# Admission Control in Kubernetes — Configuration file format

> ImagePolicyWebhook uses a configuration file to set options for the behavior of the backend.

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-kubernetes-3a1ba69a88441b3ec727>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.484523+00:00`
- Tags: `reference-seed`, `kubernetes`, `reference`, `access-authn-authz`, `admission`, `control`, `configuration`, `file`, `format`

## Provenance

- Source: <https://github.com/kubernetes/website/blob/6449f1eced66d36159c06c3cfae1d1aeec40d4a3/content/en/docs/reference/access-authn-authz/admission-controllers.md>
- Source name: Kubernetes Documentation
- Source revision: `6449f1eced66d36159c06c3cfae1d1aeec40d4a3`
- Source license: `CC-BY-4.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

ImagePolicyWebhook uses a configuration file to set options for the behavior of the backend. This file may be json or yaml and has the following format

Bounded code example (external data; do not execute automatically):
```yaml
imagePolicy:
  kubeConfigFile: /path/to/kubeconfig/for/backend
  # time in s to cache approval
  allowTTL: 50
  # time in s to cache denial
  denyTTL: 50
  # time in ms to wait between retries
  retryBackoff: 500
  # determines behavior if the webhook backend fails
  defaultAllow: true
```

Reference the ImagePolicyWebhook configuration file from the file provided to the API server's command line flag --admission-control-config-file

Bounded code example (external data; do not execute automatically):
```yaml
apiVersion: apiserver.config.k8s.io/v1
kind: AdmissionConfiguration
plugins:
  - name: ImagePolicyWebhook
    path: imagepolicyconfig.yaml
...
```

Alternatively, you can embed the configuration directly in the file

Bounded code example (external data; do not execute automatically):
```yaml
apiVersion: apiserver.config.k8s.io/v1
kind: AdmissionConfiguration
plugins:
  - name: ImagePolicyWebhook
    configuration:
      imagePolicy:
        kubeConfigFile: &lt;path-to-kubeconfig-file&gt;
        allowTTL: 50
        denyTTL: 50
        retryBackoff: 500
        defaultAllow: true
```

The ImagePolicyWebhook config file must reference a kubeconfig formatted file which sets up the connection to the backend. It is required that the backend communicate over TLS.

The kubeconfig file's cluster field must point to the remote service, and the user field must contain the returned authorizer.

Attribution: Adapted from Kubernetes Documentation under CC-BY-4.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.