VolSync Builders

VolSync Builders - ReplicationSource and ReplicationDestination

The volsync package provides strongly-typed constructor functions for VolSync (volsync.backube/v1alpha1) resources. It is the canonical entry point for building ReplicationSource and ReplicationDestination objects in kure.

Overview

VolSync replicates persistent volume data between Kubernetes clusters. Each replication direction (source and destination) selects exactly one mover — the data-transfer backend — from a sum of choices: Restic, Rsync (legacy SSH), RsyncTLS, Rclone, Syncthing (source-only), or an External passthrough.

This package encodes the mover one-of as a sealed-interface sum type: Mover on the parent Config holds exactly one variant. Setting two movers is a compile error; setting none is detected at construction. See docs/ARCHITECTURE.md § One-of Constraints for the rationale.

Supported Resources

Resource	Movers
`ReplicationSource`	Restic · Rsync · RsyncTLS · Rclone · Syncthing · External
`ReplicationDestination`	Restic · Rsync · RsyncTLS · Rclone · External

ReplicationSource

import (
    volsyncv1alpha1 "github.com/backube/volsync/api/v1alpha1"

    "github.com/go-kure/kure/pkg/kubernetes/volsync"
)

schedule := "@hourly"
rs := volsync.ReplicationSource(&volsync.ReplicationSourceConfig{
    Name:      "db-backup",
    Namespace: "data",
    SourcePVC: "postgres-data",
    Trigger:   &volsync.TriggerConfig{Schedule: &schedule},
    Mover: &volsync.SourceResticConfig{
        Repository: "restic-creds",
        ReplicationSourceVolumeOptions: volsyncv1alpha1.ReplicationSourceVolumeOptions{
            CopyMethod: volsync.CopyMethodSnapshot,
        },
        Retain: &volsyncv1alpha1.ResticRetainPolicy{
            Daily:   ptr.Int32(7),
            Weekly:  ptr.Int32(4),
            Monthly: ptr.Int32(12),
        },
    },
})

ReplicationDestination

rd := volsync.ReplicationDestination(&volsync.ReplicationDestinationConfig{
    Name:      "db-restore",
    Namespace: "dr",
    Trigger:   &volsync.TriggerConfig{Manual: "restore-1"},
    Mover: &volsync.DestinationResticConfig{
        Repository: "restic-creds",
        ReplicationDestinationVolumeOptions: volsyncv1alpha1.ReplicationDestinationVolumeOptions{
            CopyMethod:  volsync.CopyMethodSnapshot,
            Capacity:    resource.MustParse("10Gi").DeepCopy(),
            AccessModes: []corev1.PersistentVolumeAccessMode{corev1.ReadWriteOnce},
        },
    },
})

Movers

Mover	Purpose
`Restic`	Encrypted, deduplicated snapshots to a restic repository (S3, B2, etc.).
`Rsync`	Legacy SSH-based rsync. Prefer `RsyncTLS` for new deployments.
`RsyncTLS`	rsync over a TLS pre-shared key.
`Rclone`	Sync to/from any rclone-supported backend (S3, GCS, Azure, etc.).
`Syncthing`	Continuous bidirectional sync over the Syncthing protocol (source resource only).
`External`	Passthrough for custom replication providers — opaque `provider` + `parameters`.

Modifier Functions

// Trigger
volsync.SetReplicationSourceSchedule(rs, "@daily")
volsync.SetReplicationSourceManualTrigger(rs, "go")
volsync.SetReplicationDestinationSchedule(rd, "@weekly")
volsync.SetReplicationDestinationManualTrigger(rd, "go")

// Spec fields
volsync.SetReplicationSourceSourcePVC(rs, "data")
volsync.SetReplicationSourcePaused(rs, true)
volsync.SetReplicationDestinationPaused(rd, true)

// Replace mover (clears any existing mover first)
volsync.SetReplicationSourceMover(rs, &volsync.SourceRcloneConfig{ /* ... */ })
volsync.SetReplicationDestinationMover(rd, &volsync.DestinationResticConfig{ /* ... */ })

// Syncthing peers
volsync.AddSyncthingPeer(syncCfg, "tcp://peer:22000", "PEER-ID", false)

kubernetes-builders — broader resource builder family
stack — domain model that produces Kubernetes resources