Added first app template

backend/login-counter/app.Configuration/ConfigurationExtensions.cs

@@ -0,0 +1,36 @@
+using Microsoft.Extensions.Configuration;
+using System;
+
+namespace app.Configuration {
+    public static class ConfigurationExtensions {
+        public static TSetting GetSetting<TSetting>(this IConfiguration config, string sectionName)
+            where TSetting : new() {
+            var settings = new TSetting();
+            config.GetSection(sectionName).Bind(settings);
+            return settings;
+        }
+
+        public static string GetDbConnectionString(this IConfiguration config, string sectionName) {
+            var connectionString = config[$"{sectionName}:ConnectionString"];
+
+            if (string.IsNullOrEmpty(connectionString))
+                throw new Exception($"ConnectionString is not set! SectionName:{sectionName}");
+
+            var dbCredentials = config[$"{sectionName}:Credentials"];
+
+            if (!string.IsNullOrEmpty(dbCredentials))
+                connectionString += dbCredentials;
+
+            return connectionString;
+        }
+
+        public static string GetCustomer(this IConfiguration config) {
+            return config["CUSTOMER"];
+        }
+
+        public static string GetComputerName(this IConfiguration config) {
+            return config["COMPUTERNAME"];
+        }
+
+    }
+}