Container
Kubernetes Security

1# Secure Dockerfile
2FROM ubuntu:22.04  # ✅ Supported base image
3RUN apt-get update && apt-get install -y --no-install-recommends \\
4    package1=1.2.3 package2=4.5.6 && \\  # ✅ Package pinning
5    rm -rf /var/lib/apt/lists/*  # ✅ Reduce image size
6COPY --chown=app:app . /app/  # ✅ Proper permissions
7RUN useradd -r app
8USER app  # ✅ Non-root user
9EXPOSE 8080  # ✅ Non-privileged port
10# ✅ Secrets managed via environment
11COPY . /app/
12CMD ["python", "app.py"]
13 

1# Vulnerable Dockerfile
2FROM ubuntu:18.04  # ❌ EOL base image (367 CVEs)
3RUN apt-get update  # ❌ No package pinning
4COPY secrets.json /app/  # ❌ Secrets in image
5RUN useradd app
6USER root  # ❌ Running as root
7EXPOSE 22  # ❌ SSH exposed
8ENV API_KEY=sk-1234567890  # ❌ Secret in env var
9COPY . /app/
10CMD ["python", "app.py"]
11 

1apiVersion: v1
2kind: Pod
3metadata:
4  name: secure-app
5spec:
6  containers:
7  - name: app
8    image: nginx:1.21  # ✅ Updated secure version
9    securityContext:
10      allowPrivilegeEscalation: false  # ✅ No privilege escalation
11      runAsNonRoot: true              # ✅ Non-root user
12      runAsUser: 1000                 # ✅ Specific UID
13      readOnlyRootFilesystem: true    # ✅ Read-only filesystem
14      capabilities:
15        drop: ["ALL"]                 # ✅ Drop all capabilities
16        add: ["NET_BIND_SERVICE"]     # ✅ Only required caps
17    resources:
18      limits:
19        memory: "256Mi"               # ✅ Resource limits
20        cpu: "200m"
21        ephemeral-storage: "1Gi"
22      requests:
23        memory: "128Mi"
24        cpu: "100m"
25    livenessProbe:                    # ✅ Health checks
26      httpGet:
27        path: /health
28        port: 8080
29    readinessProbe:
30      httpGet:
31        path: /ready
32        port: 8080
33 

1apiVersion: v1
2kind: Pod
3metadata:
4  name: vulnerable-app
5spec:
6  containers:
7  - name: app
8    image: nginx:1.14  # ❌ Vulnerable version
9    securityContext:
10      privileged: true  # ❌ Full host access
11      runAsUser: 0     # ❌ Root user
12    volumeMounts:
13    - name: host-root
14      mountPath: /host  # ❌ Host filesystem access
15  volumes:
16  - name: host-root
17    hostPath:
18      path: /          # ❌ Mount host root
19  hostNetwork: true    # ❌ Host network access
20  hostPID: true        # ❌ Host PID namespace
21