go/worker/registration: Support specifying only entity ID

.changelog/5764.cfg.md

@@ -0,0 +1,5 @@
+Support only `entity_id` to be specified in configuration
+
+Instead of the need to specify the path to the entire entity descriptor, the
+node configuration can now specify only `registration.entity_id`, the entity
+public key.

go/common/predicates.go

@@ -1,12 +1,21 @@
 package common
 
-// ExactlyOneTrue returns true iff exactly one of the passed conditions is true.
-func ExactlyOneTrue(conds ...bool) bool {
+func countTrue(conds ...bool) int {
 	total := 0
 	for _, c := range conds {
 		if c {
 			total++
 		}
 	}
-	return total == 1
+	return total
+}
+
+// ExactlyOneTrue returns true iff exactly one of the passed conditions is true.
+func ExactlyOneTrue(conds ...bool) bool {
+	return countTrue(conds...) == 1
+}
+
+// AtMostOneTrue returns true iff at most one of the passed conditions is true.
+func AtMostOneTrue(conds ...bool) bool {
+	return countTrue(conds...) <= 1
 }

go/oasis-test-runner/oasis/byzantine.go

@@ -2,7 +2,6 @@ package oasis
 
 import (
 	"fmt"
-	"path/filepath"
 	"strconv"
 
 	beacon "github.com/oasisprotocol/oasis-core/go/beacon/api"
@@ -74,8 +73,8 @@ func (worker *Byzantine) ModifyConfig() error {
 	worker.AddSeedNodesToConfig()
 
 	if !worker.entity.isDebugTestEntity {
-		dir := worker.entity.dir.String()
-		worker.Config.Registration.Entity = filepath.Join(dir, "entity.json")
+		entityID, _ := worker.entity.ID().MarshalText() // Cannot fail.
+		worker.Config.Registration.EntityID = string(entityID)
 	}
 
 	return nil

go/oasis-test-runner/oasis/compute.go

@@ -159,8 +159,8 @@ func (worker *Compute) ModifyConfig() error {
 	worker.Config.P2P.Port = worker.p2pPort
 
 	if !worker.entity.isDebugTestEntity {
-		dir := worker.entity.dir.String()
-		worker.Config.Registration.Entity = filepath.Join(dir, "entity.json")
+		entityID, _ := worker.entity.ID().MarshalText() // Cannot fail.
+		worker.Config.Registration.EntityID = string(entityID)
 	}
 
 	worker.Config.Mode = config.ModeCompute

go/oasis-test-runner/oasis/keymanager.go

@@ -288,8 +288,8 @@ func (km *Keymanager) ModifyConfig() error {
 	km.Config.P2P.Port = km.p2pPort
 
 	if !km.entity.isDebugTestEntity {
-		dir := km.entity.dir.String()
-		km.Config.Registration.Entity = filepath.Join(dir, "entity.json")
+		entityID, _ := km.entity.ID().MarshalText() // Cannot fail.
+		km.Config.Registration.EntityID = string(entityID)
 	}
 
 	km.Config.Mode = config.ModeKeyManager

go/oasis-test-runner/oasis/validator.go

@@ -93,8 +93,8 @@ func (val *Validator) ModifyConfig() error {
 	val.Config.P2P.Port = val.p2pPort
 
 	if !val.entity.isDebugTestEntity {
-		dir := val.entity.dir.String()
-		val.Config.Registration.Entity = filepath.Join(dir, "entity.json")
+		entityID, _ := val.entity.ID().MarshalText() // Cannot fail.
+		val.Config.Registration.EntityID = string(entityID)
 	}
 
 	if len(val.sentries) > 0 {

go/worker/registration/config/config.go

@@ -1,20 +1,46 @@
 // Package config implements global configuration options.
 package config
 
+import (
+	"fmt"
+
+	"github.com/oasisprotocol/oasis-core/go/common"
+	"github.com/oasisprotocol/oasis-core/go/common/crypto/signature"
+)
+
 // Config is the registration worker configuration structure.
 type Config struct {
 	// Entity to use as the node owner in registrations (path to the JSON file).
 	Entity string `yaml:"entity"`
+
+	// EntityID to use as the node owner in registrations (public key).
+	EntityID string `yaml:"entity_id"`
 }
 
 // Validate validates the configuration settings.
 func (c *Config) Validate() error {
+	// Ensure only one of Entity/EntityID is set.
+	if !common.AtMostOneTrue(
+		c.Entity != "",
+		c.EntityID != "",
+	) {
+		return fmt.Errorf("only one of `entity` and `entity_id` must be set")
+	}
+
+	// Ensure the entity ID is valid if passed.
+	if c.EntityID != "" {
+		var id signature.PublicKey
+		if err := id.UnmarshalText([]byte(c.EntityID)); err != nil {
+			return fmt.Errorf("malformed entity ID: %w", err)
+		}
+	}
 	return nil
 }
 
 // DefaultConfig returns the default configuration settings.
 func DefaultConfig() Config {
 	return Config{
-		Entity: "",
+		Entity:   "",
+		EntityID: "",
 	}
 }

go/worker/registration/worker.go

@@ -1025,24 +1025,34 @@ func GetRegistrationSigner(identity *identity.Identity) (signature.PublicKey, si
 		return testEntity.ID, testSigner, nil
 	}
 
-	// Load the registration entity descriptor.
-	f := config.GlobalConfig.Registration.Entity
-	if f == "" {
+	// Determine the owning entity ID.
+	cfgEntityFn := config.GlobalConfig.Registration.Entity
+	cfgEntityID := config.GlobalConfig.Registration.EntityID
+
+	switch {
+	case cfgEntityFn != "":
+		// Attempt to load the entity descriptor.
+		entity, err := entity.LoadDescriptor(cfgEntityFn)
+		if err != nil {
+			return defaultPk, nil, fmt.Errorf("worker/registration: failed to load entity descriptor: %w", err)
+		}
+
+		return entity.ID, identity.NodeSigner, nil
+	case cfgEntityID != "":
+		// Attempt to parse the entity ID.
+		var entityID signature.PublicKey
+		if err := entityID.UnmarshalText([]byte(cfgEntityID)); err != nil {
+			return defaultPk, nil, fmt.Errorf("worker/registration: malformed entity ID: %w", err)
+		}
+
+		return entityID, identity.NodeSigner, nil
+	default:
 		// TODO: There are certain configurations (eg: the test client) that
 		// spin up workers, which require a registration worker, but don't
 		// need it, and do not have an owning entity.  The registration worker
 		// should not be initialized in this case.
 		return defaultPk, nil, nil
 	}
-
-	// Attempt to load the entity descriptor.
-	entity, err := entity.LoadDescriptor(f)
-	if err != nil {
-		return defaultPk, nil, fmt.Errorf("worker/registration: failed to load entity descriptor: %w", err)
-	}
-
-	// Registrations are always node-signed.
-	return entity.ID, identity.NodeSigner, nil
 }
 
 // New constructs a new worker node registration service.