---
title: Deployment has no podAntiAffinity
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > Code Security > Infrastructure as Code (IaC)
  Security > IaC Security Rules > Deployment has no podAntiAffinity
---

# Deployment has no podAntiAffinity

{% callout %}
# Important note for users on the following Datadog sites: app.ddog-gov.com, us2.ddog-gov.com

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

{% /callout %}

## Metadata{% #metadata %}

**Id:** `terraform-kubernetes-deployment-has-no-pod-anti-affinity` 

**Provider:** Kubernetes

**Platform:** Terraform

**Severity:** Low

**Category:** Resource Management

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

- [Provider Reference](https://registry.terraform.io/providers/hashicorp/kubernetes/latest/docs/resources/deployment#affinity)

### Description{% #description %}

Checks whether Deployment resources with `replicas > 2` include a `podAntiAffinity` policy to prevent multiple pods from being scheduled on the same node. The rule verifies that `.spec.template.spec.affinity.pod_anti_affinity` is present and that either `required_during_scheduling_ignored_during_execution` or `preferred_during_scheduling_ignored_during_execution` is configured. It also ensures the `topology_key` is set to `kubernetes.io/hostname` and that the `label_selector.match_labels` entries match labels on the Pod template.

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

```terraform
resource "kubernetes_deployment" "example433" {
  metadata {
    name = "terraform-example"
    labels = {
      k8s-app = "prometheus"
    }
  }

  spec {
    replicas = 3

    selector {
      match_labels = {
        k8s-app = "prometheus"
      }
    }

    template {
      metadata {
        labels = {
          k8s-app = "prometheus"
        }
      }

      spec {
        affinity {
          pod_anti_affinity {
            preferred_during_scheduling_ignored_during_execution {
              weight = 100

              pod_affinity_term {
                label_selector {
                  match_labels {
                    k8s-app = "prometheus"
                  }
                }

                topology_key = "kubernetes.io/hostname"
              }
            }
         }
        }

        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }
        }
      }
    }
  }
}
```

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

```terraform
resource "kubernetes_deployment" "example" {
  metadata {
    name = "terraform-example"
    labels = {
      k8s-app = "prometheus"
    }
  }

  spec {
    replicas = 3

    selector {
      match_labels = {
        k8s-app = "prometheus"
      }
    }

    template {
      metadata {
        labels = {
          k8s-app = "prometheus"
        }
      }

      spec {
        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }
        }
      }
    }
  }
}
```

```terraform
resource "kubernetes_deployment" "example2" {
  metadata {
    name = "terraform-example"
    labels = {
      k8s-app = "prometheus"
    }
  }

  spec {
    replicas = 3

    selector {
      match_labels = {
        k8s-app = "prometheus"
      }
    }

    template {
      metadata {
        labels = {
          k8s-app = "prometheus"
        }
      }

      spec {
        affinity {
          pod_affinity {
              required_during_scheduling_ignored_during_execution {
                label_selector {
                  match_expressions {
                    key      = "security"
                    operator = "In"
                    values   = ["S1"]
                  }
                }

                topology_key = "failure-domain.beta.kubernetes.io/zone"
              }
          }
        }

        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }
        }
      }
    }
  }
}
```

```terraform
resource "kubernetes_deployment" "example3" {
  metadata {
    name = "terraform-example"
    labels = {
      k8s-app = "prometheus"
    }
  }

  spec {
    replicas = 3

    selector {
      match_labels = {
        k8s-app = "prometheus"
      }
    }

    template {
      metadata {
        labels = {
          k8s-app = "prometheus"
        }
      }

      spec {
        affinity {
          pod_anti_affinity {
            preferred_during_scheduling_ignored_during_execution {
              weight = 100

              pod_affinity_term {
                label_selector {
                  match_expressions {
                    key      = "security"
                    operator = "In"
                    values   = ["S2"]
                  }
                }

                topology_key = "failure-domain.beta.kubernetes.io/zone"
              }
            }
         }
        }

        container {
          image = "nginx:1.7.8"
          name  = "example"

          resources {
            limits = {
              cpu    = "0.5"
              memory = "512Mi"
            }
            requests = {
              cpu    = "250m"
              memory = "50Mi"
            }
          }

          liveness_probe {
            http_get {
              path = "/nginx_status"
              port = 80

              http_header {
                name  = "X-Custom-Header"
                value = "Awesome"
              }
            }

            initial_delay_seconds = 3
            period_seconds        = 3
          }
        }
      }
    }
  }
}
```