docker files fixes from liaqat

src/Managing.Infrastructure.MongoDb/MongoHelpers.cs

@@ -0,0 +1,20 @@
+using MongoDB.Bson;
+using MongoDB.Driver;
+
+namespace Managing.Infrastructure.MongoDb
+{
+    public static class MongoHelpers
+    {
+        public static async Task EnsureIndexExists(this IMongoDatabase database, string collectionName, string indexName)
+        {
+            var collection = database.GetCollection<BsonDocument>(collectionName);
+            var index = new BsonDocument
+            {
+                {indexName, 1}
+            };
+
+            var indexModel = new CreateIndexModel<BsonDocument>(index, new CreateIndexOptions { Unique = true });
+            await collection.Indexes.CreateOneAsync(indexModel).ConfigureAwait(false);
+        }
+    }
+}