# =============================================================================
# Pre-pull DaemonSet - Alternativa para Cold Start
# =============================================================================
# Garante que imagens críticas estejam em cache em TODOS os nodes.
# Quando KEDA/Cluster Autoscaler criar pods, imagens já estarão disponíveis.
# =============================================================================
#
# COMO USAR:
# 1. Edite a lista de initContainers com suas imagens
# 2. kubectl apply -f prepull-daemonset.yaml
# 3. Aguarde todos os pods ficarem Ready
# 4. Imagens estarão em cache em todos os nodes
#
# QUANDO USAR:
# - Databases (PostgreSQL, MongoDB) que precisam de 100% dos arquivos
# - Apps que precarregam (n8n, Laravel Octane)
# - Qualquer imagem onde eStargz NÃO ajuda
#
# =============================================================================

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: image-prepuller
  namespace: kube-system
  labels:
    app: image-prepuller
    purpose: cold-start-optimization
spec:
  selector:
    matchLabels:
      app: image-prepuller
  template:
    metadata:
      labels:
        app: image-prepuller
    spec:
      # Tolera todos os taints para rodar em TODOS os nodes
      tolerations:
        - operator: Exists

      # InitContainers baixam as imagens e terminam
      initContainers:
        # ---------------------------------------------------------------------
        # PostgreSQL (Container Factory)
        # ---------------------------------------------------------------------
        - name: prepull-postgresql
          image: registry.kube.quest/factory/postgresql:17
          command: ["echo", "PostgreSQL image cached"]
          imagePullPolicy: Always
          resources:
            requests:
              cpu: 1m
              memory: 1Mi
            limits:
              cpu: 10m
              memory: 10Mi

        # ---------------------------------------------------------------------
        # n8n
        # ---------------------------------------------------------------------
        - name: prepull-n8n
          image: docker.n8n.io/n8nio/n8n:latest
          command: ["echo", "n8n image cached"]
          imagePullPolicy: Always
          resources:
            requests:
              cpu: 1m
              memory: 1Mi
            limits:
              cpu: 10m
              memory: 10Mi

        # ---------------------------------------------------------------------
        # PostgreSQL Oficial (para clientes)
        # ---------------------------------------------------------------------
        - name: prepull-postgres-alpine
          image: postgres:17-alpine
          command: ["echo", "PostgreSQL Alpine image cached"]
          imagePullPolicy: Always
          resources:
            requests:
              cpu: 1m
              memory: 1Mi
            limits:
              cpu: 10m
              memory: 10Mi

        # ---------------------------------------------------------------------
        # Redis
        # ---------------------------------------------------------------------
        - name: prepull-redis
          image: redis:7-alpine
          command: ["echo", "Redis image cached"]
          imagePullPolicy: Always
          resources:
            requests:
              cpu: 1m
              memory: 1Mi
            limits:
              cpu: 10m
              memory: 10Mi

      # Container principal apenas mantém o DaemonSet vivo
      containers:
        - name: pause
          image: gcr.io/google_containers/pause:3.9
          resources:
            requests:
              cpu: 1m
              memory: 1Mi
            limits:
              cpu: 10m
              memory: 10Mi

      # Secrets para registries privados
      imagePullSecrets:
        - name: gitlab-registry

---
# =============================================================================
# Secret para Registry Privado (template)
# =============================================================================
# Crie este secret em kube-system se usar registry privado:
#
# kubectl create secret docker-registry gitlab-registry \
#   --namespace=kube-system \
#   --docker-server=registry.kube.quest \
#   --docker-username=<usuario> \
#   --docker-password=<token>
# =============================================================================