chore(shard-manager): provide metadata in constructor (#7711)

**What changed?**
Refactoring for #7712:
Providing shard executor metadata to the constructor instead of
Initalising this separately.
In addition, unifying panic -> logger.Fatal as we do in other cases.

**Why?**

+Better readability as code is more aligned with other usages of
log.Fatal.
Passing metadata to constructor allows to avoid partial structure
initialization.

**How did you test it?**
go test -v ./service/matching/handler

**Potential risks**

**Release notes**

**Documentation Changes**

Signed-off-by: Jan Kisel <dkrot@uber.com>

Author: dkrotx

service/matching/handler/engine.go

@@ -198,31 +198,31 @@ func (e *matchingEngineImpl) setupExecutor(shardDistributorExecutorClient execut
 	}
 	e.taskListsFactory = taskListFactory
 
+	// Get the IP address to advertise to external services
+	// This respects bindOnLocalHost config (127.0.0.1 for local dev, external IP for production)
+	hostIP, err := rpc.GetListenIP(e.config.RPCConfig)
+	if err != nil {
+		e.logger.Fatal("Failed to get listen IP", tag.Error(err))
+	}
+
 	params := executorclient.Params[tasklist.ShardProcessor]{
 		ExecutorClient:        shardDistributorExecutorClient,
 		MetricsScope:          e.metricsScope,
 		Logger:                e.logger,
 		ShardProcessorFactory: taskListFactory,
 		Config:                cfg,
 		TimeSource:            e.timeSource,
+		Metadata: map[string]string{
+			"tchannel": fmt.Sprintf("%d", e.config.RPCConfig.Port),
+			"grpc":     fmt.Sprintf("%d", e.config.RPCConfig.GRPCPort),
+			"hostIP":   hostIP.String(),
+		},
 	}
 	executor, err := executorclient.NewExecutor[tasklist.ShardProcessor](params)
 	if err != nil {
-		panic(err)
+		e.logger.Fatal("Failed to create new executor", tag.Error(err))
 	}
 
-	// Get the IP address to advertise to external services
-	// This respects bindOnLocalHost config (127.0.0.1 for local dev, external IP for production)
-	hostIP, err := rpc.GetListenIP(e.config.RPCConfig)
-	if err != nil {
-		e.logger.Fatal("Failed to get listen IP", tag.Error(err))
-	}
-
-	executor.SetMetadata(map[string]string{
-		"tchannel": fmt.Sprintf("%d", e.config.RPCConfig.Port),
-		"grpc":     fmt.Sprintf("%d", e.config.RPCConfig.GRPCPort),
-		"hostIP":   hostIP.String(),
-	})
 	e.executor = executor
 }
 

service/sharddistributor/client/executorclient/clientimpl.go

@@ -138,10 +138,10 @@ func (e *executorImpl[SP]) Stop() {
 }
 
 func (e *executorImpl[SP]) GetShardProcess(ctx context.Context, shardID string) (SP, error) {
-	shardProcess, ok := e.managedProcessors.Load(shardID)
 	e.processorsToLastUse.Store(shardID, e.timeSource.Now())
-	if !ok {
 
+	shardProcess, ok := e.managedProcessors.Load(shardID)
+	if !ok {
 		if e.getMigrationMode() == types.MigrationModeLOCALPASSTHROUGH {
 			// Fail immediately if we are in LOCAL_PASSTHROUGH mode
 			var zero SP
@@ -162,6 +162,7 @@ func (e *executorImpl[SP]) GetShardProcess(ctx context.Context, shardID string)
 			return zero, fmt.Errorf("shard process not found for shard ID: %s", shardID)
 		}
 	}
+
 	return shardProcess.processor, nil
 }