api: report worker runtimes per sandbox class (WorkerSandboxClass, WorkerSandboxRuntime, ActorSandboxRuntime) #3008

message WorkerStatus {
  // ... fields 1..4 unchanged ...

  // [Removed] SandboxRuntime default_runtime = 5;
  // [Removed] repeated SandboxRuntime restorable_runtimes = 6;

  // The sandbox classes this Worker runs and the runtimes it runs them
  // under, as reported by the Worker at registration; empty until then, and
  // nothing is placed on the Worker until then. The first registration fixes
  // the set of classes; a later report naming other classes is refused. One
  // entry per class the pool declares: one today.
  //
  // +k8s:optional
  // +k8s:maxItems=1 # keep in sync with WorkerPoolSpec.sandboxClasses
  // +k8s:listType=map
  // +k8s:listMapKey=sandbox_class
  repeated WorkerSandboxClass sandbox_classes = 5;
}

// WorkerSandboxClass is one sandbox class a Worker runs, with the runtimes it
// runs it under. A Worker has one entry per WorkerPool sandboxClasses entry,
// so exactly one today.
message WorkerSandboxClass {
  // e.g. "gvisor", "microvm", as on WorkerPool.spec.sandboxClasses[].name.
  //
  // +k8s:required
  // +k8s:maxLength=63
  // +k8s:customValidation # gvisor or microvm
  string sandbox_class = 1;

  // Runtime that new and cold-booted actors of this class start under.
  // Snapshots matching its version can also warm-boot on this worker.
  //
  // +k8s:required
  WorkerSandboxRuntime default_runtime = 2;

  // Additional runtimes of this class (excluding default_runtime) that this
  // worker can restore snapshots from right now.
  //
  // +k8s:optional
  // +k8s:maxItems=32
  // +k8s:listType=atomic
  repeated WorkerSandboxRuntime restorable_runtimes = 3;
}

// One runtime installed on the worker for that class.
message WorkerSandboxRuntime {
  // Primary compatibility version stamped onto an actor's snapshot when a
  // checkpoint is taken on this runtime. Snapshots matching `version`
  // can warm-boot on this runtime.
  //
  // +k8s:required
  VersionedSandboxCompat version = 1;

  // TODO: Add an informational SandboxConfig version name (e.g. "gvisor-2")
  // once workers report one.
  //
  // [Post-GA] Additional compatibility versions (excluding `version`) that can
  // warm-boot directly onto this runtime. When the actor suspends again, its
  // new snapshot is stamped with the primary `version`.
  // repeated VersionedSandboxCompat compatible_versions = 3;
}

// Concrete runtime and compatibility identity recorded on an actor's
// assignment or snapshot.
message ActorSandboxRuntime {
  // e.g. "gvisor", "microvm"
  //
  // +k8s:required
  // +k8s:maxLength=63
  // +k8s:customValidation # gvisor or microvm
  string sandbox_class = 1;

  // Compatibility version stamped onto an actor's assignment or snapshot.
  //
  // +k8s:required
  VersionedSandboxCompat version = 2;
}

message RegisterWorkerRequest {
  ObjectRef worker = 1;
  WorkerResources capacity = 2;

  // [Removed] SandboxRuntime default_runtime = 3;
  // [Removed] repeated SandboxRuntime restorable_runtimes = 4;

  // +k8s:required
  // +k8s:minItems=1
  // +k8s:maxItems=1 # keep in sync with WorkerPoolSpec.sandboxClasses
  // +k8s:listType=map
  // +k8s:listMapKey=sandbox_class
  repeated WorkerSandboxClass sandbox_classes = 3;
}