confirms the VMI is running correctly
Integration with KubeVirt API
The scenario utilizes the KubeVirt Python client to interact with the KubeVirt API. Key API operations include:
- Reading VMI objects:
kubevirt_api.read_namespaced_virtual_machine_instance() - Deleting VMI objects:
kubevirt_api.delete_namespaced_virtual_machine_instance() - Creating VMI objects:
kubevirt_api.create_namespaced_virtual_machine_instance()
Advanced Use Cases
Testing High Availability VM Configurations
This scenario is particularly useful for testing high availability configurations, such as:
- Clustered applications running across multiple VMs
- VMs with automatic restart policies
- Applications with cross-VM resilience mechanisms
Combining with Other Scenarios
For more comprehensive testing, you can combine this scenario with other Kraken scenarios:
scenarios:
- name: "node outage with vm recovery test"
scenario: node_stop_start_scenario
parameters:
# Node scenario parameters
- name: "vm outage during node recovery"
scenario: kubevirt_vm_outage
parameters:
vm_name: <critical-vm>
namespace: <production>
duration: 120
