substrate/cmd/ateapi/internal/controlapi/actor.go

// Copyright 2026 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package controlapi

import (
	"context"
	"crypto/rand"
	"crypto/x509"
	"crypto/x509/pkix"
	"errors"
	"fmt"
	"log/slog"
	"net/url"
	"slices"
	"time"

	"github.com/agent-substrate/substrate/cmd/ateapi/internal/defaults"
	"github.com/agent-substrate/substrate/cmd/ateapi/internal/store"
	"github.com/agent-substrate/substrate/internal/actoridjwt"
	"github.com/agent-substrate/substrate/internal/ateattr"
	"github.com/agent-substrate/substrate/internal/resources"
	"github.com/agent-substrate/substrate/internal/substratex509"
	"github.com/agent-substrate/substrate/pkg/proto/ateapipb"
	"go.opentelemetry.io/otel/attribute"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/credentials"
	"google.golang.org/grpc/peer"
	"google.golang.org/grpc/status"
	"google.golang.org/protobuf/proto"
	"k8s.io/apimachinery/pkg/api/operation"
	"k8s.io/apimachinery/pkg/api/validate"
	"k8s.io/apimachinery/pkg/util/validation/field"
)

func (s *RPCService) CreateActor(ctx context.Context, req *ateapipb.CreateActorRequest) (created *ateapipb.Actor, err error) {
	// First scrub any fields that users are not allowed to set, then fill the
	// defaults so validation sees the final resource state.
	inActor := req.Actor
	if inActor != nil { // otherwise validation will flag it
		scrubResourceMetadataForCreate(inActor.Metadata)
		inActor.Status = nil
		defaults.Apply(inActor)
	}

	// Validate the request, including the object within it.
	if errs := validateCreateActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}

	start := time.Now()
	// Recorded only after validation, so every operation uniformly measures a
	// validated request; malformed ones stay visible in rpc.server.call.duration.
	defer func() {
		s.instruments.recordLifecycleOp(ctx, ateattr.OperationCreate, start, err,
			ateattr.TemplateNameKey.String(inActor.GetActorTemplate().GetName()),
			ateattr.TemplateAtespaceKey.String(inActor.GetActorTemplate().GetAtespace()),
		)
	}()

	setSpanActorRefAttributes(ctx, resources.ActorRefFromActor(inActor))

	// Handle the creation, including validation of the final stored object.
	stored, err := s.impl.CreateActor(ctx, inActor)
	setSpanActorAttributes(ctx, stored)

	return stored, err
}

func (s *ServiceImpl) CreateActor(ctx context.Context, inActor *ateapipb.Actor) (*ateapipb.Actor, error) {
	// Check that the referenced ActorTemplate exists.
	// FIXME: This is not atomic and it is not a guarantee that the template
	// will still exist later.  Checking it here produces a nice error UX, but
	// we still have to handle the template not existing later, which makes the
	// UX inconsistent, at best.  Is it actually worth checking at all?
	template, err := resolveActorTemplate(ctx, s.store, inActor)
	if err != nil {
		return nil, err
	}

	// Resolve the explicit tag, or freeze the template's current golden default.
	tagRef := inActor.GetSourceTag()
	if tagRef == nil {
		tagRef = template.GetStatus().GetGoldenSnapshotStatus().GetGoldenTag()
	} else {
		for _, volume := range template.GetVolumes() {
			if volume.GetExternalVolumeTemplate() != nil {
				// TODO: Permit cloning after CSI volume snapshots are supported.
				return nil, status.Error(codes.FailedPrecondition, "Tag cloning does not support ActorTemplates with external volumes")
			}
		}
	}
	var sourceTag *ateapipb.Tag
	if tagRef != nil {
		sourceTag, err = s.resolveTagSource(ctx, inActor.GetMetadata().GetAtespace(), tagRef, template)
		if err != nil {
			return nil, err
		}
		if inActor.GetSourceTag() == nil {
			if err := validateGoldenSnapshotScope(sourceTag.GetStatus().GetSnapshot()); err != nil {
				return nil, err
			}
		}
	}

	atespace := inActor.GetMetadata().GetAtespace()
	name := inActor.GetMetadata().GetName()

	// Volume creation is completed asynchronously after the actor is recorded.
	initVols, err := initialActorVolumes(ctx, s.storageClassLister, template)
	if err != nil {
		return nil, err
	}

	// Verify that the result is properly valid before storing it.
	outActor := proto.CloneOf(inActor)
	outActor.Status = &ateapipb.ActorStatus{
		State:        ateapipb.ActorState_ACTOR_STATE_SUSPENDED,
		ActorVolumes: initVols,
	}
	if sourceTag != nil {
		// The Actor starts out borrowing the tag's external snapshot rather than
		// copying it. The snapshot URI is under the tag's prefix, not the Actor's, which
		// is what keeps the Actor from collecting those objects. Its first
		// suspend writes a snapshot under its own prefix and takes over from
		// there.
		outActor.Status.ExternalSnapshot = proto.CloneOf(sourceTag.GetStatus().GetSnapshot())
		// The Actor is born with guest state, so stamp the template that state
		// was built on now rather than at the first resume. Left empty, a
		// repoint before that first resume reads as "no guest state" instead of
		// "replaced template", and the resume restores the old template's
		// memory and rootfs in full instead of the volume data alone.
		outActor.Status.CurrentActorTemplateUid = sourceTag.GetStatus().GetActorTemplateUid()
	}
	if errs := validateActorUpdate(ctx, field.NewPath("actor"), outActor, inActor, true); len(errs) > 0 {
		return nil, toGRPCInternalError(errs)
	}

	// Save the data in the storage layer.
	stored, err := s.store.CreateActor(ctx, outActor)
	if err != nil {
		if errors.Is(err, store.ErrAlreadyExists) {
			return nil, status.Errorf(codes.AlreadyExists, "Actor %s already exists", name)
		}
		if errors.Is(err, store.ErrFailedPrecondition) {
			return nil, status.Errorf(codes.FailedPrecondition, "Atespace %s not found", atespace)
		}
		return nil, fmt.Errorf("while recording actor: %w", err)
	}

	// Without this an actor that is created and never resumed has no record at
	// all, at any retention.
	logActorStateChanged(ctx, stored, ateattr.OperationCreate)

	return stored, nil
}

// resolveTagSource resolves a CreateActor request's source tag
// and checks that the tag is usable for creating an Actor in actorAtespace
// from template.
func (s *ServiceImpl) resolveTagSource(ctx context.Context, actorAtespace string, tagRef *ateapipb.ObjectRef, template *ateapipb.ActorTemplate) (*ateapipb.Tag, error) {
	tag, err := s.store.GetTag(ctx, resources.TagRefFromObjectRef(tagRef))
	if errors.Is(err, store.ErrNotFound) {
		return nil, status.Error(codes.NotFound, "Tag not found")
	}
	if err != nil {
		return nil, fmt.Errorf("while getting tag: %w", err)
	}
	switch tag.GetScope() {
	case ateapipb.TagScope_TAG_SCOPE_ATESPACE:
		if tag.GetMetadata().GetAtespace() != actorAtespace {
			return nil, status.Error(codes.FailedPrecondition, "Tag is not published outside its Atespace")
		}
	case ateapipb.TagScope_TAG_SCOPE_PUBLISHED:
	default:
		return nil, status.Error(codes.FailedPrecondition, "source Tag has an invalid scope")
	}
	// A tag might have an empty Snapshot URI if the tag creation failed or is ongoing.
	if tag.GetStatus().GetSnapshot().GetSnapshotUri() == "" {
		return nil, status.Error(codes.FailedPrecondition, "source Tag is still being created or failed creation")
	}
	// TODO: Permit compatible DATA snapshots when runtimes can extract portable data.
	if tag.GetStatus().GetActorTemplateUid() != template.GetMetadata().GetUid() {
		return nil, status.Errorf(codes.FailedPrecondition, "source Tag must be taken from an actor with ActorTemplate uid %q", tag.GetStatus().GetActorTemplateUid())
	}
	return tag, nil
}

func validateCreateActorRequest(ctx context.Context, req *ateapipb.CreateActorRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_CreateActorRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) GetActor(ctx context.Context, req *ateapipb.GetActorRequest) (*ateapipb.Actor, error) {
	if errs := validateGetActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}
	actorRef := resources.ActorRefFromObjectRef(req.GetActor())
	actor, err := s.impl.GetActor(ctx, actorRef)
	if errors.Is(err, store.ErrNotFound) {
		return nil, status.Errorf(codes.NotFound, "Actor %s not found", actorRef)
	} else if err != nil {
		return nil, fmt.Errorf("while getting actor from DB: %w", err)
	}
	return actor, nil
}

func (s *ServiceImpl) GetActor(ctx context.Context, actorRef resources.ActorRef) (*ateapipb.Actor, error) {
	return s.store.GetActor(ctx, actorRef)
}

func validateGetActorRequest(ctx context.Context, req *ateapipb.GetActorRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_GetActorRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) ListActors(ctx context.Context, req *ateapipb.ListActorsRequest) (*ateapipb.ListActorsResponse, error) {
	if errs := validateListActorsRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}

	page, err := s.impl.ListActors(ctx, req.GetAtespace(), store.ListOptions{PageSize: effectivePageSize(req.GetPageSize()), PageToken: req.GetPageToken()})
	if err != nil {
		return nil, mapListError(fmt.Errorf("while listing actors in db: %w", err))
	}
	return &ateapipb.ListActorsResponse{
		Actors:        page.Items,
		NextPageToken: page.NextPageToken,
	}, nil
}

func (s *ServiceImpl) ListActors(ctx context.Context, atespace string, opts store.ListOptions) (store.ListResponse[*ateapipb.Actor], error) {
	return s.store.ListActors(ctx, atespace, opts)
}

func validateListActorsRequest(ctx context.Context, req *ateapipb.ListActorsRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_ListActorsRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) UpdateActor(ctx context.Context, req *ateapipb.UpdateActorRequest) (*ateapipb.Actor, error) {
	// First scrub any fields that users are not allowed to set.
	inActor := req.Actor
	if inActor != nil { // otherwise validation will flag it
		scrubResourceMetadataForUpdate(inActor.Metadata)
		inActor.Status = nil
	}

	// Validate the request.
	if errs := validateUpdateActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}

	actorRef := resources.ActorRefFromActor(inActor)
	setSpanActorRefAttributes(ctx, actorRef)

	storedActor, err := s.impl.UpdateActor(ctx, actorRef, store.PreconditionFrom(inActor), func(toUpdate *ateapipb.Actor) error {
		// Status and Metadata are server-owned fields.
		status, metadata := toUpdate.GetStatus(), toUpdate.GetMetadata()
		// Whole-object replace: clear first, so a field the client left unset is
		// cleared rather than kept from the stored actor.
		// Merge cannot smuggle in unknown fields because validation already rejected them.
		proto.Reset(toUpdate)
		proto.Merge(toUpdate, inActor)
		// Restore status and metadata from the server.
		toUpdate.Status = status
		toUpdate.Metadata = metadata
		defaults.Apply(toUpdate)
		return nil
	})
	if err != nil {
		return nil, err
	}

	setSpanActorAttributes(ctx, storedActor)

	return storedActor, err
}

func (s *ServiceImpl) UpdateActor(ctx context.Context, actorRef resources.ActorRef, precondition store.Precondition, mutate func(*ateapipb.Actor) error) (*ateapipb.Actor, error) {
	storedActor, err := s.store.UpdateActor(ctx, actorRef, precondition, func(toUpdate *ateapipb.Actor) error {
		// Apply the mutation function to the stored value.
		oldVal := proto.CloneOf(toUpdate)
		if err := mutate(toUpdate); err != nil {
			return err
		}
		newVal := toUpdate

		// Validate the user's input before doing any further work.
		if errs := validateActorUpdate(ctx, field.NewPath("actor"), newVal, oldVal, false); len(errs) > 0 {
			return toGRPCStatusError(errs)
		}

		// Do any further work on the resource.

		// Update actor template is only allowed while the actor is suspended.
		// The repointed ref must also resolve, mirroring CreateActor's
		// check (same non-atomicity caveat; resume re-resolves and fails
		// cleanly), and the replacement's sandbox config, volumes, and
		// volume mounts must match the old template's.
		if !proto.Equal(oldVal.GetActorTemplate(), newVal.GetActorTemplate()) {
			if state := oldVal.GetStatus().GetState(); state != ateapipb.ActorState_ACTOR_STATE_SUSPENDED {
				return status.Errorf(codes.FailedPrecondition,
					"actor must be %s to change its actor template (got: %s)", ateapipb.ActorState_ACTOR_STATE_SUSPENDED, state)
			}
			newTemplate, err := resolveActorTemplate(ctx, s.store, newVal)
			if err != nil {
				return err
			}
			oldTemplate, err := resolveActorTemplate(ctx, s.store, oldVal)
			switch {
			case err == nil:
				// Snapshots are not portable across sandbox runtime
				// families, so the replacement template must name the same
				// SandboxConfig.
				if !proto.Equal(oldTemplate.GetSandboxConfig(), newTemplate.GetSandboxConfig()) {
					oldSC, newSC := oldTemplate.GetSandboxConfig(), newTemplate.GetSandboxConfig()
					return status.Errorf(codes.FailedPrecondition,
						"the current actor template names SandboxConfig %q (class %s) but the new one names %q (class %s); the sandbox config must be identical to repoint an actor",
						oldSC.GetConfigName(), oldSC.GetSandboxClass(), newSC.GetConfigName(), newSC.GetSandboxClass())
				}
				if err := validateTemplateVolumesUnchanged(oldTemplate, newTemplate); err != nil {
					return err
				}
			case errors.Is(err, errActorTemplateNotFound):
				// The old template is gone, so there is nothing left to
				// compare the sandbox config or volume layout against.
			default:
				return err
			}
		}

		// Validate the final value before storing it.
		if errs := validateActorUpdate(ctx, field.NewPath("actor"), newVal, oldVal, true); len(errs) > 0 {
			return toGRPCInternalError(errs)
		}

		return nil
	})
	if err != nil {
		if errors.Is(err, store.ErrVersionConflict) {
			return nil, status.Error(codes.Aborted, "concurrent update conflict, please retry")
		}
		if errors.Is(err, store.ErrUIDConflict) {
			return nil, status.Error(codes.Aborted, "concurrent update conflict, please retry")
		}
		if errors.Is(err, store.ErrNotFound) {
			return nil, status.Errorf(codes.NotFound, "actor %s not found", actorRef)
		}
		if errors.Is(err, store.ErrPreconditionRequired) {
			return nil, status.Errorf(codes.InvalidArgument, "while updating actor %s: %v", actorRef, err)
		}
		return nil, fmt.Errorf("while updating actor: %w", err)
	}
	return storedActor, nil
}

// validateTemplateVolumesUnchanged rejects a template repoint that changes
// the template's volumes or any container's volume mounts: an actor's
// snapshot data is laid out per the volumes and mount paths it was captured
// with, so a different layout would restore it to the wrong places. The
// volumes list must be identical, and containers present in both templates
// must keep identical mounts, order included; containers added or removed by
// the new template are unconstrained.
func validateTemplateVolumesUnchanged(oldTemplate, newTemplate *ateapipb.ActorTemplate) error {
	if !slices.EqualFunc(oldTemplate.GetVolumes(), newTemplate.GetVolumes(), func(a, b *ateapipb.Volume) bool {
		return proto.Equal(a, b)
	}) {
		return status.Error(codes.FailedPrecondition,
			"volumes differ between the current and the new actor template; volumes must be identical to repoint an actor")
	}

	newContainers := make(map[string]*ateapipb.Container, len(newTemplate.GetContainers()))
	for _, c := range newTemplate.GetContainers() {
		newContainers[c.GetName()] = c
	}
	for _, oldC := range oldTemplate.GetContainers() {
		newC, ok := newContainers[oldC.GetName()]
		if !ok {
			continue
		}
		if !slices.EqualFunc(oldC.GetVolumeMounts(), newC.GetVolumeMounts(), func(a, b *ateapipb.VolumeMount) bool {
			return proto.Equal(a, b)
		}) {
			return status.Errorf(codes.FailedPrecondition,
				"volume mounts of container %q differ between the current and the new actor template; volume mounts must be identical to repoint an actor", oldC.GetName())
		}
	}
	return nil
}

func validateUpdateActorRequest(ctx context.Context, req *ateapipb.UpdateActorRequest) field.ErrorList {
	// Call the generated validation.
	// We model this as a create rather than an update because updates assume
	// the existence of a "current" value, which we do not have yet.  This is
	// validating the request itself. The result will be validated later, after
	// we have a current value to compare against.
	op := operation.Operation{Type: operation.Create}
	return Validate_UpdateActorRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) DeleteActor(ctx context.Context, req *ateapipb.DeleteActorRequest) (deleted *ateapipb.Actor, err error) {
	if errs := validateDeleteActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}
	start := time.Now()
	// Template dims only once the record resolved: the request names only the
	// actor, so failures before the load carry none. No pool pair: delete only
	// runs from SUSPENDED or CRASHED, which already released the worker.
	defer func() {
		var attrs []attribute.KeyValue
		if deleted != nil {
			attrs = append(attrs,
				ateattr.TemplateNameKey.String(deleted.GetActorTemplate().GetName()),
				ateattr.TemplateAtespaceKey.String(deleted.GetActorTemplate().GetAtespace()),
			)
		}
		s.instruments.recordLifecycleOp(ctx, ateattr.OperationDelete, start, err, attrs...)
	}()
	actorRef := resources.ActorRefFromObjectRef(req.GetActor())
	setSpanActorRefAttributes(ctx, actorRef)

	deleted, err = s.actorWorkflow.DeleteActor(ctx, actorRef, req.GetAnyState(), toDeletePreconditions(req.GetOptions()))
	if err != nil {
		return nil, err
	}

	return deleted, nil
}

func (s *ServiceImpl) DeleteActor(ctx context.Context, actorRef resources.ActorRef, precondition store.DeletePreconditions) (*ateapipb.Actor, error) {
	return s.store.DeleteActor(ctx, actorRef, precondition)
}

func validateDeleteActorRequest(ctx context.Context, req *ateapipb.DeleteActorRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_DeleteActorRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) PauseActor(ctx context.Context, req *ateapipb.PauseActorRequest) (*ateapipb.PauseActorResponse, error) {
	if errs := validatePauseActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}
	actorRef := resources.ActorRefFromObjectRef(req.GetActor())
	setSpanActorRefAttributes(ctx, actorRef)

	actor, err := s.actorWorkflow.PauseActor(ctx, actorRef)
	if err != nil {
		if errors.Is(err, store.ErrVersionConflict) {
			return nil, status.Error(codes.Aborted, "concurrent update conflict, please retry")
		}
		if errors.Is(err, store.ErrNotFound) {
			return nil, status.Errorf(codes.NotFound, "Actor %s not found", actorRef)
		}
		return nil, err
	}

	setSpanActorAttributes(ctx, actor)
	return &ateapipb.PauseActorResponse{Actor: actor}, nil
}

func validatePauseActorRequest(ctx context.Context, req *ateapipb.PauseActorRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_PauseActorRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) ResumeActor(ctx context.Context, req *ateapipb.ResumeActorRequest) (*ateapipb.ResumeActorResponse, error) {
	if errs := validateResumeActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}
	actorRef := resources.ActorRefFromObjectRef(req.GetActor())
	setSpanActorRefAttributes(ctx, actorRef)

	actor, resumed, err := s.actorWorkflow.ResumeActor(ctx, actorRef)
	if err != nil {
		if errors.Is(err, store.ErrVersionConflict) {
			return nil, status.Error(codes.Aborted, "concurrent update conflict, please retry")
		}
		if errors.Is(err, store.ErrNotFound) {
			return nil, status.Errorf(codes.NotFound, "Actor %s not found", actorRef)
		}
		return nil, err
	}

	setSpanActorAttributes(ctx, actor)
	return &ateapipb.ResumeActorResponse{Actor: actor, Resumed: resumed}, nil
}

func validateResumeActorRequest(ctx context.Context, req *ateapipb.ResumeActorRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_ResumeActorRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) SuspendActor(ctx context.Context, req *ateapipb.SuspendActorRequest) (*ateapipb.SuspendActorResponse, error) {
	if errs := validateSuspendActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}
	actorRef := resources.ActorRefFromObjectRef(req.GetActor())
	setSpanActorRefAttributes(ctx, actorRef)

	actor, err := s.actorWorkflow.SuspendActor(ctx, actorRef)
	if err != nil {
		if errors.Is(err, store.ErrVersionConflict) {
			return nil, status.Error(codes.Aborted, "concurrent update conflict, please retry")
		}
		if errors.Is(err, store.ErrNotFound) {
			return nil, status.Errorf(codes.NotFound, "Actor %s not found", actorRef)
		}
		return nil, err
	}
	setSpanActorAttributes(ctx, actor)
	return &ateapipb.SuspendActorResponse{Actor: actor}, nil
}

func validateSuspendActorRequest(ctx context.Context, req *ateapipb.SuspendActorRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_SuspendActorRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) RevertActor(ctx context.Context, req *ateapipb.RevertActorRequest) (*ateapipb.RevertActorResponse, error) {
	if errs := validateRevertActorRequest(ctx, req); len(errs) > 0 {
		return nil, toGRPCStatusError(errs)
	}
	actorRef := resources.ActorRefFromObjectRef(req.GetActor())
	setSpanActorRefAttributes(ctx, actorRef)

	actor, err := s.actorWorkflow.RevertActor(ctx, actorRef)
	if err != nil {
		if errors.Is(err, store.ErrVersionConflict) {
			return nil, status.Error(codes.Aborted, "concurrent update conflict, please retry")
		}
		if errors.Is(err, store.ErrNotFound) {
			return nil, status.Errorf(codes.NotFound, "Actor %s not found", actorRef)
		}
		return nil, err
	}
	setSpanActorAttributes(ctx, actor)
	return &ateapipb.RevertActorResponse{Actor: actor}, nil
}

func validateRevertActorRequest(ctx context.Context, req *ateapipb.RevertActorRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_RevertActorRequest(ctx, op, nil, req, nil)
}

func validateActorUpdate(ctx context.Context, fldPath *field.Path, newVal, oldVal *ateapipb.Actor, requireStatus bool) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Update}
	errs := Validate_Actor(ctx, op, fldPath, newVal, oldVal)
	if requireStatus {
		// Status is optional in the schema, but is actually required to be set
		// by the server.  If it was specified, it was already validated above,
		// but if it was not specified we need to flag that as an error.
		errs = append(errs, validate.RequiredPointer(ctx, op, fldPath.Child("status"), newVal.GetStatus(), nil)...)
	}
	return errs
}

// This exists only because nested subfield tags are not supported yet.
func ValidateCustom_UpdateActorRequest_Actor(ctx context.Context, op operation.Operation, fldPath *field.Path, actor, _ *ateapipb.Actor) field.ErrorList {
	if actor == nil || actor.Metadata == nil {
		return nil // handled by DV
	}

	// Updates are validated in 2 steps: first the update request and then the
	// resource itself. DV for the request doesn't descend into the resource
	// metadata.  Once DV supports nested subfield tags, this can be changed to
	// something like:
	//   +k8s:subfield(metadata)=+k8s:subfield(atespace)=+k8s:required
	errs := Validate_ResourceMetadata(ctx, op, fldPath.Child("metadata"), actor.Metadata, nil)
	errs = append(errs, validate.RequiredValue(ctx, op, fldPath.Child("metadata", "atespace"), &actor.Metadata.Atespace, nil)...)
	return errs
}

func (s *RPCService) MintActorJWT(ctx context.Context, req *ateapipb.MintActorJWTRequest) (*ateapipb.MintActorJWTResponse, error) {
	if errs := validateMintActorJWTRequest(ctx, req); len(errs) > 0 {
		return nil, status.Error(codes.InvalidArgument, errs.ToAggregate().Error())
	}

	// TODO(authz): Authorization layer needs to check whether the caller has
	// the mintActorJWT permission/relation with this actor.  This could be an
	// atelet (via the relationship of the atelet running the actor), or the
	// egress gateway (via a cluster-level grant?)

	// Verify that this actor exists in the store.  It doesn't need to be
	// running, since we may need to issue JWTs during actor boot / resume.
	dbActor, err := s.impl.GetActor(ctx, resources.ActorRefFromObjectRef(req.GetActor()))
	if errors.Is(err, store.ErrNotFound) {
		return nil, status.Error(codes.NotFound, "actor not found")
	} else if err != nil {
		return nil, fmt.Errorf("while retrieving actor: %w", err)
	}
	if dbActor.GetMetadata().GetUid() != req.GetActorUid() {
		return nil, status.Error(codes.Aborted, "conflict; actor has been deleted and recreated")
	}

	// We only issue tokens with audience bindings.
	if len(req.GetAudience()) == 0 {
		return nil, fmt.Errorf("at least one audience must be requested")
	}

	actorClaims := &actoridjwt.Claims{
		// TODO(identity): This needs to be configurable per-install.  The user
		// needs to make sure that the OIDC discovery docs are accessible at
		// this URL, so that relying parties can verify the JWTs.
		Issuer: "https://api.ate-system.svc",
		// TODO(identity): this format is very likely going to change.
		Subject:    fmt.Sprintf("atespaces:%s:actors:%s", dbActor.GetMetadata().GetAtespace(), dbActor.GetMetadata().GetName()),
		Audiences:  req.GetAudience(),
		Expiration: time.Now().Add(15 * time.Minute),
		NotBefore:  time.Now().Add(-5 * time.Minute),
		IssuedAt:   time.Now(),
		JTI:        rand.Text(),

		Substrate: actoridjwt.SubstrateClaims{
			Atespace:  dbActor.GetMetadata().GetAtespace(),
			ActorName: dbActor.GetMetadata().GetName(),
			ActorUID:  dbActor.GetMetadata().GetUid(),
		},
	}

	actorJWT, err := s.actorIDJWTPool.SignJWT(actorClaims)
	if err != nil {
		return nil, fmt.Errorf("while signing actor JWT: %w", err)
	}

	return &ateapipb.MintActorJWTResponse{
		ActorJwt: actorJWT,
	}, nil
}

func validateMintActorJWTRequest(ctx context.Context, req *ateapipb.MintActorJWTRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_MintActorJWTRequest(ctx, op, nil, req, nil)
}

func (s *RPCService) MintActorCertificate(ctx context.Context, req *ateapipb.MintActorCertificateRequest) (*ateapipb.MintActorCertificateResponse, error) {
	if errs := validateMintActorCertificateRequest(ctx, req); len(errs) > 0 {
		return nil, status.Error(codes.InvalidArgument, errs.ToAggregate().Error())
	}

	// TODO(authz): Authorization layer needs to check whether the caller has
	// the mintActorCertificate permission/relation with this actor.    This
	// could be an atelet (via the relationship of the atelet running the
	// actor), or the egress gateway (via a cluster-level grant?)

	// Check that the caller authenticated with a client certificate --- we
	// should not allow bootstrapping a proof-of-possession credential from a
	// bearer credential.  Note, we don't care that it was a certificate issued
	// by Substrate, or something else.
	//
	// TODO(authz): Perhaps this can be handled with an OpenFGA condition.
	p, ok := peer.FromContext(ctx)
	if !ok {
		return nil, status.Errorf(codes.Unauthenticated, "no peer transport information found")
	}
	tlsInfo, ok := p.AuthInfo.(credentials.TLSInfo)
	if !ok {
		return nil, status.Errorf(codes.Unauthenticated, "unexpected peer transport credentials")
	}
	if len(tlsInfo.State.PeerCertificates) == 0 {
		return nil, status.Errorf(codes.Unauthenticated, "could not verify peer certificate")
	}

	// Verify that this actor exists in the store.  It doesn't need to be
	// running, since we may need to issue certificates during actor boot / resume.
	dbActor, err := s.impl.GetActor(ctx, resources.ActorRefFromObjectRef(req.GetActor()))
	if errors.Is(err, store.ErrNotFound) {
		return nil, status.Error(codes.NotFound, "actor not found")
	} else if err != nil {
		return nil, fmt.Errorf("while retrieving actor: %w", err)
	}
	if dbActor.GetMetadata().GetUid() != req.GetActorUid() {
		return nil, status.Error(codes.Aborted, "conflict; actor has been deleted and recreated")
	}

	// Parse the CSR
	csr, err := x509.ParseCertificateRequest(req.GetCertificateSigningRequest())
	if err != nil {
		return nil, fmt.Errorf("while parsing CSR: %w", err)
	}
	if err := csr.CheckSignature(); err != nil {
		slog.ErrorContext(ctx, "Failed to verify CSR signature", slog.Any("err", err))
		return nil, status.Errorf(codes.InvalidArgument, "Failed to verify CSR signature")
	}

	// TODO(identity): Atunnel certificates should probably have a separate RPC,
	// since different callers will be authorized to get atunnel certificates vs
	// actor self-identity certificates.
	var template *x509.Certificate
	switch req.GetPurpose() {
	case ateapipb.ActorCertificatePurpose_ACTOR_CERTIFICATE_PURPOSE_ATUNNEL:
		template = &x509.Certificate{
			URIs: []*url.URL{resources.ActorSPIFFEID(resources.ActorRef{
				Atespace: dbActor.GetMetadata().GetAtespace(),
				Name:     dbActor.GetMetadata().GetName(),
			})},
			NotBefore:             time.Now().Add(-5 * time.Minute),
			NotAfter:              time.Now().Add(time.Hour),
			KeyUsage:              x509.KeyUsageDigitalSignature,
			ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
			BasicConstraintsValid: true,
			IsCA:                  false,
			Issuer: pkix.Name{
				CommonName: "api.ate-system.svc.cluster.local",
			},
		}
	default:
		return nil, status.Errorf(codes.InvalidArgument, "certificate purpose must be specified")
	}

	err = substratex509.AddActorIdentityToCertificate(
		&substratex509.ActorIdentity{
			Atespace:  dbActor.GetMetadata().GetAtespace(),
			ActorName: dbActor.GetMetadata().GetName(),
			ActorUid:  dbActor.GetMetadata().GetUid(),
			Purpose:   substratex509.ActorIdentityPurposeAtunnel,
		},
		template,
	)
	if err != nil {
		return nil, fmt.Errorf("while adding Substrate extension: %w", err)
	}

	// Sign and return the actor cert.
	chain, err := s.actorIDCAPool.CreateCertificate(template, csr.PublicKey)
	if err != nil {
		return nil, fmt.Errorf("while signing certificate: %w", err)
	}

	return &ateapipb.MintActorCertificateResponse{
		ActorCertificates: chain,
	}, nil
}

func validateMintActorCertificateRequest(ctx context.Context, req *ateapipb.MintActorCertificateRequest) field.ErrorList {
	// Call the generated validation.
	op := operation.Operation{Type: operation.Create}
	return Validate_MintActorCertificateRequest(ctx, op, nil, req, nil)
}