# Example deployment compliant with RESTRICTED Pod Security Standard
# This is the gold standard for secure workloads
apiVersion: apps/v1
kind: Deployment
metadata:
  name: secure-app
  namespace: restricted-apps
  labels:
    app: secure-app
    security.kubernetes.io/compliant: "restricted"
spec:
  replicas: 2
  selector:
    matchLabels:
      app: secure-app
  template:
    metadata:
      labels:
        app: secure-app
    spec:
      # Pod-level security context
      securityContext:
        runAsNonRoot: true
        runAsUser: 65534          # nobody user
        runAsGroup: 65534
        fsGroup: 65534
        seccompProfile:
          type: RuntimeDefault

      # Prevent service account token auto-mount unless needed
      automountServiceAccountToken: false

      containers:
        - name: app
          image: nginx:1.27-alpine
          ports:
            - containerPort: 8080
              protocol: TCP

          # Container-level security context
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsNonRoot: true
            runAsUser: 65534
            capabilities:
              drop:
                - ALL
              # Only add NET_BIND_SERVICE if binding to ports < 1024
              # add:
              #   - NET_BIND_SERVICE

          # Resource limits (required for production)
          resources:
            requests:
              cpu: 100m
              memory: 128Mi
            limits:
              cpu: 500m
              memory: 256Mi

          # Probes for reliability
          livenessProbe:
            httpGet:
              path: /healthz
              port: 8080
            initialDelaySeconds: 10
            periodSeconds: 10

          readinessProbe:
            httpGet:
              path: /ready
              port: 8080
            initialDelaySeconds: 5
            periodSeconds: 5

          # Volume mounts for writable paths (since root is read-only)
          volumeMounts:
            - name: tmp
              mountPath: /tmp
            - name: cache
              mountPath: /var/cache/nginx
            - name: run
              mountPath: /var/run

      volumes:
        # EmptyDir for ephemeral writable storage
        - name: tmp
          emptyDir:
            sizeLimit: 100Mi
        - name: cache
          emptyDir:
            sizeLimit: 100Mi
        - name: run
          emptyDir:
            sizeLimit: 10Mi

      # Topology spread for high availability
      topologySpreadConstraints:
        - maxSkew: 1
          topologyKey: kubernetes.io/hostname
          whenUnsatisfiable: ScheduleAnyway
          labelSelector:
            matchLabels:
              app: secure-app