# Same repository structure works across ALL backends:
KOPIA_REPOSITORY: s3://bucket/backups        # S3
KOPIA_REPOSITORY: gcs://bucket/backups       # Google Cloud  
KOPIA_REPOSITORY: azure://container/backups  # Azure
KOPIA_REPOSITORY: sftp://server/path         # SFTP
# ... exact same backup format and features regardless of backend!

# Kopia automatically handles complex nested paths
KOPIA_REPOSITORY: s3://my-bucket/team-a/prod/databases/postgres
# ↓ Kopia parses this as:
# Bucket: my-bucket
# Prefix: team-a/prod/databases/postgres
# Features: Lifecycle policies, versioning, encryption all work

# Same secret can contain credentials for multiple backends
apiVersion: v1
kind: Secret
stringData:
  # Primary backend
  KOPIA_REPOSITORY: s3://primary-bucket/backups
  AWS_ACCESS_KEY_ID: primary-key
  
  # Fallback backend (Kopia can migrate between backends)
  KOPIA_FALLBACK_REPOSITORY: gcs://fallback-bucket/backups  
  GOOGLE_APPLICATION_CREDENTIALS: |
    {"type": "service_account", ...}

apiVersion: volsync.backube/v1alpha1
kind: ReplicationSource
metadata:
  name: database-backup
spec:
  sourcePVC: my-database
  kopia:
    repository: kopia-config
    # Performance tuning
    compression: zstd              # zstd, gzip, s2, none
    parallelism: 4                 # Parallel upload streams
    
    # Retention policy
    retain:
      hourly: 24                   # Keep 24 hourly backups
      daily: 7                     # Keep 7 daily backups  
      weekly: 4                    # Keep 4 weekly backups
      monthly: 12                  # Keep 12 monthly backups
      yearly: 5                    # Keep 5 yearly backups
    
    # Cache configuration (flexible EmptyDir fallback)
    cacheCapacity: 8Gi             # Cache size
    cacheStorageClassName: fast-ssd # Optional PVC cache
    cacheAccessModes: [ReadWriteOnce]
    
    # Multi-tenancy
    username: team-frontend        # Custom username
    hostname: prod-cluster-db      # Custom hostname
    
    # Application consistency  
    actions:
      beforeSnapshot: "pg_start_backup('volsync')"
      afterSnapshot: "pg_stop_backup()"
    
    # Path preservation
    sourcePathOverride: /var/lib/postgresql/data
    
    # Maintenance
    maintenanceIntervalDays: 7     # Run maintenance weekly

# Strategy 1: No cache config → EmptyDir fallback (good for testing)
spec:
  kopia: {}
# Result: EmptyDir with 8Gi limit, reasonable performance

# Strategy 2: Size-only config → EmptyDir with limit (good for constrained resources)  
spec:
  kopia:
    cacheCapacity: 4Gi
# Result: EmptyDir with 4Gi limit, predictable resource usage

# Strategy 3: Full config → Dedicated PVC (best for production)
spec:
  kopia:
    cacheCapacity: 20Gi
    cacheStorageClassName: fast-nvme
# Result: Persistent PVC, maximum performance

kopia:
  # Option 1: Structured JSON config (validated)
  policyConfig:
    repositoryConfig: |
      {
        "splitters": {"default": "DYNAMIC-4M-BUZHASH"},
        "compression": {"compressor": "zstd", "level": 3},
        "encryption": {"algorithm": "CHACHA20-POLY1305"},
        "caching": {"maxCacheSizeBytes": 1073741824}
      }
  
  # Option 2: File-based policies from ConfigMap/Secret  
  policyConfig:
    configMapName: kopia-policies
    globalPolicyFilename: global-policy.json
    repositoryConfigFilename: repo.config

apiVersion: volsync.backube/v1alpha1
kind: ReplicationSource
metadata:
  name: postgres-backup
spec:
  sourcePVC: postgres-data
  trigger:
    schedule: "0 2 * * *"  # Daily at 2 AM
  kopia:
    repository: postgres-backup-config
    retain:
      daily: 30
      weekly: 12
    actions:
      beforeSnapshot: "pg_start_backup('volsync')"
      afterSnapshot: "pg_stop_backup()"

apiVersion: volsync.backube/v1alpha1
kind: ReplicationSource
metadata:
  name: app-backup-prod
spec:
  sourcePVC: app-data
  trigger:
    schedule: "0 */6 * * *"  # Every 6 hours
  kopia:
    repository: s3-backup-config
    compression: zstd
    parallelism: 8
    cacheCapacity: 32Gi
    cacheStorageClassName: fast-nvme
    username: production-app
    hostname: prod-cluster-east
    retain:
      hourly: 48
      daily: 30
      weekly: 26
      monthly: 24
      yearly: 7
    policyConfig:
      repositoryConfig: |
        {
          "compression": {"compressor": "zstd", "level": 9},
          "encryption": {"algorithm": "CHACHA20-POLY1305"},
          "splitters": {"default": "DYNAMIC-4M-BUZHASH"}
        }

apiVersion: volsync.backube/v1alpha1
kind: ReplicationDestination
metadata:
  name: restore-from-backup
spec:
  kopia:
    repository: s3-backup-config
    restoreAsOf: "2024-01-15T10:30:00Z"  # Point-in-time restore
    shallow: 1                           # Only restore recent data
  volumeSnapshotClassName: csi-snapclass
  capacity: 100Gi