---
title: COS node image not used
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Infrastructure as Code (IaC)
  Security > IaC Security Rules > COS node image not used
---

# COS node image not used

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com

{% alert level="danger" %}
This product is not supported for your selected [Datadog site](https://docs.datadoghq.com/getting_started/site.md). ().
{% /alert %}

{% /callout %}

## Metadata{% #metadata %}

**Id:** `be41f891-96b1-4b9d-b74f-b922a918c778`

**Cloud Provider:** GCP

**Platform:** Ansible

**Severity:** Low

**Category:** Insecure Configurations

#### Learn More{% #learn-more %}

- [Provider Reference](https://docs.ansible.com/ansible/latest/collections/google/cloud/gcp_container_node_pool_module.html#parameter-config/image_type)

### Description{% #description %}

GKE node pools should use Container-Optimized OS (COS) images. COS is a Google-managed, hardened OS with automatic security updates and tighter integration with GKE, reducing exposure to unpatched vulnerabilities and kernel-level attack surface.

In Ansible, check tasks using the `google.cloud.gcp_container_node_pool` or `gcp_container_node_pool` modules and ensure the `config.image_type` property is defined and starts with `COS` (case-insensitive). Tasks missing `config.image_type` or with values that do not start with `COS` are flagged.

Secure configuration example:

```yaml
- name: Create GKE node pool with COS image
  google.cloud.gcp_container_node_pool:
    name: my-node-pool
    initial_node_count: 3
    config:
      machine_type: e2-medium
      image_type: COS_CONTAINERD
```

## Compliant Code Examples{% #compliant-code-examples %}

```yaml
- name: create a node pool
  google.cloud.gcp_container_node_pool:
    name: my-pool
    initial_node_count: 4
    cluster: '{{ cluster }}'
    location: us-central1-a
    project: test_project
    auth_kind: serviceaccount
    service_account_file: /tmp/auth.pem
    state: present
    config:
      image_type: COS
```

```yaml
- name: create a node pool
  google.cloud.gcp_container_node_pool:
    name: my-pool
    initial_node_count: 4
    cluster: "{{ cluster }}"
    location: us-central1-a
    project: test_project
    auth_kind: serviceaccount
    service_account_file: /tmp/auth.pem
    state: present
    config:
      image_type: COS_CONTAINERD
```

## Non-Compliant Code Examples{% #non-compliant-code-examples %}

```yaml
---
- name: create a node pool
  google.cloud.gcp_container_node_pool:
    name: my-pool
    initial_node_count: 4
    cluster: "{{ cluster }}"
    location: us-central1-a
    project: test_project
    auth_kind: serviceaccount
    service_account_file: "/tmp/auth.pem"
    state: present
    config:
      image_type: WINDOWS_LTSC
```