dotnet SIGTERM signal handler registration (#50983)

Author: marcpopMSFT

src/Cli/dotnet/Program.cs

@@ -6,6 +6,7 @@
 using System.CommandLine;
 using System.CommandLine.Parsing;
 using System.Diagnostics;
+using System.Runtime.InteropServices;
 using Microsoft.DotNet.Cli.CommandFactory;
 using Microsoft.DotNet.Cli.CommandFactory.CommandResolution;
 using Microsoft.DotNet.Cli.Commands.Run;
@@ -29,6 +30,10 @@ public class Program
     public static ITelemetry TelemetryClient;
     public static int Main(string[] args)
     {
+        // Register a handler for SIGTERM to allow graceful shutdown of the application on Unix.
+        // See https://github.com/dotnet/docs/issues/46226.
+        using var termSignalRegistration = PosixSignalRegistration.Create(PosixSignal.SIGTERM, _ => Environment.Exit(0));
+
         using AutomaticEncodingRestorer _ = new();
 
         // Setting output encoding is not available on those platforms

test/TestAssets/TestProjects/WatchHotReloadApp/Program.cs

@@ -8,6 +8,7 @@
 using System.Runtime.Versioning;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Runtime.InteropServices;
 
 // <metadata update handler placeholder>
 

test/dotnet-watch.Tests/CommandLine/LaunchSettingsTests.cs

@@ -92,22 +92,15 @@ public async Task RunsWithIterationEnvVariable()
 
             App.Start(testAsset, []);
 
-            await App.AssertStarted();
+            await App.WaitForOutputLineContaining(MessageDescriptor.WaitingForFileChangeBeforeRestarting);
 
-            var source = Path.Combine(testAsset.Path, "Program.cs");
-            var contents = File.ReadAllText(source);
-            const string messagePrefix = "DOTNET_WATCH_ITERATION = ";
+            App.AssertOutputContains("DOTNET_WATCH_ITERATION = 1");
+            App.Process.ClearOutput();
 
-            var value = await App.AssertOutputLineStartsWith(messagePrefix);
-            Assert.Equal(1, int.Parse(value, CultureInfo.InvariantCulture));
+            UpdateSourceFile(Path.Combine(testAsset.Path, "Program.cs"));
 
             await App.WaitForOutputLineContaining(MessageDescriptor.WaitingForFileChangeBeforeRestarting);
-
-            UpdateSourceFile(source);
-            await App.AssertStarted();
-
-            value = await App.AssertOutputLineStartsWith(messagePrefix);
-            Assert.Equal(2, int.Parse(value, CultureInfo.InvariantCulture));
+            App.AssertOutputContains("DOTNET_WATCH_ITERATION = 2");
         }
 
         [Fact]

test/dotnet-watch.Tests/HotReload/ApplyDeltaTests.cs

@@ -429,7 +429,7 @@ public async Task AutoRestartOnRudeEdit(bool nonInteractive)
             await App.WaitForOutputLineContaining(MessageDescriptor.WaitingForChanges);
 
             App.AssertOutputContains(MessageDescriptor.RestartNeededToApplyChanges);
-            App.AssertOutputContains($"⌚ [auto-restart] {programPath}(38,11): error ENC0023: Adding an abstract method or overriding an inherited method requires restarting the application.");
+            App.AssertOutputContains($"⌚ [auto-restart] {programPath}(39,11): error ENC0023: Adding an abstract method or overriding an inherited method requires restarting the application.");
             App.AssertOutputContains($"[WatchHotReloadApp ({ToolsetInfo.CurrentTargetFramework})] Exited");
             App.AssertOutputContains($"[WatchHotReloadApp ({ToolsetInfo.CurrentTargetFramework})] Launched");
             App.Process.ClearOutput();
@@ -459,7 +459,7 @@ public async Task AutoRestartOnRudeEditAfterRestartPrompt()
             await App.AssertOutputLineStartsWith("  ❔ Do you want to restart your app? Yes (y) / No (n) / Always (a) / Never (v)", failure: _ => false);
 
             App.AssertOutputContains(MessageDescriptor.RestartNeededToApplyChanges);
-            App.AssertOutputContains($"❌ {programPath}(38,11): error ENC0023: Adding an abstract method or overriding an inherited method requires restarting the application.");
+            App.AssertOutputContains($"❌ {programPath}(39,11): error ENC0023: Adding an abstract method or overriding an inherited method requires restarting the application.");
             App.Process.ClearOutput();
 
             App.SendKey('a');
@@ -476,7 +476,7 @@ public async Task AutoRestartOnRudeEditAfterRestartPrompt()
             await App.WaitForOutputLineContaining(MessageDescriptor.WaitingForChanges);
 
             App.AssertOutputContains(MessageDescriptor.RestartNeededToApplyChanges);
-            App.AssertOutputContains($"⌚ [auto-restart] {programPath}(38,1): error ENC0033: Deleting method 'F()' requires restarting the application.");
+            App.AssertOutputContains($"⌚ [auto-restart] {programPath}(39,1): error ENC0033: Deleting method 'F()' requires restarting the application.");
             App.AssertOutputContains($"[WatchHotReloadApp ({ToolsetInfo.CurrentTargetFramework})] Exited");
             App.AssertOutputContains($"[WatchHotReloadApp ({ToolsetInfo.CurrentTargetFramework})] Launched");
         }
@@ -514,7 +514,7 @@ public async Task AutoRestartOnNoEffectEdit(bool nonInteractive)
             await App.WaitForOutputLineContaining(MessageDescriptor.WaitingForChanges);
 
             App.AssertOutputContains(MessageDescriptor.RestartNeededToApplyChanges);
-            App.AssertOutputContains($"⌚ [auto-restart] {programPath}(16,19): warning ENC0118: Changing 'top-level code' might not have any effect until the application is restarted.");
+            App.AssertOutputContains($"⌚ [auto-restart] {programPath}(17,19): warning ENC0118: Changing 'top-level code' might not have any effect until the application is restarted.");
             App.AssertOutputContains($"[WatchHotReloadApp ({ToolsetInfo.CurrentTargetFramework})] Exited");
             App.AssertOutputContains($"[WatchHotReloadApp ({ToolsetInfo.CurrentTargetFramework})] Launched");
             App.AssertOutputContains("<Updated>");
@@ -721,6 +721,8 @@ class AppUpdateHandler
         [PlatformSpecificFact(TestPlatforms.Windows)]
         public async Task GracefulTermination_Windows()
         {
+            var tfm = ToolsetInfo.CurrentTargetFramework;
+
             var testAsset = TestAssets.CopyTestAsset("WatchHotReloadApp")
                .WithSource();
 
@@ -739,7 +741,7 @@ public async Task GracefulTermination_Windows()
 
             await App.WaitForOutputLineContaining(MessageDescriptor.WaitingForChanges);
 
-            await App.WaitUntilOutputContains(new Regex(@"dotnet watch 🕵️ \[.*\] Windows Ctrl\+C handling enabled."));
+            await App.WaitUntilOutputContains($"dotnet watch 🕵️ [WatchHotReloadApp ({tfm})] Windows Ctrl+C handling enabled.");
 
             await App.WaitUntilOutputContains("Started");
 
@@ -749,6 +751,37 @@ public async Task GracefulTermination_Windows()
             await App.WaitUntilOutputContains("exited with exit code 0.");
         }
 
+        [PlatformSpecificFact(TestPlatforms.AnyUnix)]
+        public async Task GracefulTermination_Unix()
+        {
+            var tfm = ToolsetInfo.CurrentTargetFramework;
+
+            var testAsset = TestAssets.CopyTestAsset("WatchHotReloadApp")
+               .WithSource();
+
+            var programPath = Path.Combine(testAsset.Path, "Program.cs");
+
+            UpdateSourceFile(programPath, src => src.Replace("// <metadata update handler placeholder>", """
+                using var termSignalRegistration = PosixSignalRegistration.Create(PosixSignal.SIGTERM, _ =>
+                {
+                    Console.WriteLine("SIGTERM detected! Performing cleanup...");
+                });
+                """));
+
+            App.Start(testAsset, [], testFlags: TestFlags.ReadKeyFromStdin);
+
+            await App.WaitForOutputLineContaining(MessageDescriptor.WaitingForChanges);
+
+            await App.WaitUntilOutputContains($"dotnet watch 🕵️ [WatchHotReloadApp ({tfm})] Posix signal handlers registered.");
+
+            await App.WaitUntilOutputContains("Started");
+
+            App.SendControlC();
+
+            await App.WaitForOutputLineContaining("SIGTERM detected! Performing cleanup...");
+            await App.WaitUntilOutputContains("exited with exit code 0.");
+        }
+
         [PlatformSpecificTheory(TestPlatforms.Windows, Skip = "https://github.com/dotnet/sdk/issues/49928")] // https://github.com/dotnet/aspnetcore/issues/63759
         [CombinatorialData]
         public async Task BlazorWasm(bool projectSpecifiesCapabilities)