Fix: IoT does not work in server mode (#3644)

Closes #1631

moto/server.py

@@ -34,6 +34,13 @@ UNSIGNED_REQUESTS = {
 }
 UNSIGNED_ACTIONS = {"AssumeRoleWithSAML": ("sts", "us-east-1")}
 
+# Some services have v4 signing names that differ from the backend service name/id.
+SIGNING_ALIASES = {
+    "eventbridge": "events",
+    "execute-api": "iot",
+    "iotdata": "data.iot",
+}
+
 
 class DomainDispatcherApplication(object):
     """
@@ -74,6 +81,7 @@ class DomainDispatcherApplication(object):
             try:
                 credential_scope = auth.split(",")[0].split()[1]
                 _, _, region, service, _ = credential_scope.split("/")
+                service = SIGNING_ALIASES.get(service.lower(), service)
             except ValueError:
                 # Signature format does not match, this is exceptional and we can't
                 # infer a service-region. A reduced set of services still use
@@ -94,11 +102,6 @@ class DomainDispatcherApplication(object):
                 # S3 is the last resort when the target is also unknown
                 service, region = DEFAULT_SERVICE_REGION
 
-        if service == "EventBridge":
-            # Go SDK uses 'EventBridge' in the SigV4 request instead of 'events'
-            # see https://github.com/spulec/moto/issues/3494
-            service = "events"
-
         if service == "dynamodb":
             if environ["HTTP_X_AMZ_TARGET"].startswith("DynamoDBStreams"):
                 host = "dynamodbstreams"