migration-pipeline

Migration Pipeline

Analyzed from commit: 412c71822 on 2026-05-04

Source: pkg/controller/plan/migration.go, pkg/controller/plan/kubevirt.go, pkg/controller/plan/migrator/base/, pkg/controller/plan/migrator/ocp/

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Migration.Run() — Top-Level Loop

The plan controller creates a Migration struct and calls Run() on each reconcile.

Run()
  ├── init()           Build adapter (Client, Builder, Ensurer), KubeVirt helper,
  │                    Scheduler, and Migrator based on source provider type
  ├── begin()          Mark migration started, ensure target namespace,
  │                    build VM status list and pipelines, call migrator.Begin()
  ├── resolveCanceledRefs()
  ├── for each runningVMs()  →  execute(vm)      // Resume already-running VMs
  ├── loop: scheduler.Next() →  execute(vm)      // Schedule new VMs
  └── end()            Check all VMs completed → set Succeeded/Failed/Canceled

Polling: Run() returns PollReQ = 3s until all VMs complete, then NoReQ = 0.

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Migrator Factory

migrator.New(context) in pkg/controller/plan/migrator/doc.go:

Provider Type	Migrator	Notes
openshift	ocp.LiveMigrator	Only for Plan.Spec.Type == MigrationLive
openshift	base.BaseMigrator	For non-live OCP-to-OCP
ec2	ec2migrator	AWS EC2 custom migrator
All others	base.BaseMigrator	vSphere, oVirt, OpenStack, OVA, HyperV

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Migrator Interface

Defined in pkg/controller/plan/migrator/base/doc.go:

type Migrator interface {
    Init() error
    Begin() error
    Complete(*plan.VMStatus)
    Status(plan.VM) *plan.VMStatus
    Reset(*plan.VMStatus, []*plan.Step)
    Itinerary(plan.VM) *libitr.Itinerary
    Pipeline(plan.VM) ([]*plan.Step, error)
    Step(*plan.VMStatus) string
    ExecutePhase(*plan.VMStatus) (bool, error)   // true = handled, false = delegate to migration.go
    Logger() logging.LevelLogger
}