command line arguments handling

src/cartservice/CartServiceImpl.cs

@@ -2,6 +2,7 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
+using cartservice.interfaces;
 using Grpc.Core;
 using Hipstershop;
 using static Hipstershop.CartService;
@@ -11,65 +12,29 @@ namespace cartservice
     // Cart wrapper to deal with grpc communication
     internal class CartServiceImpl : CartServiceBase
     {
-        private CartStore cartStore;
+        private ICartStore cartStore;
+        private readonly static Empty Empty = new Empty();
 
-        public CartServiceImpl(CartStore cartStore)
+        public CartServiceImpl(ICartStore cartStore)
         {
             this.cartStore = cartStore;
         }
 
-        public override Task<Empty> AddItem(AddItemRequest request, Grpc.Core.ServerCallContext context)
+        public async override Task<Empty> AddItem(AddItemRequest request, Grpc.Core.ServerCallContext context)
         {
-            cartStore.AddItem(request.UserId, request.Item.ProductId, request.Item.Quantity);
+            await cartStore.AddItemAsync(request.UserId, request.Item.ProductId, request.Item.Quantity);
-            return Task.FromResult(new Empty());
+            return Empty;
         }
 
-        public override Task<Empty> EmptyCart(EmptyCartRequest request, ServerCallContext context)
+        public async override Task<Empty> EmptyCart(EmptyCartRequest request, ServerCallContext context)
         {
-            cartStore.EmptyCart(request.UserId);
+            await cartStore.EmptyCartAsync(request.UserId);
-            return Task.FromResult(new Empty());
+            return Empty;
         }
 
-        public override Task<Hipstershop.Cart> GetCart(GetCartRequest request, ServerCallContext context)
+        public async override Task<Hipstershop.Cart> GetCart(GetCartRequest request, ServerCallContext context)
         {
-            var cart = cartStore.GetCart(request.UserId);
+            return await cartStore.GetCartAsync(request.UserId);
-            return Task.FromResult(cart.ToHipsterCart());
-        }
-    }
-
-    internal class CartStore
-    {
-        // Maps between user and their cart
-        private ConcurrentDictionary<string, Cart> userCartItems = new ConcurrentDictionary<string, Cart>();
-
-        public void AddItem(string userId, string productId, int quantity)
-        {
-            Cart cart;
-            if (!userCartItems.TryGetValue(userId, out cart))
-            {
-                cart = new Cart(userId);
-            }
-            else
-            {
-                cart = userCartItems[userId];
-            }
-            cart.AddItem(productId, quantity);
-        }
-
-        public void EmptyCart(string userId)
-        {
-            Cart cart;
-            if (userCartItems.TryGetValue(userId, out cart))
-            {
-                cart.EmptyCart();
-            }
-        }
-
-        public Cart GetCart(string userId)
-        {
-            Cart cart = null;
-            userCartItems.TryGetValue(userId, out cart);
-            return cart;
         }
     }
 

src/cartservice/Program.cs

@@ -1,29 +1,41 @@
 using System;
+using System.IO;
+using cartservice.cartstore;
 using CommandLine;
 using Grpc.Core;
+using Microsoft.Extensions.Configuration;
 
 namespace cartservice
 {
     class Program
     {
+        const string CART_SERVICE_ADDRESS = "CART_SERVICE_ADDR";
+        const string REDIS_ADDRESS = "REDIS_ADDR";
+
         [Verb("start", HelpText = "Starts the server listening on provided port")]
         class ServerOptions
         {
+            [Option('h', "hostname", HelpText = "The ip on which the server is running. If not provided, CART_SERVICE_ADDR environment variable value will be used. If not defined, localhost is used")]
+            public string Host { get; set; }
 
             [Option('p', "port", HelpText = "The port on for running the server", Required = true)]
             public int Port { get; set; }
+
+            [Option('r', "redis", HelpText = "The ip of redis cache")]
+            public string Redis { get; set; }
+
         }
 
-        static object StartServer(string host, int port)
+        static object StartServer(string host, int port, string redisAddress)
         {
-            var store = new CartStore();
+            var store = new RedisCartStore(redisAddress);
             Server server = new Server
             {
                 Services = { Hipstershop.CartService.BindService(new CartServiceImpl(store)) },
                 Ports = { new ServerPort(host, port, ServerCredentials.Insecure) }
             };
 
-            Console.WriteLine("Cart server is listening on port " + port);
+            Console.WriteLine($"Cart server is listening at {host}:{port}");
             Console.WriteLine("Press any key to stop the server...");
             server.Start();
 
@@ -33,6 +45,7 @@ namespace cartservice
 
             return null;
         }
+
         static void Main(string[] args)
         {
             if (args.Length == 0)
@@ -45,15 +58,34 @@ namespace cartservice
             {
                 case "start":
                     Parser.Default.ParseArguments<ServerOptions>(args).MapResult(
-                        (ServerOptions options) => StartServer("localhost", options.Port),
+                        (ServerOptions options) => 
+                        {
+                            string host = options.Host;
+                            if (string.IsNullOrEmpty(host))
+                            {
+                                Console.WriteLine($"Reading host address from {CART_SERVICE_ADDRESS} environment variable...");
+                                host = Environment.GetEnvironmentVariable(CART_SERVICE_ADDRESS);
+                                if (string.IsNullOrEmpty(host))
+                                {
+                                    Console.WriteLine("Setting the host to 127.0.0.1");
+                                    host = "127.0.0.1";
+                                }
+                            }
+
+                            string redis = options.Redis;
+                            if (string.IsNullOrEmpty(redis))
+                            {
+                                Console.WriteLine("Reading redis cache address from environment variable");
+                                redis = Environment.GetEnvironmentVariable(REDIS_ADDRESS);
+                            }
+                            return StartServer(host, options.Port, redis);
+                        },
                         errs => 1);
                     break;
                 default:
                     Console.WriteLine("Invalid command");
                     break;
             }
-
-            Console.WriteLine("Hello World!");
         }
     }
 }

src/cartservice/cartservice.csproj

@@ -11,6 +11,9 @@
     <PackageReference Include="Google.Protobuf.Tools" Version="3.5.1" />
     <PackageReference Include="grpc" Version="1.12.0" />
     <PackageReference Include="grpc.tools" Version="1.12.0" />
+    <PackageReference Include="Microsoft.Extensions.Configuration" Version="2.1.1" />
+    <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="2.1.1" />
+    <PackageReference Include="StackExchange.Redis" Version="1.2.6" />
   </ItemGroup>
 
 </Project>