Kubernetes Probe

Configure Kubernetes probes to verify resource state during chaos experiments

K8s Probe verifies the desired state of Kubernetes resources by allowing you to define the resource GVR (group-version-resource) with appropriate filters (field selectors or label selectors). The probe supports three operations:

• present: Checks that matching Kubernetes resources exist

• absent: Checks that matching Kubernetes resources do not exist

• delete: Deletes matching Kubernetes resources

When to use

• Verify that pods remain in Running state during a fault (use present with field selector status.phase=Running)

• Confirm that a Kubernetes resource (e.g., PVC, ConfigMap) is cleaned up after a fault (use absent)

• Delete specific resources as part of experiment teardown (use delete)

• Validate that custom resources or operator-managed resources maintain their expected state under failure conditions

Steps to configure

1. Navigate to Project Settings > Chaos Probes and click + New Probe

2. Select Kubernetes Probe and provide a name, and optionally a description and tags

3. Under Variables, define any reusable values you want to reference in probe properties or run properties. For each variable, specify the type (String or Number), name, value (fixed or runtime input), and whether it's required at runtime.

4. Under Probe Properties, configure:

   Field	Description
   Kubernetes Resource Group	The API group of the resource (leave empty for core resources like pods, services)
   Version	The API version (e.g., v1, v1alpha1)
   Resource	Kind of resource (e.g., pods, deployments, persistentvolumeclaims)
   Resource Names (optional)	Comma-separated resource names to target
   Namespace	The namespace to target (e.g., default)
   Field Selector (optional)	Filter by field values (e.g., status.phase=Running)
   Label Selector (optional)	Filter by labels (e.g., app=nginx)
   Operation	The operation type: present, absent, or delete

5. Provide the Run Properties:

   Field	Description
   Timeout	Maximum time for probe execution (e.g., 10s)
   Interval	Time between successive executions (e.g., 2s)
   Attempt	Number of retry attempts (e.g., 1)
   Polling Interval	Time between retries (e.g., 30s)
   Initial Delay	Delay before first execution (e.g., 5s)
   Verbosity	Log detail level
   Stop On Failure (optional)	Stop the experiment if the probe fails

6. Click Create Probe