feat: Log a warning when an unsupported .NET version is detected. (#1852)

Author: nrcventura

src/Agent/NewRelic/Agent/Core/NewRelic.Agent.Core/AgentManager.cs

@@ -268,15 +268,15 @@ private void LogInitialized()
 
                 foreach (var ev in environmentVariables)
                 {
-                    if (!String.IsNullOrEmpty(System.Environment.GetEnvironmentVariable(ev)))
+                    if (!string.IsNullOrEmpty(System.Environment.GetEnvironmentVariable(ev)))
                     {
                         Log.DebugFormat("Environment Variable {0} value: {1}", ev, System.Environment.GetEnvironmentVariable(ev));
                     }
                 }
 
                 foreach (var evs in environmentVariablesSensitive)
                 {
-                    if (!String.IsNullOrEmpty(System.Environment.GetEnvironmentVariable(evs)))
+                    if (!string.IsNullOrEmpty(System.Environment.GetEnvironmentVariable(evs)))
                     {
                         Log.DebugFormat("Environment Variable {0} is configured with a value. Not logging potentially sensitive value", evs);
                     }
@@ -285,6 +285,17 @@ private void LogInitialized()
                 Log.Debug($".NET Runtime Version: {RuntimeInformation.FrameworkDescription}");
             }
 
+#if NETFRAMEWORK
+            if (NewRelic.Core.DotnetVersion.IsUnsupportedDotnetFrameworkVersion(AgentInstallConfiguration.DotnetFrameworkVersion))
+            {
+                Log.WarnFormat("Unsupported installed .NET Framework version {0} dectected. Please use a version of .NET Framework >= 4.6.2.", AgentInstallConfiguration.DotnetFrameworkVersion);
+            }
+#else
+            if (NewRelic.Core.DotnetVersion.IsUnsupportedDotnetCoreVersion(AgentInstallConfiguration.DotnetCoreVersion))
+            {
+                Log.WarnFormat("Unsupported .NET version {0} detected. Please use a version of .NET >= net6.", AgentInstallConfiguration.DotnetCoreVersion);
+            }
+#endif
         }
 
         private void StartServices()

src/NewRelic.Core/DotnetVersion.cs

@@ -5,6 +5,8 @@
 using Microsoft.Win32;
 #endif
 
+using System.Collections.Generic;
+
 namespace NewRelic.Core
 {
     public enum DotnetFrameworkVersion
@@ -122,5 +124,29 @@ public static DotnetCoreVersion GetDotnetCoreVersion()
             return DotnetCoreVersion.Other;
         }
 #endif
+
+        public static bool IsUnsupportedDotnetCoreVersion(DotnetCoreVersion version)
+        {
+            // Newer versions of .net will be flagged as Other until we update our version checking logic.
+            // So we can either check against a supported list, or an unsupported list, but the supported list
+            // is smaller.
+            var supportedDotnetCoreVersions = new List<DotnetCoreVersion> { DotnetCoreVersion.net6, DotnetCoreVersion.net7, DotnetCoreVersion.Other };
+            return !supportedDotnetCoreVersions.Contains(version);
+        }
+
+        public static bool IsUnsupportedDotnetFrameworkVersion(DotnetFrameworkVersion version)
+        {
+            // For .net framework we can maintain a list of unsupported versions to check against
+            // so that newer versions of .net framework will not be listed as an unsupported version.
+            var unsupportedDotnetFrameworkVersions = new List<DotnetFrameworkVersion> {
+                DotnetFrameworkVersion.LessThan45,
+                DotnetFrameworkVersion.net45,
+                DotnetFrameworkVersion.net451,
+                DotnetFrameworkVersion.net452,
+                DotnetFrameworkVersion.net46,
+                DotnetFrameworkVersion.net461
+            };
+            return unsupportedDotnetFrameworkVersions.Contains(version);
+        }
     }
 }

tests/NewRelic.Core.Tests/DotnetVersionTests.cs

@@ -0,0 +1,40 @@
+// Copyright 2020 New Relic, Inc. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+using NUnit.Framework;
+
+namespace NewRelic.Core.Tests
+{
+    [TestFixture]
+    public class DotnetVersionTests
+    {
+        [TestCase(DotnetCoreVersion.LessThan30, ExpectedResult = true)]
+        [TestCase(DotnetCoreVersion.netcoreapp30, ExpectedResult = true)]
+        [TestCase(DotnetCoreVersion.netcoreapp31, ExpectedResult = true)]
+        [TestCase(DotnetCoreVersion.net5, ExpectedResult = true)]
+        [TestCase(DotnetCoreVersion.net6, ExpectedResult = false)]
+        [TestCase(DotnetCoreVersion.net7, ExpectedResult = false)]
+        [TestCase(DotnetCoreVersion.Other, ExpectedResult = false)]
+        public bool IsUnsupportedDotnetCoreVersion(DotnetCoreVersion version)
+        {
+            return DotnetVersion.IsUnsupportedDotnetCoreVersion(version);
+        }
+
+        [TestCase(DotnetFrameworkVersion.LessThan45, ExpectedResult = true)]
+        [TestCase(DotnetFrameworkVersion.net45, ExpectedResult = true)]
+        [TestCase(DotnetFrameworkVersion.net451, ExpectedResult = true)]
+        [TestCase(DotnetFrameworkVersion.net452, ExpectedResult = true)]
+        [TestCase(DotnetFrameworkVersion.net46, ExpectedResult = true)]
+        [TestCase(DotnetFrameworkVersion.net461, ExpectedResult = true)]
+        [TestCase(DotnetFrameworkVersion.net462, ExpectedResult = false)]
+        [TestCase(DotnetFrameworkVersion.net47, ExpectedResult = false)]
+        [TestCase(DotnetFrameworkVersion.net471, ExpectedResult = false)]
+        [TestCase(DotnetFrameworkVersion.net472, ExpectedResult = false)]
+        [TestCase(DotnetFrameworkVersion.net48, ExpectedResult = false)]
+        [TestCase(DotnetFrameworkVersion.net481, ExpectedResult = false)]
+        public bool IsUnsupportedDotnetFrameworkVersion(DotnetFrameworkVersion version)
+        {
+            return DotnetVersion.IsUnsupportedDotnetFrameworkVersion(version);
+        }
+    }
+}