CSHARP-4718: Enable Container and kubernetes awareness (#1295)

Author: adelinowona

src/MongoDB.Driver.Core/Core/Connections/ClientDocumentHelper.cs

@@ -19,6 +19,7 @@
 using System.Text.RegularExpressions;
 using MongoDB.Bson;
 using MongoDB.Driver.Core.Configuration;
+using MongoDB.Driver.Core.Misc;
 
 namespace MongoDB.Driver.Core.Connections
 {
@@ -30,17 +31,31 @@ internal class ClientDocumentHelper
         private static Lazy<BsonDocument> __envDocument;
         private static Lazy<BsonDocument> __osDocument;
         private static Lazy<string> __platformString;
+        private static IEnvironmentVariableProvider __environmentVariableProvider;
+        private static IFileSystemProvider __fileSystemProvider;
 
         private static void Initialize()
         {
             __driverDocument = new Lazy<BsonDocument>(CreateDriverDocument);
             __envDocument = new Lazy<BsonDocument>(CreateEnvDocument);
             __osDocument = new Lazy<BsonDocument>(CreateOSDocument);
             __platformString = new Lazy<string>(GetPlatformString);
+            __environmentVariableProvider = EnvironmentVariableProvider.Instance;
+            __fileSystemProvider = FileSystemProvider.Instance;
         }
 
         static ClientDocumentHelper() => Initialize();
 
+        internal static void SetEnvironmentVariableProvider(IEnvironmentVariableProvider environmentVariableProvider)
+        {
+            __environmentVariableProvider = environmentVariableProvider;
+        }
+
+        internal static void SetFileSystemProvider(IFileSystemProvider fileSystemProvider)
+        {
+            __fileSystemProvider = fileSystemProvider;
+        }
+
         // private static methods
         internal static BsonDocument CreateClientDocument(string applicationName, LibraryInfo libraryInfo)
         {
@@ -107,13 +122,15 @@ internal static BsonDocument CreateEnvDocument()
                 var timeout = GetTimeoutSec(name);
                 var memoryDb = GetMemoryMb(name);
                 var region = GetRegion(name);
+                var container = GetContainerDocument();
 
                 return new BsonDocument
                 {
                     { "name", name },
                     { "timeout_sec", timeout, timeout.HasValue },
                     { "memory_mb", memoryDb, memoryDb.HasValue },
-                    { "region", region, region != null }
+                    { "region", region, region != null },
+                    { "container", container, container != null }
                 };
             }
             else
@@ -176,6 +193,23 @@ string GetRegion(string name) =>
                     _ => null,
                 };
 
+            BsonDocument GetContainerDocument()
+            {
+                var isExecutionContainerDocker = __fileSystemProvider.File.Exists("/.dockerenv");
+                var isOrchestratorKubernetes = __environmentVariableProvider.GetEnvironmentVariable("KUBERNETES_SERVICE_HOST") != null;
+
+                if (isExecutionContainerDocker || isOrchestratorKubernetes)
+                {
+                    return new()
+                    {
+                        { "runtime", "docker", isExecutionContainerDocker },
+                        { "orchestrator", "kubernetes", isOrchestratorKubernetes }
+                    };
+                }
+
+                return null;
+            }
+
             int? GetIntValue(string environmentVariable) =>
                 int.TryParse(Environment.GetEnvironmentVariable(environmentVariable), out var value) ? value : null;
         }

src/MongoDB.Driver.Core/Core/Misc/FileSystemProvider.cs

@@ -0,0 +1,31 @@
+/* Copyright 2010-present MongoDB Inc.
+ *
+ * Licensed 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.
+ */
+
+namespace MongoDB.Driver.Core.Misc
+{
+    /// <summary>
+    /// Abstractions of the file system.
+    /// </summary>
+    internal interface IFileSystemProvider
+    {
+        IFile File { get; }
+    }
+
+    internal class FileSystemProvider : IFileSystemProvider
+    {
+        public static IFileSystemProvider Instance { get; } = new FileSystemProvider();
+        public IFile File { get; } = new FileWrapper();
+    }
+}

src/MongoDB.Driver.Core/Core/Misc/FileWrapper.cs

@@ -0,0 +1,35 @@
+/* Copyright 2010-present MongoDB Inc.
+ *
+ * Licensed 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.IO;
+
+namespace MongoDB.Driver.Core.Misc
+{
+    /// <summary>
+    /// Abstraction for static methods in <see cref="System.IO.File" />.
+    /// </summary>
+    internal interface IFile
+    {
+        bool Exists(string name);
+    }
+
+    internal sealed class FileWrapper : IFile
+    {
+        public bool Exists(string name)
+        {
+            return File.Exists(name);
+        }
+    }
+}

tests/MongoDB.Driver.Core.Tests/Core/Connections/ClientDocumentHelperTests.cs

@@ -19,7 +19,9 @@
 using MongoDB.Bson;
 using MongoDB.Driver.Core.TestHelpers;
 using MongoDB.Driver.Core.Configuration;
+using MongoDB.Driver.Core.Misc;
 using MongoDB.TestHelpers.XunitExtensions;
+using Moq;
 using Xunit;
 
 namespace MongoDB.Driver.Core.Connections
@@ -132,6 +134,44 @@ public void CreateDriverDocument_with_args_should_return_expected_result(
             result.Should().Be($"{{ name : 'mongo-csharp-driver', version : '{driverVersion}' }}");
         }
 
+        [Theory]
+        [InlineData(true, true, "{ name : 'vercel', container : { \"runtime\" : \"docker\", \"orchestrator\" : \"kubernetes\" }}")]
+        [InlineData(false, true, "{ name : 'vercel', container : { \"orchestrator\" : \"kubernetes\" }}")]
+        [InlineData(true, false, "{ name : 'vercel', container : { \"runtime\" : \"docker\" }}")]
+        [InlineData(false, false, "{ name : 'vercel' }")]
+        public void CreateEnvDocument_should_return_expected_result(bool isDockerToBeDetected, bool isKubernetesToBeDetected, string expected)
+        {
+            var fileSystemProviderMock  = new Mock<IFileSystemProvider>();
+            var environmentVariableProviderMock = new Mock<IEnvironmentVariableProvider>();
+
+            if (isKubernetesToBeDetected)
+            {
+                environmentVariableProviderMock.Setup(p => p.GetEnvironmentVariable("KUBERNETES_SERVICE_HOST")).Returns("dummy");
+            }
+            else
+            {
+                environmentVariableProviderMock.Setup(p => p.GetEnvironmentVariable("KUBERNETES_SERVICE_HOST")).Returns(null as string);
+            }
+
+            if (isDockerToBeDetected)
+            {
+                fileSystemProviderMock.Setup(p => p.File.Exists("/.dockerenv")).Returns(true);
+            }
+            else
+            {
+                fileSystemProviderMock.Setup(p => p.File.Exists("/.dockerenv")).Returns(false);
+
+            }
+
+            ClientDocumentHelper.SetEnvironmentVariableProvider(environmentVariableProviderMock.Object);
+            ClientDocumentHelper.SetFileSystemProvider(fileSystemProviderMock.Object);
+            using (new DisposableEnvironmentVariable("VERCEL"))
+            {
+                var result = ClientDocumentHelper.CreateEnvDocument();
+                result.Should().Be(expected);
+            }
+        }
+
         [Fact]
         public void CreateOSDocument_should_return_expected_result()
         {