Pod or Container Without LimitRange

• Query id: 4a20ebac-1060-4c81-95d1-1f7f620e983b
• Query name: Pod or Container Without LimitRange
• Platform: Kubernetes
• Severity: Low
• Category: Insecure Configurations
• URL: Github

Description

Each namespace should have a LimitRange policy associated to ensure that resource allocations of Pods, Containers and PersistentVolumeClaims do not exceed the defined boundaries
Documentation

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: frontend1
  namespace: myPod
spec:
  containers:
  - name: app
    image: images.my-company.example/app:v4
    securityContext:
      allowPrivilegeEscalation: false
    resources:
      requests:
        memory: "64Mi"
        cpu: "250m"
      limits:
        memory: "128Mi"
        cpu: "500m"

Positive test num. 2 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: frontend2
spec:
  containers:
  - name: app
    image: images.my-company.example/app:v4
    securityContext:
      allowPrivilegeEscalation: false
    resources:
      requests:
        memory: "64Mi"
        cpu: "250m"
      limits:
        memory: "128Mi"
        cpu: "500m"

Positive test num. 3 - yaml file

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd-elasticsearch
  namespace: kube-system
  labels:
    k8s-app: fluentd-logging
spec:
  selector:
    matchLabels:
      name: fluentd-elasticsearch
  template:
    metadata:
      labels:
        name: fluentd-elasticsearch
    spec:
      tolerations:
      - key: node-role.kubernetes.io/master
        operator: Exists
        effect: NoSchedule
      containers:
      - name: fluentd-elasticsearch
        image: quay.io/fluentd_elasticsearch/fluentd:v2.5.2
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 200Mi
        volumeMounts:
        - name: varlog
          mountPath: /var/log
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
      terminationGracePeriodSeconds: 30
      volumes:
      - name: varlog
        hostPath:
          path: /var/log
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers

Positive test num. 4 - yaml file

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: webcontent
  namespace: k8s-test9
  annotations:
    volume.alpha.kubernetes.io/storage-class: default
spec:
  accessModes: [ReadWriteOnce]
  resources:
    requests:
      storage: 5Gi

Code samples without security vulnerabilities

Negative test num. 1 - yaml file

apiVersion: v1
kind: Pod
metadata:
  name: frontend
  namespace: myPod2
spec:
  containers:
  - name: app
    image: images.my-company.example/app:v4
    securityContext:
      allowPrivilegeEscalation: false
    resources:
      requests:
        memory: "64Mi"
        cpu: "250m"
      limits:
        memory: "128Mi"
        cpu: "500m"
---
apiVersion: v1
kind: LimitRange
metadata:
  name: cpu-min-max-demo-lr
  namespace: myPod2
spec:
  limits:
  - max:
      cpu: "800m"
    min:
      cpu: "200m"
    type: Container

Negative test num. 2 - yaml file

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd-elasticsearch
  namespace: kube-system2
  labels:
    k8s-app: fluentd-logging
spec:
  selector:
    matchLabels:
      name: fluentd-elasticsearch
  template:
    metadata:
      labels:
        name: fluentd-elasticsearch
    spec:
      tolerations:
      - key: node-role.kubernetes.io/master
        operator: Exists
        effect: NoSchedule
      containers:
      - name: fluentd-elasticsearch
        image: quay.io/fluentd_elasticsearch/fluentd:v2.5.2
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 200Mi
        volumeMounts:
        - name: varlog
          mountPath: /var/log
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
      terminationGracePeriodSeconds: 30
      volumes:
      - name: varlog
        hostPath:
          path: /var/log
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers
---
apiVersion: v1
kind: LimitRange
metadata:
  name: cpu-min-max-demo-lr
  namespace: kube-system2
spec:
  limits:
  - max:
      cpu: "800m"
    min:
      cpu: "200m"
    type: Container