Added CredentialsSuppliers

Author: artem-v

services-api/src/main/java/io/scalecube/services/auth/CredentialsSuppliers.java

@@ -0,0 +1,17 @@
+package io.scalecube.services.auth;
+
+import java.util.List;
+
+public class CredentialsSuppliers {
+
+  private final CredentialsSupplier credentialsSupplier;
+
+  public CredentialsSuppliers(CredentialsSupplier credentialsSupplier) {
+    this.credentialsSupplier = credentialsSupplier;
+  }
+
+  public CredentialsSupplier forServiceRole(String serviceRole) {
+    return (service, allowedRoles) ->
+        credentialsSupplier.credentials(service, List.of(serviceRole));
+  }
+}