Add `IAdditionalConfigurationSource` to load the agent-config from the config center. (#151)

src/SkyApm.Agent.AspNet/Extensions/ServiceCollectionExtensions.cs

@@ -47,7 +47,8 @@ namespace SkyApm.Agent.AspNet.Extensions
             services.AddSingleton<IConfigAccessor, ConfigAccessor>();
             services.AddSingleton<IEnvironmentProvider, HostingEnvironmentProvider>();
             services.AddSingleton<InstrumentRequestCallback>();
-            
+            services.AddSingleton<IConfigurationFactory, ConfigurationFactory>();
+
             services.AddSingleton<ITracingContext, Tracing.TracingContext>();
             services.AddSingleton<ICarrierPropagator, CarrierPropagator>();
             services.AddSingleton<ICarrierFormatter, Sw3CarrierFormatter>();
@@ -61,19 +62,19 @@ namespace SkyApm.Agent.AspNet.Extensions
             services.AddSingleton<IUniqueIdParser, UniqueIdParser>();
             services.AddSingleton<ISegmentContextMapper, SegmentContextMapper>();
             services.AddSingleton<IBase64Formatter, Base64Formatter>();
-            
+
             services.AddSingleton<SimpleCountSamplingInterceptor>();
             services.AddSingleton<ISamplingInterceptor>(p => p.GetService<SimpleCountSamplingInterceptor>());
             services.AddSingleton<IExecutionService>(p => p.GetService<SimpleCountSamplingInterceptor>());
             services.AddSingleton<ISamplingInterceptor, RandomSamplingInterceptor>();
-            
+
             services.AddSingleton<ISkyApmClientV5, SkyApmClientV5>();
             services.AddSingleton<ISegmentReporter, SegmentReporter>();
             services.AddSingleton<ConnectionManager>();
             services.AddSingleton<IPingCaller, PingCaller>();
             services.AddSingleton<IServiceRegister, ServiceRegister>();
             services.AddSingleton<IExecutionService, ConnectService>();
-            
+
             services.AddSingleton<ILoggerFactory, DefaultLoggerFactory>();
             return services;
         }

src/SkyApm.Agent.AspNetCore/Extensions/ServiceCollectionExtensions.cs

@@ -57,6 +57,7 @@ namespace SkyApm.Agent.AspNetCore
             services.AddSingleton<IRuntimeEnvironment>(RuntimeEnvironment.Instance);
             services.AddSingleton<TracingDiagnosticProcessorObserver>();
             services.AddSingleton<IConfigAccessor, ConfigAccessor>();
+            services.AddSingleton<IConfigurationFactory, ConfigurationFactory>();
             services.AddSingleton<IHostedService, InstrumentationHostedService>();
             services.AddSingleton<IEnvironmentProvider, HostingEnvironmentProvider>();
             services.AddTracing().AddSampling().AddGrpcTransport().AddLogging();

src/SkyApm.Utilities.Configuration/ConfigAccessor.cs

@@ -22,40 +22,15 @@ using System.Reflection;
 using Microsoft.Extensions.Configuration;
 using SkyApm.Config;
 
-// ReSharper disable StringLiteralTypo
 namespace SkyApm.Utilities.Configuration
 {
     public class ConfigAccessor : IConfigAccessor
     {
-        private const string CONFIG_FILE_PATH_COMPATIBLE = "SKYWALKING__CONFIG__PATH";
-        private const string CONFIG_FILE_PATH = "SKYAPM__CONFIG__PATH";
         private readonly IConfiguration _configuration;
 
-        public ConfigAccessor(IEnvironmentProvider environmentProvider)
+        public ConfigAccessor(IConfigurationFactory factory)
         {
-            var builder = new ConfigurationBuilder();
-
-            builder.AddSkyWalkingDefaultConfig();
-
-            builder.AddJsonFile("appsettings.json", true).AddJsonFile($"appsettings.{environmentProvider.EnvironmentName}.json", true);
-
-            builder.AddJsonFile("skywalking.json", true).AddJsonFile($"skywalking.{environmentProvider.EnvironmentName}.json", true);
-            
-            builder.AddJsonFile("skyapm.json", true).AddJsonFile($"skyapm.{environmentProvider.EnvironmentName}.json", true);
-
-            if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH_COMPATIBLE)))
-            {
-                builder.AddJsonFile(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH_COMPATIBLE), false);
-            }
-            
-            if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH)))
-            {
-                builder.AddJsonFile(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH), false);
-            }
-
-            builder.AddEnvironmentVariables();
-
-            _configuration = builder.Build();
+            _configuration = factory.Create();
         }
 
         public T Get<T>() where T : class, new()
@@ -72,7 +47,9 @@ namespace SkyApm.Utilities.Configuration
             return _configuration.GetSection(config.GetSections()).GetValue<T>(key);
         }
 
-        //hign performance
+        /// <summary>
+        /// high performance
+        /// </summary>
         private static class New<T> where T : new()
         {
             public static readonly Func<T> Instance = Expression.Lambda<Func<T>>

src/SkyApm.Utilities.Configuration/ConfigurationFactory.cs

+/*
+ * Licensed to the SkyAPM under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The SkyAPM licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using System;
+using System.Collections.Generic;
+using Microsoft.Extensions.Configuration;
+
+// ReSharper disable StringLiteralTypo
+namespace SkyApm.Utilities.Configuration
+{
+    public class ConfigurationFactory : IConfigurationFactory
+    {
+        private const string CONFIG_FILE_PATH_COMPATIBLE = "SKYWALKING__CONFIG__PATH";
+        private const string CONFIG_FILE_PATH = "SKYAPM__CONFIG__PATH";
+        private readonly IEnvironmentProvider _environmentProvider;
+        private readonly IEnumerable<IAdditionalConfigurationSource> _additionalConfigurations;
+
+        public ConfigurationFactory(IEnvironmentProvider environmentProvider,
+            IEnumerable<IAdditionalConfigurationSource> additionalConfigurations)
+        {
+            _environmentProvider = environmentProvider;
+            _additionalConfigurations = additionalConfigurations;
+        }
+
+        public IConfiguration Create()
+        {
+            var builder = new ConfigurationBuilder();
+
+            builder.AddSkyWalkingDefaultConfig();
+
+            builder.AddJsonFile("appsettings.json", true)
+                .AddJsonFile($"appsettings.{_environmentProvider.EnvironmentName}.json", true);
+
+            builder.AddJsonFile("skywalking.json", true)
+                .AddJsonFile($"skywalking.{_environmentProvider.EnvironmentName}.json", true);
+
+            builder.AddJsonFile("skyapm.json", true)
+                .AddJsonFile($"skyapm.{_environmentProvider.EnvironmentName}.json", true);
+
+            if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH_COMPATIBLE)))
+            {
+                builder.AddJsonFile(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH_COMPATIBLE), false);
+            }
+
+            if (!string.IsNullOrEmpty(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH)))
+            {
+                builder.AddJsonFile(Environment.GetEnvironmentVariable(CONFIG_FILE_PATH), false);
+            }
+
+            builder.AddEnvironmentVariables();
+
+            foreach (var additionalConfiguration in _additionalConfigurations)
+            {
+                additionalConfiguration.Load(builder);
+            }
+
+            return builder.Build();
+        }
+    }
+}
\ No newline at end of file

src/SkyApm.Utilities.Configuration/IAdditionalConfigurationSource.cs

+/*
+ * Licensed to the SkyAPM under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The SkyAPM licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using Microsoft.Extensions.Configuration;
+
+namespace SkyApm.Utilities.Configuration
+{
+    public interface IAdditionalConfigurationSource
+    {
+        void Load(ConfigurationBuilder builder);
+    }
+}
\ No newline at end of file

src/SkyApm.Utilities.Configuration/IConfigurationFactory.cs

+/*
+ * Licensed to the SkyAPM under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The SkyAPM licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+using Microsoft.Extensions.Configuration;
+
+namespace SkyApm.Utilities.Configuration
+{
+    public interface IConfigurationFactory
+    {
+        IConfiguration Create();
+    }
+}
\ No newline at end of file