> For the complete documentation index, see [llms.txt](https://developer.harness.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.harness.io/resilience-testing/chaos-engineering/use-chaos-engineering/probes/probe-templates/kubernetes/node-status-check.md).

# Node Status Check

Node status check validates the current state of Kubernetes nodes.

## Infrastructure type <a href="#infrastructure-type" id="infrastructure-type"></a>

* **Kubernetes**

## Use cases <a href="#use-cases" id="use-cases"></a>

Node Status Check probe helps you:

* Verify nodes remain healthy during chaos experiments
* Validate node recovery after failures
* Monitor cluster health during node-level chaos
* Ensure node availability during infrastructure disruptions

***

## Overview <a href="#overview" id="overview"></a>

This probe validates that Kubernetes nodes are in a healthy state during chaos experiments. It supports filtering by node names or labels, making it suitable for checking specific nodes or groups of nodes in your cluster.

### Probe type <a href="#probe-type" id="probe-type"></a>

**Command Probe**

### Prerequisites <a href="#prerequisites" id="prerequisites"></a>

* Kubernetes cluster with chaos infrastructure installed
* Access to cluster nodes
* Sufficient RBAC permissions to query node status

***

## Probe properties <a href="#probe-properties" id="probe-properties"></a>

### Command <a href="#command" id="command"></a>

```
healthchecks -name node-level
```

### Comparator <a href="#comparator" id="comparator"></a>

| Type   | Criteria | Value   |
| ------ | -------- | ------- |
| string | contains | \[Pass] |

The probe passes when the command output contains `[Pass]`, indicating all specified nodes are in a healthy state.

### Environment variables <a href="#environment-variables" id="environment-variables"></a>

| Variable               | Description                                                                                                                                                  | Required | Default |
| ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | -------- | ------- |
| `TARGET_NODE`          | Comma-separated list of nodes to be checked. One of `TARGET_NODE`, `TARGET_NODES`, or `NODE_LABEL` must be specified.                                        | No\*     | -       |
| `TARGET_NODES`         | Comma-separated list of nodes to be checked. One of `TARGET_NODE`, `TARGET_NODES`, or `NODE_LABEL` must be specified.                                        | No\*     | -       |
| `NODE_LABEL`           | Node label to filter nodes to be checked (e.g., `node-role.kubernetes.io/worker=`). One of `TARGET_NODE`, `TARGET_NODES`, or `NODE_LABEL` must be specified. | No\*     | -       |
| `STATUS_CHECK_TIMEOUT` | Maximum time in seconds to wait for status check.                                                                                                            | No       | 180     |
| `STATUS_CHECK_DELAY`   | Delay in seconds between status checks.                                                                                                                      | No       | 2       |

**Note:** At least one of `TARGET_NODE`, `TARGET_NODES`, or `NODE_LABEL` must be provided.

***

## Run properties <a href="#run-properties" id="run-properties"></a>

| Property          | Description                                                              | Type    | Default |
| ----------------- | ------------------------------------------------------------------------ | ------- | ------- |
| `timeout`         | Maximum time to wait for the probe to complete (e.g., `30s`, `1m`, `5m`) | String  | 180s    |
| `interval`        | Time between probe executions (e.g., `1s`, `5s`, `10s`)                  | String  | 1s      |
| `attempt`         | Number of retry attempts before marking the probe as failed              | Integer | 1       |
| `pollingInterval` | Time between retry attempts (e.g., `1s`, `5s`, `10s`)                    | String  | -       |
| `initialDelay`    | Initial delay before starting the probe (e.g., `0s`, `10s`, `30s`)       | String  | -       |
| `stopOnFailure`   | Stop the experiment if the probe fails                                   | Boolean | false   |
| `verbosity`       | Log verbosity level (`info`, `debug`, `trace`)                           | String  | -       |

***

## Probe definition <a href="#probe-definition" id="probe-definition"></a>

You can define this probe in your chaos experiment as follows:

### Using node names <a href="#using-node-names" id="using-node-names"></a>

```yaml
probe:
  - name: "node-health-check"
    type: "cmdProbe"
    mode: "Continuous"
    cmdProbe/inputs:
      command: "healthchecks -name node-level"
      comparator:
        type: "string"
        criteria: "contains"
        value: "[Pass]"
      env:
        - name: TARGET_NODES
          value: "node-1,node-2,node-3"
        - name: STATUS_CHECK_TIMEOUT
          value: "180"
        - name: STATUS_CHECK_DELAY
          value: "2"
    runProperties:
      timeout: 180s
      interval: 1s
      attempt: 1
      stopOnFailure: false
```

### Using node labels <a href="#using-node-labels" id="using-node-labels"></a>

```yaml
probe:
  - name: "worker-nodes-check"
    type: "cmdProbe"
    mode: "Edge"
    cmdProbe/inputs:
      command: "healthchecks -name node-level"
      comparator:
        type: "string"
        criteria: "contains"
        value: "[Pass]"
      env:
        - name: NODE_LABEL
          value: "node-role.kubernetes.io/worker="
        - name: STATUS_CHECK_TIMEOUT
          value: "120"
    runProperties:
      timeout: 150s
      interval: 2s
      attempt: 3
      pollingInterval: 5s
```