> 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/container-restart-check.md).

# Container Restart Check

Container restart check validates the restart count of a container.

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

* **Kubernetes**

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

Container Restart Check probe helps you:

* Verify containers don't restart excessively during chaos experiments
* Monitor container stability during resource stress
* Validate application resilience to failures
* Ensure pods maintain healthy restart counts

***

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

This probe validates that container restart counts remain within acceptable thresholds during chaos experiments. It supports filtering by pod names, labels, or resource kinds (Deployment, StatefulSet, DaemonSet, etc.).

### 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 target namespace and pods
* Sufficient RBAC permissions to query pod status

***

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

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

```
healthchecks -name validate-container-restart
```

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

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

The probe passes when the command output contains `[Pass]`, indicating container restart counts are within the acceptable threshold.

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

| Variable               | Description                                                                           | Required | Default    |
| ---------------------- | ------------------------------------------------------------------------------------- | -------- | ---------- |
| `TARGET_LABELS`        | Comma-separated list of target labels to filter pods (e.g., `app=nginx,env=prod`).    | No       | -          |
| `TARGET_NAMES`         | Comma-separated list of target pod names.                                             | No       | -          |
| `TARGET_NAMESPACE`     | Namespace of the target pods.                                                         | No       | -          |
| `TARGET_KIND`          | Kind of the target resource (e.g., `deployment`, `statefulset`, `daemonset`).         | No       | deployment |
| `TARGET_CONTAINER`     | Name of the container to check restart count.                                         | No       | -          |
| `CONTAINER_RESTART`    | Maximum allowed restart count. Restart count should be equal or less than this value. | No       | 1          |
| `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          |

***

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

```yaml
probe:
  - name: "container-restart-validation"
    type: "cmdProbe"
    mode: "Continuous"
    cmdProbe/inputs:
      command: "healthchecks -name validate-container-restart"
      comparator:
        type: "string"
        criteria: "contains"
        value: "[Pass]"
      env:
        - name: TARGET_LABELS
          value: "app=nginx,tier=frontend"
        - name: TARGET_NAMESPACE
          value: "production"
        - name: TARGET_CONTAINER
          value: "nginx"
        - name: CONTAINER_RESTART
          value: "3"
    runProperties:
      timeout: 180s
      interval: 1s
      attempt: 1
      stopOnFailure: false
```

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

```yaml
probe:
  - name: "specific-pod-restart-check"
    type: "cmdProbe"
    mode: "Edge"
    cmdProbe/inputs:
      command: "healthchecks -name validate-container-restart"
      comparator:
        type: "string"
        criteria: "contains"
        value: "[Pass]"
      env:
        - name: TARGET_NAMES
          value: "my-app-pod-1,my-app-pod-2"
        - name: TARGET_NAMESPACE
          value: "default"
        - name: CONTAINER_RESTART
          value: "5"
        - name: STATUS_CHECK_TIMEOUT
          value: "120"
    runProperties:
      timeout: 150s
      interval: 2s
      attempt: 3
```