Support specifying environment variables for the Webpack dev middleware Node instance. Resolves aspnet#311.

Author: SteveSandersonMS

src/Microsoft.AspNetCore.SpaServices/Webpack/WebpackDevMiddleware.cs

@@ -47,6 +47,14 @@ public static void UseWebpackDevMiddleware(
                 nodeServicesOptions.ProjectPath = options.ProjectPath;
             }
 
+            if (options.EnvironmentVariables != null)
+            {
+                foreach (var kvp in options.EnvironmentVariables)
+                {
+                    nodeServicesOptions.EnvironmentVariables[kvp.Key] = kvp.Value;
+                }
+            }
+
             var nodeServices = NodeServicesFactory.CreateNodeServices(nodeServicesOptions);
 
             // Get a filename matching the middleware Node script

src/Microsoft.AspNetCore.SpaServices/Webpack/WebpackDevMiddlewareOptions.cs

@@ -1,3 +1,5 @@
+using System.Collections.Generic;
+
 namespace Microsoft.AspNetCore.SpaServices.Webpack
 {
     public class WebpackDevMiddlewareOptions
@@ -7,5 +9,6 @@ public class WebpackDevMiddlewareOptions
         public bool ReactHotModuleReplacement { get; set; }
         public string ConfigFile { get; set; }
         public string ProjectPath { get; set; }
+        public IDictionary<string, string> EnvironmentVariables { get; set; }
     }
 }