Allow ConfigureSources to accept the instance of MetricSourceOptions that we want to use

Remove the addition of default metric sources

Author: Dean Ward

src/StackExchange.Metrics/DependencyInjection/MetricsCollectorBuilder.cs

@@ -18,11 +18,6 @@ public MetricsCollectorBuilder(IServiceCollection services)
 
             Options = new MetricsCollectorOptions();
             Services = services;
-
-            this.ConfigureSources(
-                o => o.DefaultTags.Add("host", Environment.MachineName)
-            );
-            this.AddDefaultSources();
         }
 
         public IServiceCollection Services { get; }

src/StackExchange.Metrics/DependencyInjection/MetricsCollectorBuilderExtensions.cs

@@ -113,11 +113,21 @@ public static IMetricsCollectorBuilder ConfigureSources(this IMetricsCollectorBu
         {
             var options = new MetricSourceOptions();
             action?.Invoke(options);
+            return builder.ConfigureSources(options);
+        }
+
+        /// <summary>
+        /// Configures the default <see cref="MetricSourceOptions"/> used for <see cref="MetricSource"/> instances
+        /// passed to the collector.
+        /// </summary>
+        public static IMetricsCollectorBuilder ConfigureSources(this IMetricsCollectorBuilder builder, MetricSourceOptions options)
+        {
             builder.Services.RemoveAll<MetricSourceOptions>();
             builder.Services.AddSingleton(options);
             return builder;
         }
 
+
         /// <summary>
         /// Registers an <see cref="MetricSource" /> for use with the collector.
         /// </summary>

src/StackExchange.Metrics/DependencyInjection/ServiceCollectionExtensions.cs

@@ -1,7 +1,9 @@
 using Microsoft.Extensions.Hosting;
 using StackExchange.Metrics;
 using StackExchange.Metrics.DependencyInjection;
+#if NETCOREAPP
 using StackExchange.Metrics.Infrastructure;
+#endif
 
 namespace Microsoft.Extensions.DependencyInjection
 {

src/StackExchange.Metrics/MetricSourceOptions.cs

@@ -35,7 +35,10 @@ public MetricSourceOptions()
             MetricNameValidator = s_defaultMetricNameValidator;
             TagNameValidator = s_defaultTagNameValidator;
             TagValueValidator = s_defaultTagValueValidator;
-            DefaultTags = new TagDictionary(this);
+            DefaultTags = new TagDictionary(this)
+            {
+                ["host"] = Environment.MachineName
+            };
         }
 
         /// <summary>

tests/StackExchange.Metrics.Tests/MetricsCollectorBuilderTests.cs

@@ -20,33 +20,6 @@ public MetricsCollectorBuilderTests(ITestOutputHelper output)
             _output = output;
         }
 
-        [Fact]
-        public void DefaultOptions_HasHostTag()
-        {
-            var services = CreateServices();
-            var builder = new MetricsCollectorBuilder(services);
-
-            var serviceProvider = services.BuildServiceProvider();
-            var options = builder.Build(serviceProvider);
-
-            var sourceOptions = serviceProvider.GetRequiredService<MetricSourceOptions>();
-
-            Assert.Contains(
-                sourceOptions.DefaultTags, x => x.Key == "host" && x.Value == Environment.MachineName.ToLower()
-            );
-        }
-
-
-        [Fact]
-        public void DefaultOptions_HasDefaultSources()
-        {
-            var options = CreateOptions();
-
-            Assert.Contains(options.Sources, x => x is AspNetMetricSource);
-            Assert.Contains(options.Sources, x => x is RuntimeMetricSource);
-            Assert.Contains(options.Sources, x => x is ProcessMetricSource);
-        }
-
         [Fact]
         public void Endpoints_LocalAddedByDefault()
         {