Multus CNI 12 Factor App

Multus CNI 12-Factor

Multus CNI 12 Factor App Kubernetes Multi-Network Pod Interface macvlan ipvlan SR-IOV Storage Management Telco NFV Production

Network Configuration

# === Multus CNI Network Setup ===

# Install Multus CNI
# kubectl apply -f https://raw.githubusercontent.com/k8snetworkplumbingwg/multus-cni/master/deployments/multus-daemonset-thick.yml
#
# Verify
# kubectl get pods -n kube-system | grep multus

# NetworkAttachmentDefinition - Storage Network
# apiVersion: "k8s.cni.cncf.io/v1"
# kind: NetworkAttachmentDefinition
# metadata:
#   name: storage-network
#   namespace: default
# spec:
#   config: '{
#     "cniVersion": "0.3.1",
#     "type": "macvlan",
#     "master": "eth1",
#     "mode": "bridge",
#     "ipam": {
#       "type": "whereabouts",
#       "range": "10.10.0.0/24",
#       "gateway": "10.10.0.1"
#     }
#   }'

# Pod with Multiple Networks
# apiVersion: v1
# kind: Pod
# metadata:
#   name: my-app
#   annotations:
#     k8s.v1.cni.cncf.io/networks: storage-network, mgmt-network
# spec:
#   containers:
#   - name: app
#     image: my-app:latest
#     env:
#     - name: STORAGE_ENDPOINT    # 12-Factor: Config in Env
#       value: "10.10.0.100:9000"
#     - name: MGMT_ENDPOINT
#       value: "10.20.0.100:8080"

from dataclasses import dataclass

@dataclass
class NetworkDef:
    name: str
    cni_type: str
    subnet: str
    purpose: str
    ipam: str

networks = [
    NetworkDef("default-pod-network",
        "calico (Default CNI)",
        "10.244.0.0/16",
        "Service-to-Service ClusterIP NodePort",
        "Calico IPAM (Auto)"),
    NetworkDef("storage-network",
        "macvlan (master: eth1)",
        "10.10.0.0/24",
        "Ceph Storage Replication Backup",
        "whereabouts (Cross-node)"),
    NetworkDef("mgmt-network",
        "macvlan (master: eth2)",
        "10.20.0.0/24",
        "Monitoring Prometheus SSH Admin",
        "whereabouts (Cross-node)"),
    NetworkDef("data-plane",
        "SR-IOV (VF from PF)",
        "10.30.0.0/24",
        "NFV 5G High-throughput Data",
        "host-local (Per-node)"),
]

print("=== Network Definitions ===")
for n in networks:
    print(f"  [{n.name}] CNI: {n.cni_type}")
    print(f"    Subnet: {n.subnet}")
    print(f"    Purpose: {n.purpose}")
    print(f"    IPAM: {n.ipam}")

12-Factor Compliance

# === 12-Factor App with Multus ===

@dataclass
class FactorCompliance:
    factor: str
    principle: str
    multus_implementation: str
    example: str

factors = [
    FactorCompliance("3. Config",
        "Config ใน Environment Variable ไม่ Hardcode",
        "Network Endpoint เก็บใน ConfigMap/Env ไม่ Hardcode IP",
        "STORAGE_ENDPOINT=10.10.0.100:9000 ใน Env"),
    FactorCompliance("4. Backing Services",
        "Backing Service เป็น Attached Resource เปลี่ยนได้",
        "Network เป็น Attached Resource เปลี่ยน NetworkAttachmentDefinition ได้",
        "เปลี่ยน Storage Network จาก macvlan เป็น SR-IOV โดยไม่แก้ App"),
    FactorCompliance("6. Stateless Processes",
        "App เป็น Stateless ไม่เก็บ State ใน Process",
        "Network State อยู่ที่ CNI/IPAM ไม่ใช่ App",
        "Pod ถูก Reschedule ได้ IPAM จัดการ IP ใหม่"),
    FactorCompliance("8. Concurrency",
        "Scale ด้วย Process ไม่ใช่ Thread",
        "Scale Pod ได้ Multus จัดการ Network Interface อัตโนมัติ",
        "kubectl scale --replicas=10 ทุก Pod ได้ Network ครบ"),
    FactorCompliance("9. Disposability",
        "เริ่ม/หยุดเร็ว Graceful Shutdown",
        "Pod Start: CNI Attach Network Interface เร็ว Pod Stop: CNI Release IP",
        "Network Attach/Detach < 1 วินาที"),
    FactorCompliance("10. Dev/Prod Parity",
        "Environment เหมือนกัน",
        "ใช้ NetworkAttachmentDefinition เหมือนกันทุก Env",
        "Dev Staging Production ใช้ YAML เดียวกัน เปลี่ยน Subnet"),
]

print("=== 12-Factor Compliance ===")
for f in factors:
    print(f"\n  [{f.factor}] {f.principle}")
    print(f"    Multus: {f.multus_implementation}")
    print(f"    Example: {f.example}")

Production Monitoring

# === Production Monitoring & Troubleshooting ===

# Troubleshooting Commands
# kubectl exec my-pod -- ip addr              # ดู Interface ทั้งหมด
# kubectl exec my-pod -- ip route             # ดู Routing Table
# kubectl exec my-pod -- ping 10.10.0.100     # ทดสอบ Connectivity
# kubectl describe net-attach-def storage-net # ดู Network Config
# kubectl get net-attach-def -A               # ดู Network ทั้งหมด
# journalctl -u kubelet | grep multus         # ดู Multus Log

@dataclass
class MonitorItem:
    metric: str
    check_command: str
    target: str
    alert: str

monitoring = [
    MonitorItem("Pod Network Interfaces",
        "kubectl exec pod -- ip addr | grep net",
        "ทุก Pod มี Interface ครบตาม Annotation",
        "Missing Interface → P1 Check Multus CNI Log"),
    MonitorItem("IP Address Pool Usage",
        "kubectl get ippools (whereabouts)",
        "< 80% ของ Subnet ที่จัด",
        "> 90% → P2 Expand Subnet หรือ Cleanup"),
    MonitorItem("Network Connectivity",
        "kubectl exec pod -- ping ",
        "RTT < 1ms (Same Node) < 5ms (Cross-node)",
        "Timeout → P1 Check Host Interface CNI Config"),
    MonitorItem("Bandwidth per Network",
        "iperf3 between Pods on each network",
        "Storage > 10Gbps | Mgmt > 1Gbps",
        "< 50% expected → P2 Check MTU Congestion"),
    MonitorItem("Multus DaemonSet Health",
        "kubectl get ds -n kube-system multus",
        "Running on all nodes READY = DESIRED",
        "Not Ready → P1 Node ไม่มี Multi-network"),
]

print("=== Production Monitoring ===")
for m in monitoring:
    print(f"  [{m.metric}]")
    print(f"    Check: {m.check_command}")
    print(f"    Target: {m.target}")
    print(f"    Alert: {m.alert}")

เคล็ดลับ

• whereabouts: ใช้ whereabouts IPAM สำหรับ Multi-node IP Management
• Config: ไม่ Hardcode IP ใช้ ConfigMap/Env ตาม 12-Factor
• SR-IOV: ใช้ SR-IOV สำหรับ Performance-critical Network (NFV)
• Subnet: วางแผน Subnet ไม่ให้ชนกัน ใหญ่พอสำหรับ Scale
• Network Policy: ใช้ Network Policy แยก Traffic ตาม Security Zone

Multus CNI คืออะไร

Meta CNI Plugin Kubernetes Multi-Network Pod Interface macvlan ipvlan SR-IOV bridge NetworkAttachmentDefinition Storage Management NFV

สรุป

Multus CNI 12 Factor App Kubernetes Multi-Network macvlan SR-IOV whereabouts ConfigMap Env Stateless Scale Monitoring Production