feat: runtime manager

lobby/internal/config/config.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 
+	"galaxy/lobby/internal/domain/engineimage"
 	"galaxy/lobby/internal/telemetry"
 	"galaxy/postgres"
 	"galaxy/redisconn"
@@ -49,6 +50,8 @@ const (
 	raceNameDirectoryBackendEnvVar  = "LOBBY_RACE_NAME_DIRECTORY_BACKEND"
 	raceNameExpirationIntervalEnvVar = "LOBBY_RACE_NAME_EXPIRATION_INTERVAL"
 
+	engineImageTemplateEnvVar = "LOBBY_ENGINE_IMAGE_TEMPLATE"
+
 	otelServiceNameEnvVar                 = "OTEL_SERVICE_NAME"
 	otelTracesExporterEnvVar              = "OTEL_TRACES_EXPORTER"
 	otelMetricsExporterEnvVar             = "OTEL_METRICS_EXPORTER"
@@ -78,6 +81,7 @@ const (
 	defaultGMTimeout                         = 5 * time.Second
 	defaultEnrollmentAutomationInterval      = 30 * time.Second
 	defaultRaceNameExpirationInterval        = time.Hour
+	defaultEngineImageTemplate               = "galaxy/game:" + engineimage.VersionPlaceholder
 	defaultOTelServiceName                   = "galaxy-lobby"
 
 	// RaceNameDirectoryBackendPostgres selects the PostgreSQL-backed
@@ -134,6 +138,9 @@ type Config struct {
 	// every pending_registration whose eligible_until has passed.
 	PendingRegistration PendingRegistrationConfig
 
+	// RuntimeManager configures the Runtime Manager publisher contract.
+	RuntimeManager RuntimeManagerConfig
+
 	// Telemetry configures the process-wide OpenTelemetry runtime.
 	Telemetry TelemetryConfig
 }
@@ -410,6 +417,27 @@ func (cfg PendingRegistrationConfig) Validate() error {
 	return nil
 }
 
+// RuntimeManagerConfig configures the Lobby-side Runtime Manager
+// publisher contract. Lobby resolves the Docker image reference it
+// publishes on `runtime:start_jobs` from a per-game
+// `target_engine_version` and the configured EngineImageTemplate.
+type RuntimeManagerConfig struct {
+	// EngineImageTemplate stores the Docker reference template applied
+	// to a game's `target_engine_version`. The string must contain the
+	// literal placeholder `{engine_version}`; Lobby fails fast at
+	// startup otherwise.
+	EngineImageTemplate string
+}
+
+// Validate reports whether cfg stores a usable Runtime Manager
+// publisher configuration.
+func (cfg RuntimeManagerConfig) Validate() error {
+	if _, err := engineimage.NewResolver(cfg.EngineImageTemplate); err != nil {
+		return fmt.Errorf("engine image template: %w", err)
+	}
+	return nil
+}
+
 // TelemetryConfig configures the Game Lobby Service OpenTelemetry runtime.
 type TelemetryConfig struct {
 	// ServiceName overrides the default OpenTelemetry service name.
@@ -504,6 +532,9 @@ func DefaultConfig() Config {
 		PendingRegistration: PendingRegistrationConfig{
 			Interval: defaultRaceNameExpirationInterval,
 		},
+		RuntimeManager: RuntimeManagerConfig{
+			EngineImageTemplate: defaultEngineImageTemplate,
+		},
 		Telemetry: TelemetryConfig{
 			ServiceName:     defaultOTelServiceName,
 			TracesExporter:  "none",

lobby/internal/config/config_test.go

@@ -40,6 +40,7 @@ func TestDefaultConfig(t *testing.T) {
 	assert.Equal(t, 5*time.Second, cfg.GM.Timeout)
 	assert.Equal(t, 30*time.Second, cfg.EnrollmentAutomation.Interval)
 	assert.Equal(t, time.Hour, cfg.PendingRegistration.Interval)
+	assert.Equal(t, "galaxy/game:{engine_version}", cfg.RuntimeManager.EngineImageTemplate)
 	assert.Equal(t, "galaxy-lobby", cfg.Telemetry.ServiceName)
 	assert.Equal(t, "none", cfg.Telemetry.TracesExporter)
 	assert.Equal(t, "none", cfg.Telemetry.MetricsExporter)
@@ -114,6 +115,7 @@ func TestLoadFromEnvOverrides(t *testing.T) {
 	t.Setenv("LOBBY_NOTIFICATION_INTENTS_STREAM", "alt:intents")
 	t.Setenv("LOBBY_ENROLLMENT_AUTOMATION_INTERVAL", "45s")
 	t.Setenv("LOBBY_RACE_NAME_EXPIRATION_INTERVAL", "15m")
+	t.Setenv("LOBBY_ENGINE_IMAGE_TEMPLATE", "registry.example.com/galaxy/game:{engine_version}")
 	t.Setenv("OTEL_SERVICE_NAME", "galaxy-lobby-test")
 
 	cfg, err := LoadFromEnv()
@@ -129,6 +131,7 @@ func TestLoadFromEnvOverrides(t *testing.T) {
 	assert.Equal(t, "alt:intents", cfg.Redis.NotificationIntentsStream)
 	assert.Equal(t, 45*time.Second, cfg.EnrollmentAutomation.Interval)
 	assert.Equal(t, 15*time.Minute, cfg.PendingRegistration.Interval)
+	assert.Equal(t, "registry.example.com/galaxy/game:{engine_version}", cfg.RuntimeManager.EngineImageTemplate)
 	assert.Equal(t, "galaxy-lobby-test", cfg.Telemetry.ServiceName)
 }
 
@@ -291,6 +294,34 @@ func TestEnrollmentAutomationConfigValidate(t *testing.T) {
 	require.ErrorContains(t, EnrollmentAutomationConfig{}.Validate(), "interval must be positive")
 }
 
+func TestRuntimeManagerConfigValidate(t *testing.T) {
+	t.Parallel()
+
+	require.NoError(t, RuntimeManagerConfig{EngineImageTemplate: "galaxy/game:{engine_version}"}.Validate())
+	require.ErrorContains(t,
+		RuntimeManagerConfig{EngineImageTemplate: ""}.Validate(),
+		"template must not be empty",
+	)
+	require.ErrorContains(t,
+		RuntimeManagerConfig{EngineImageTemplate: "galaxy/game:1.0.0"}.Validate(),
+		"placeholder",
+	)
+}
+
+func TestLoadFromEnvRejectsInvalidEngineImageTemplate(t *testing.T) {
+	clearAllEnv(t)
+	t.Setenv("LOBBY_REDIS_MASTER_ADDR", testRedisAddr)
+	t.Setenv("LOBBY_REDIS_PASSWORD", testRedisSecret)
+	t.Setenv("LOBBY_POSTGRES_PRIMARY_DSN", testDSN)
+	t.Setenv("LOBBY_USER_SERVICE_BASE_URL", testUserBaseURL)
+	t.Setenv("LOBBY_GM_BASE_URL", testGMBaseURL)
+	t.Setenv("LOBBY_ENGINE_IMAGE_TEMPLATE", "galaxy/game:no-placeholder")
+
+	_, err := LoadFromEnv()
+	require.Error(t, err)
+	require.Contains(t, err.Error(), "LOBBY_ENGINE_IMAGE_TEMPLATE")
+}
+
 func TestPendingRegistrationConfigValidate(t *testing.T) {
 	t.Parallel()
 
@@ -367,6 +398,7 @@ func clearAllEnv(t *testing.T) {
 		enrollmentAutomationIntervalEnvVar,
 		raceNameDirectoryBackendEnvVar,
 		raceNameExpirationIntervalEnvVar,
+		engineImageTemplateEnvVar,
 		otelServiceNameEnvVar,
 		otelTracesExporterEnvVar,
 		otelMetricsExporterEnvVar,

lobby/internal/config/env.go

@@ -108,6 +108,8 @@ func LoadFromEnv() (Config, error) {
 		return Config{}, err
 	}
 
+	cfg.RuntimeManager.EngineImageTemplate = stringEnv(engineImageTemplateEnvVar, cfg.RuntimeManager.EngineImageTemplate)
+
 	cfg.Telemetry.ServiceName = stringEnv(otelServiceNameEnvVar, cfg.Telemetry.ServiceName)
 	cfg.Telemetry.TracesExporter = normalizeExporterValue(stringEnv(otelTracesExporterEnvVar, cfg.Telemetry.TracesExporter))
 	cfg.Telemetry.MetricsExporter = normalizeExporterValue(stringEnv(otelMetricsExporterEnvVar, cfg.Telemetry.MetricsExporter))

lobby/internal/config/validation.go

@@ -41,6 +41,9 @@ func (cfg Config) Validate() error {
 	if err := cfg.PendingRegistration.Validate(); err != nil {
 		return fmt.Errorf("%s: %w", raceNameExpirationIntervalEnvVar, err)
 	}
+	if err := cfg.RuntimeManager.Validate(); err != nil {
+		return fmt.Errorf("%s: %w", engineImageTemplateEnvVar, err)
+	}
 	if err := cfg.Telemetry.Validate(); err != nil {
 		return err
 	}