Scheduling

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
spec:
  nodeName: worker-node-1  # 직접 노드 지정
  containers:
  - name: nginx
    image: nginx

# Binding 객체를 JSON으로 POST 요청
curl -X POST \
  http://localhost:8001/api/v1/namespaces/default/pods/nginx-pod/binding/ \
  -H 'Content-Type: application/json' \
  -d '{
    "apiVersion": "v1",
    "kind": "Binding",
    "metadata": { "name": "nginx-pod" },
    "target": {
      "apiVersion": "v1",
      "kind": "Node",
      "name": "worker-node-1"
    }
  }'

apiVersion: v1
kind: Pod
metadata:
  name: web-app
  labels:
    app: ecommerce
    tier: frontend
    environment: production
    version: v2.1
spec:
  containers:
  - name: nginx
    image: nginx

# 특정 라벨로 필터링
kubectl get pods -l app=ecommerce
kubectl get pods --selector app=ecommerce

# 여러 조건 (AND)
kubectl get pods -l app=ecommerce,tier=frontend

# 라벨 포함 조회
kubectl get pods --show-labels

# IN 조건
kubectl get pods -l 'environment in (production,staging)'

# NOT 조건
kubectl get pods -l environment!=development

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: frontend-rs
  labels:
    app: frontend     # ReplicaSet 자체의 라벨
spec:
  replicas: 3
  selector:
    matchLabels:
      app: frontend   # 관리할 파드 선택 조건
  template:
    metadata:
      labels:
        app: frontend # 생성될 파드의 라벨 (selector와 일치해야 함)
    spec:
      containers:
      - name: nginx
        image: nginx

spec:
  selector:
    matchExpressions:
    - key: app
      operator: In
      values: ["frontend", "backend"]
    - key: tier
      operator: NotIn
      values: ["cache"]
    - key: environment
      operator: Exists

metadata:
  annotations:
    buildVersion: "1.34.2"
    buildDate: "2024-01-15"
    kubernetes.io/created-by: "deployment-controller"
    description: "Main application pod"

# Taint 추가
kubectl taint nodes node1 app=blue:NoSchedule

# Taint 제거 (끝에 '-' 추가)
kubectl taint nodes node1 app=blue:NoSchedule-

# Taint 확인
kubectl describe node node1 | grep Taint

apiVersion: v1
kind: Pod
metadata:
  name: blue-pod
spec:
  tolerations:
  - key: "app"
    operator: "Equal"
    value: "blue"
    effect: "NoSchedule"
  containers:
  - name: nginx
    image: nginx

# Equal: 정확히 일치
tolerations:
- key: "app"
  operator: "Equal"
  value: "blue"
  effect: "NoSchedule"

# Exists: key만 존재하면 됨 (value 불필요)
tolerations:
- key: "app"
  operator: "Exists"
  effect: "NoSchedule"

kubectl describe node master | grep Taint
# Taints: node-role.kubernetes.io/master:NoSchedule

# 노드에 라벨 추가
kubectl label nodes node1 size=large
kubectl label nodes node2 hardware=gpu

apiVersion: v1
kind: Pod
metadata:
  name: data-processing
spec:
  nodeSelector:
    size: large  # size=large 라벨을 가진 노드에만 배치
  containers:
  - name: processor
    image: data-processor:v1.0

spec:
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: size
            operator: In
            values:
            - large
            - medium

# In: 값 목록 중 하나와 일치
- key: size
  operator: In
  values: ["large", "medium"]

# NotIn: 부정 조건
- key: size
  operator: NotIn
  values: ["small"]

# Exists: 키 존재 여부만 확인
- key: gpu
  operator: Exists

# DoesNotExist: 키가 없는 경우
- key: temporary
  operator: DoesNotExist

spec:
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:  # 조건 1: GPU 노드
          - key: hardware
            operator: In
            values: ["gpu"]
        - matchExpressions:  # 조건 2: 고성능 CPU 노드
          - key: cpu
            operator: In
            values: ["high-performance"]
        # 둘 중 하나만 만족하면 됨 (OR)

spec:
  affinity:
    nodeAffinity:
      preferredDuringSchedulingIgnoredDuringExecution:
      - weight: 100  # 높은 우선순위
        preference:
          matchExpressions:
          - key: zone
            operator: In
            values: ["us-east-1a"]
      - weight: 50   # 낮은 우선순위
        preference:
          matchExpressions:
          - key: zone
            operator: In
            values: ["us-east-1b"]

# 1. 노드에 Taint + Label 적용
kubectl taint nodes blue-node color=blue:NoSchedule
kubectl label nodes blue-node color=blue

# 2. 파드에 Toleration + Affinity 모두 적용
apiVersion: v1
kind: Pod
metadata:
  name: blue-pod
spec:
  tolerations:
  - key: color
    value: blue
    effect: NoSchedule
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: color
            operator: In
            values: ["blue"]
  containers:
  - name: app
    image: nginx

apiVersion: v1
kind: Pod
metadata:
  name: web-app
spec:
  containers:
  - name: app
    image: nginx
    resources:
      requests:        # 최소 보장량 (스케줄링 기준)
        cpu: "500m"
        memory: "512Mi"
      limits:          # 최대 사용량
        cpu: "1"
        memory: "1Gi"

apiVersion: v1
kind: LimitRange
metadata:
  name: resource-limits
  namespace: default
spec:
  limits:
  - type: Container
    default:          # 기본 limits
      cpu: "500m"
      memory: "512Mi"
    defaultRequest:   # 기본 requests
      cpu: "100m"
      memory: "128Mi"
    max:              # 최대 허용
      cpu: "2"
      memory: "4Gi"
    min:              # 최소 요구
      cpu: "50m"
      memory: "64Mi"

apiVersion: v1
kind: ResourceQuota
metadata:
  name: compute-quota
  namespace: backend-team
spec:
  hard:
    requests.cpu: "20"
    requests.memory: "40Gi"
    limits.cpu: "50"
    limits.memory: "100Gi"
    pods: "50"

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: monitoring-daemon
spec:
  selector:
    matchLabels:
      app: monitoring-agent
  template:
    metadata:
      labels:
        app: monitoring-agent
    spec:
      containers:
      - name: agent
        image: monitoring-agent:v1.0
        resources:
          requests:
            cpu: "100m"
            memory: "128Mi"

# kubelet 설정에서 manifest 경로 지정
--pod-manifest-path=/etc/kubernetes/manifests

# 또는 config 파일에서 지정
--config=/var/lib/kubelet/config.yaml

# config.yaml
staticPodPath: /etc/kubernetes/manifests

ls /etc/kubernetes/manifests/
# etcd.yaml
# kube-apiserver.yaml
# kube-controller-manager.yaml
# kube-scheduler.yaml

apiVersion: scheduling.k8s.io/v1
kind: PriorityClass
metadata:
  name: high-priority
value: 1000
globalDefault: false
preemptionPolicy: PreemptLowerPriority
description: "High priority for critical apps"

apiVersion: v1
kind: Pod
metadata:
  name: critical-app
spec:
  priorityClassName: high-priority
  containers:
  - name: app
    image: critical-app:v1.0

kubectl get priorityclass
# system-cluster-critical  ~20억 (클러스터 핵심)
# system-node-critical     ~20억 (노드 핵심)

apiVersion: v1
kind: Pod
metadata:
  name: my-custom-scheduler
  namespace: kube-system
spec:
  containers:
  - name: scheduler
    image: k8s.gcr.io/kube-scheduler:v1.28.0
    command:
    - kube-scheduler
    - --config=/etc/kubernetes/my-scheduler-config.yaml

apiVersion: kubescheduler.config.k8s.io/v1
kind: KubeSchedulerConfiguration
profiles:
- schedulerName: my-custom-scheduler
leaderElection:
  leaderElect: false  # 단일 스케줄러일 때

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  schedulerName: my-custom-scheduler  # 커스텀 스케줄러 사용
  containers:
  - name: nginx
    image: nginx

# 스케줄러 파드 확인
kubectl get pods -n kube-system | grep scheduler

# 이벤트에서 어떤 스케줄러가 처리했는지 확인
kubectl get events -o wide | grep Scheduled

apiVersion: kubescheduler.config.k8s.io/v1
kind: KubeSchedulerConfiguration
profiles:
- schedulerName: default-scheduler
  # 기본 설정

- schedulerName: no-scoring-scheduler
  plugins:
    preScore:
      disabled:
      - name: "*"
    score:
      disabled:
      - name: "*"

- schedulerName: custom-scheduler
  plugins:
    filter:
      disabled:
      - name: TaintToleration
    score:
      enabled:
      - name: MyCustomPlugin

# /etc/kubernetes/manifests/kube-apiserver.yaml
spec:
  containers:
  - command:
    - kube-apiserver
    - --enable-admission-plugins=NodeRestriction,NamespaceAutoProvision
    - --disable-admission-plugins=DefaultTolerationSeconds

apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
metadata:
  name: pod-policy
webhooks:
- name: pod-policy.example.com
  clientConfig:
    service:
      namespace: default
      name: webhook-service
      path: /validate
    caBundle: <base64-encoded-ca-cert>
  rules:
  - apiGroups: [""]
    apiVersions: ["v1"]
    operations: ["CREATE"]
    resources: ["pods"]

# 노드 설정
kubectl taint nodes gpu-node hardware=gpu:NoSchedule
kubectl label nodes gpu-node hardware=gpu

# GPU 워크로드 파드
apiVersion: v1
kind: Pod
metadata:
  name: ml-training
spec:
  tolerations:
  - key: hardware
    value: gpu
    effect: NoSchedule
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: hardware
            operator: In
            values: ["gpu"]
  containers:
  - name: tensorflow
    image: tensorflow/tensorflow:latest-gpu
    resources:
      limits:
        nvidia.com/gpu: 1

# 프로덕션 전용 파드
apiVersion: v1
kind: Pod
metadata:
  name: prod-app
spec:
  tolerations:
  - key: environment
    value: production
    effect: NoSchedule
  affinity:
    nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: environment
            operator: In
            values: ["production"]
  containers:
  - name: app
    image: myapp:prod

# 노드별 리소스 사용량
kubectl top nodes

# 파드별 리소스 사용량
kubectl top pods

# 파드 리소스 상세
kubectl describe pod <pod-name>

# 스케줄링 이벤트
kubectl get events --sort-by='.lastTimestamp'