508 Kubernetes Security 83c817d3

Kubernetes Security

RBAC (Role-Based Access Control)

Role (namespace-scoped)

apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  namespace: default
  name: pod-reader
rules:
- apiGroups: [""]
  resources: ["pods", "pods/log"]
  verbs: ["get", "list", "watch"]

RoleBinding

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: read-pods
  namespace: default
subjects:
- kind: ServiceAccount
  name: my-app-sa
  namespace: default
roleRef:
  kind: Role
  name: pod-reader
  apiGroup: rbac.authorization.k8s.io

Verify Permissions

kubectl auth can-i get pods --as=system:serviceaccount:default:my-sa
kubectl get roles,rolebindings -n default

Pod Security (Restricted)

spec:
  securityContext:
    runAsNonRoot: true
    runAsUser: 1000
    seccompProfile:
      type: RuntimeDefault
  containers:
  - name: app
    securityContext:
      allowPrivilegeEscalation: false
      readOnlyRootFilesystem: true
      capabilities:
        drop: ["ALL"]

Enable on namespace:

kubectl label namespace default \
  pod-security.kubernetes.io/enforce=restricted

Network Policies

Default Deny

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: default-deny-all
spec:
  podSelector: {}
  policyTypes: [Ingress, Egress]

Allow Specific

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-frontend-to-backend
spec:
  podSelector:
    matchLabels: { app: backend }
  ingress:
  - from:
    - podSelector:
        matchLabels: { app: frontend }
    ports:
    - { protocol: TCP, port: 8080 }

See kubernetes-security-advanced.md for secrets, ClusterRoles, and checklist.