Purging Hanging Replicas (On Startup and via Command) (#155)

* Purge hanging replicas
* Use dictionary for event serialization
* Subscribing to replica events instead of waiting for arbitrary time in tests
* Only return list of running containers from DockerAssert
* use IDictionary instead of deserializing to ReplicaStatus when removing stale replicas
* Exit logs loop in DockerRunner if container is killed

src/Microsoft.Tye.Core/ProcessUtil.cs

@@ -139,5 +139,15 @@ namespace Microsoft.Tye
 
             return await processLifetimeTask.Task;
         }
+
+        public static void KillProcess(int pid)
+        {
+            try
+            {
+                Process.GetProcessById(pid)?.Kill();
+            }
+            catch (ArgumentException) { }
+            catch (InvalidOperationException) { }
+        }
     }
 }

src/Microsoft.Tye.Hosting/DockerRunner.cs

@@ -15,16 +15,23 @@ namespace Microsoft.Tye.Hosting
 {
     public class DockerRunner : IApplicationProcessor
     {
+        private const string DOCKER_REPLICA_STORE = "docker";
+
         private static readonly TimeSpan DockerStopTimeout = TimeSpan.FromSeconds(30);
         private readonly ILogger _logger;
 
-        public DockerRunner(ILogger logger)
+        private readonly ReplicaRegistry _replicaRegistry;
+
+        public DockerRunner(ILogger logger, ReplicaRegistry replicaRegistry)
         {
             _logger = logger;
+            _replicaRegistry = replicaRegistry;
         }
 
-        public Task StartAsync(Application application)
+        public async Task StartAsync(Application application)
         {
+            await PurgeFromPreviousRun();
+
             var tasks = new Task[application.Services.Count];
             var index = 0;
             foreach (var s in application.Services)
@@ -32,7 +39,7 @@ namespace Microsoft.Tye.Hosting
                 tasks[index++] = s.Value.Description.RunInfo is DockerRunInfo docker ? StartContainerAsync(application, s.Value, docker) : Task.CompletedTask;
             }
 
-            return Task.WhenAll(tasks);
+            await Task.WhenAll(tasks);
         }
 
         public Task StopAsync(Application application)
@@ -157,6 +164,7 @@ namespace Microsoft.Tye.Hosting
 
                 status.DockerCommand = command;
 
+                WriteReplicaToStore(replica);
                 var result = await ProcessUtil.RunAsync(
                     "docker",
                     command,
@@ -199,12 +207,17 @@ namespace Microsoft.Tye.Hosting
 
                 while (!dockerInfo.StoppingTokenSource.Token.IsCancellationRequested)
                 {
-                    await ProcessUtil.RunAsync("docker", $"logs -f {containerId}",
+                    var logsRes = await ProcessUtil.RunAsync("docker", $"logs -f {containerId}",
                         outputDataReceived: data => service.Logs.OnNext($"[{replica}]: {data}"),
                         errorDataReceived: data => service.Logs.OnNext($"[{replica}]: {data}"),
                         throwOnError: false,
                         cancellationToken: dockerInfo.StoppingTokenSource.Token);
 
+                    if (logsRes.ExitCode != 0)
+                    {
+                        break;
+                    }
+
                     if (!dockerInfo.StoppingTokenSource.IsCancellationRequested)
                     {
                         try
@@ -286,6 +299,27 @@ namespace Microsoft.Tye.Hosting
             service.Items[typeof(DockerInformation)] = dockerInfo;
         }
 
+        private async Task PurgeFromPreviousRun()
+        {
+            var dockerReplicas = await _replicaRegistry.GetEvents(DOCKER_REPLICA_STORE);
+            foreach (var replica in dockerReplicas)
+            {
+                var container = replica["container"];
+                await ProcessUtil.RunAsync("docker", $"rm -f {container}", throwOnError: false);
+                _logger.LogInformation("removed contaienr {container} from previous run", container);
+            }
+
+            _replicaRegistry.DeleteStore(DOCKER_REPLICA_STORE);
+        }
+
+        private void WriteReplicaToStore(string container)
+        {
+            _replicaRegistry.WriteReplicaEvent(DOCKER_REPLICA_STORE, new Dictionary<string, string>()
+            {
+                ["container"] = container
+            });
+        }
+
         private static void PrintStdOutAndErr(Service service, string replica, ProcessResult result)
         {
             if (result.ExitCode != 0)

src/Microsoft.Tye.Hosting/ProcessRunner.cs

@@ -17,17 +17,24 @@ namespace Microsoft.Tye.Hosting
 {
     public class ProcessRunner : IApplicationProcessor
     {
+        private const string PROCESS_REPLICA_STORE = "process";
+
         private readonly ILogger _logger;
         private readonly ProcessRunnerOptions _options;
 
-        public ProcessRunner(ILogger logger, ProcessRunnerOptions options)
+        private readonly ReplicaRegistry _replicaRegistry;
+
+        public ProcessRunner(ILogger logger, ReplicaRegistry replicaRegistry, ProcessRunnerOptions options)
         {
             _logger = logger;
+            _replicaRegistry = replicaRegistry;
             _options = options;
         }
 
-        public Task StartAsync(Application application)
+        public async Task StartAsync(Application application)
         {
+            await PurgeFromPreviousRun();
+
             var tasks = new Task[application.Services.Count];
             var index = 0;
             foreach (var s in application.Services)
@@ -41,7 +48,7 @@ namespace Microsoft.Tye.Hosting
                 };
             }
 
-            return Task.WhenAll(tasks);
+            await Task.WhenAll(tasks);
         }
 
         public Task StopAsync(Application application)
@@ -205,6 +212,7 @@ namespace Microsoft.Tye.Hosting
 
                                 status.Pid = pid;
 
+                                WriteReplicaToStore(pid.ToString());
                                 service.ReplicaEvents.OnNext(new ReplicaEvent(ReplicaState.Started, status));
                             },
                             throwOnError: false,
@@ -299,6 +307,29 @@ namespace Microsoft.Tye.Hosting
             return Task.WhenAll(tasks);
         }
 
+        private async Task PurgeFromPreviousRun()
+        {
+            var processReplicas = await _replicaRegistry.GetEvents(PROCESS_REPLICA_STORE);
+            foreach (var replica in processReplicas)
+            {
+                if (int.TryParse(replica["pid"], out var pid))
+                {
+                    ProcessUtil.KillProcess(pid);
+                    _logger.LogInformation("removed process {pid} from previous run", pid);
+                }
+            }
+
+            _replicaRegistry.DeleteStore(PROCESS_REPLICA_STORE);
+        }
+
+        private void WriteReplicaToStore(string pid)
+        {
+            _replicaRegistry.WriteReplicaEvent(PROCESS_REPLICA_STORE, new Dictionary<string, string>()
+            {
+                ["pid"] = pid
+            });
+        }
+
         private static string? GetDotnetRoot()
         {
             var process = Process.GetCurrentProcess();

src/Microsoft.Tye.Hosting/ReplicaRegistry.cs

@@ -0,0 +1,104 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.Json;
+using System.Threading.Tasks;
+using Microsoft.Tye.Hosting.Model;
+using Microsoft.Extensions.Logging;
+using System.Threading;
+using System.Collections.Concurrent;
+
+namespace Microsoft.Tye.Hosting
+{
+    public class ReplicaRegistry : IDisposable
+    {
+        private readonly ILogger _logger;
+        private readonly ConcurrentDictionary<string, SemaphoreSlim> _fileWriteSemaphores;
+        private readonly string _tyeFolderPath;
+
+        public ReplicaRegistry(Model.Application application, ILogger logger)
+        {
+            _logger = logger;
+            _fileWriteSemaphores = new ConcurrentDictionary<string, SemaphoreSlim>();
+            _tyeFolderPath = Path.Join(Path.GetDirectoryName(application.Source), ".tye");
+
+            if (!Directory.Exists(_tyeFolderPath))
+            {
+                Directory.CreateDirectory(_tyeFolderPath);
+            }
+        }
+
+        public bool WriteReplicaEvent(string storeName, IDictionary<string, string> replicaRecord)
+        {
+            var filePath = Path.Join(_tyeFolderPath, GetStoreFile(storeName));
+            var contents = JsonSerializer.Serialize(replicaRecord, new JsonSerializerOptions { WriteIndented = false });
+            var semaphore = GetSempahoreForStore(storeName);
+
+            semaphore.Wait();
+            try
+            {
+                File.AppendAllText(filePath, contents + Environment.NewLine);
+                return true;
+            }
+            catch (DirectoryNotFoundException ex)
+            {
+                _logger.LogWarning(ex, "tye folder is not found. file: {file}", filePath);
+                return false;
+            }
+            finally
+            {
+                semaphore.Release();
+            }
+        }
+
+        public bool DeleteStore(string storeName)
+        {
+            var filePath = Path.Join(_tyeFolderPath, GetStoreFile(storeName));
+
+            try
+            {
+                File.Delete(storeName);
+                return true;
+            }
+            catch (DirectoryNotFoundException ex)
+            {
+                _logger.LogWarning(ex, "tye folder is not found. file: {file}", filePath);
+                return false;
+            }
+        }
+
+        public async ValueTask<IList<IDictionary<string, string>>> GetEvents(string storeName)
+        {
+            var filePath = Path.Join(_tyeFolderPath, GetStoreFile(storeName));
+            
+            if (!File.Exists(filePath))
+            {
+                return Array.Empty<IDictionary<string, string>>();
+            }
+
+            var contents = await File.ReadAllTextAsync(filePath);
+            var events = contents.Split(Environment.NewLine);
+
+            return events.Where(e => !string.IsNullOrEmpty(e.Trim()))
+                .Select(e => JsonSerializer.Deserialize<IDictionary<string, string>>(e))
+                .ToList();
+        }
+
+        private SemaphoreSlim GetSempahoreForStore(string storeName)
+        {
+            return _fileWriteSemaphores.GetOrAdd(storeName, _ => new SemaphoreSlim(1, 1));
+        }
+
+        private string GetStoreFile(string storeName) => $"{storeName}_store";
+
+        public void Dispose()
+        {
+            Directory.Delete(_tyeFolderPath, true);
+        }
+    }
+}

src/Microsoft.Tye.Hosting/TyeHost.cs

@@ -37,6 +37,8 @@ namespace Microsoft.Tye.Hosting
         private readonly string[] _args;
         private readonly string[] _servicesToDebug;
 
+        private ReplicaRegistry? _replicaRegistry;
+
         public TyeHost(Application application, string[] args)
             : this(application, args, new string[0])
         {
@@ -81,7 +83,9 @@ namespace Microsoft.Tye.Hosting
 
             var configuration = app.Configuration;
 
-            _processor = CreateApplicationProcessor(_args, _servicesToDebug, _logger, configuration);
+            _replicaRegistry = new ReplicaRegistry(_application, _logger);
+
+            _processor = CreateApplicationProcessor(_replicaRegistry, _args, _servicesToDebug, _logger, configuration);
 
             await app.StartAsync();
 
@@ -262,7 +266,7 @@ namespace Microsoft.Tye.Hosting
             return false;
         }
 
-        private static AggregateApplicationProcessor CreateApplicationProcessor(string[] args, string[] servicesToDebug, Microsoft.Extensions.Logging.ILogger logger, IConfiguration configuration)
+        private static AggregateApplicationProcessor CreateApplicationProcessor(ReplicaRegistry replicaRegistry, string[] args, string[] servicesToDebug, Microsoft.Extensions.Logging.ILogger logger, IConfiguration configuration)
         {
             var diagnosticOptions = DiagnosticOptions.FromConfiguration(configuration);
             var diagnosticsCollector = new DiagnosticsCollector(logger, diagnosticOptions);
@@ -276,8 +280,8 @@ namespace Microsoft.Tye.Hosting
                 new PortAssigner(logger),
                 new ProxyService(logger),
                 new HttpProxyService(logger),
-                new DockerRunner(logger),
+                new DockerRunner(logger, replicaRegistry),
-                new ProcessRunner(logger, ProcessRunnerOptions.FromArgs(args, servicesToDebug)),
+                new ProcessRunner(logger, replicaRegistry, ProcessRunnerOptions.FromArgs(args, servicesToDebug))
             };
 
             // If the docker command is specified then transform the ProjectRunInfo into DockerRunInfo
@@ -291,6 +295,7 @@ namespace Microsoft.Tye.Hosting
 
         public void Dispose()
         {
+            _replicaRegistry?.Dispose();
             DashboardWebApplication?.Dispose();
         }
     }

test/E2ETest/DockerAssert.cs

@@ -3,6 +3,7 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Generic;
 using System.CommandLine.Invocation;
 using System.Linq;
 using System.Text;
@@ -76,6 +77,31 @@ namespace E2ETest
             }
         }
 
+        public static async Task<string[]> GetRunningContainersIdsAsync(ITestOutputHelper output)
+        {
+            var builder = new StringBuilder();
+
+            output.WriteLine($"> docker ps --format \"{{{{.ID}}}}\"");
+            var exitCode = await Process.ExecuteAsync(
+                "docker",
+                $"ps --format \"{{{{.ID}}}}\"",
+                stdOut: OnOutput,
+                stdErr: OnOutput);
+            if (exitCode != 0)
+            {
+                throw new XunitException($"Running `docker ps` failed." + Environment.NewLine + builder.ToString());
+            }
+
+            var lines = builder.ToString().Split(new[] { '\r', '\n', }, StringSplitOptions.RemoveEmptyEntries);
+            return lines;
+
+            void OnOutput(string text)
+            {
+                builder.AppendLine(text);
+                output.WriteLine(text);
+            }
+        }
+
         private static async Task<string[]> ListDockerImagesIdsAsync(ITestOutputHelper output, string repository)
         {
             // docker images -q '{repository}' returns just the ID of the image (one per line)

test/E2ETest/TestHelpers.cs

@@ -3,16 +3,26 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
+using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
+using System.Linq;
+using System.Reactive.Linq;
 using System.Text;
-using Microsoft.Tye;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Tye.Hosting;
+using Microsoft.Tye.Hosting.Model;
 using Xunit;
+using Xunit.Abstractions;
+using Microsoft.Tye;
 
 namespace E2ETest
 {
     public static class TestHelpers
     {
+        private static readonly TimeSpan WaitForServicesTimeout = TimeSpan.FromSeconds(20);
+
         // https://github.com/dotnet/aspnetcore/blob/5a0526dfd991419d5bce0d8ea525b50df2e37b04/src/Testing/src/TestPathUtilities.cs
         // This can get into a bad pattern for having crazy paths in places. Eventually, especially if we use helix,
         // we may want to avoid relying on sln position.
@@ -64,5 +74,104 @@ namespace E2ETest
             DirectoryCopy.Copy(GetTestProjectDirectory(projectName).FullName, temp.DirectoryPath);
             return temp;
         }
+
+        public static async Task StartHostAndWaitForReplicasToStart(TyeHost host)
+        {
+            var startedTask = new TaskCompletionSource<bool>();
+            var alreadyStarted = 0;
+            var totalReplicas = host.Application.Services.Sum(s => s.Value.Description.Replicas);
+
+            void OnReplicaChange(ReplicaEvent ev)
+            {
+                if (ev.State == ReplicaState.Started)
+                {
+                    Interlocked.Increment(ref alreadyStarted);
+                }
+                else if (ev.State == ReplicaState.Stopped)
+                {
+                    Interlocked.Decrement(ref alreadyStarted);
+                }
+
+                if (alreadyStarted == totalReplicas)
+                {
+                    startedTask.TrySetResult(true);
+                }
+            }
+
+            var servicesStateObserver = host.Application.Services.Select(srv => srv.Value.ReplicaEvents.Subscribe(OnReplicaChange)).ToList();
+            await host.StartAsync();
+
+            using var cancellation = new CancellationTokenSource(WaitForServicesTimeout);
+            try
+            {
+                using (cancellation.Token.Register(() => startedTask.TrySetCanceled()))
+                {
+                    await startedTask.Task;
+                }
+            }
+            catch (TaskCanceledException)
+            {
+                await host.StopAsync();
+                throw;
+            }
+            finally
+            {
+                foreach (var observer in servicesStateObserver)
+                {
+                    observer.Dispose();
+                }
+            }
+        }
+
+        public static async Task PurgeHostAndWaitForGivenReplicasToStop(TyeHost host, string[] replicas, string tyeDir)
+        {
+            static async Task Purge(TyeHost host)
+            {
+                var logger = host.DashboardWebApplication!.Logger;
+                var replicaRegistry = new ReplicaRegistry(host.Application, logger);
+                var processRunner = new ProcessRunner(logger, replicaRegistry, new ProcessRunnerOptions());
+                var dockerRunner = new DockerRunner(logger, replicaRegistry);
+
+                await processRunner.StartAsync(new Application(new FileInfo(host.Application.Source), new Dictionary<string, Service>()));
+                await dockerRunner.StartAsync(new Application(new FileInfo(host.Application.Source), new Dictionary<string, Service>()));
+            }
+
+            var stoppedTask = new TaskCompletionSource<bool>();
+            var remaining = replicas.Length;
+
+            void OnReplicaChange(ReplicaEvent ev)
+            {
+                if (replicas.Contains(ev.Replica.Name) && ev.State == ReplicaState.Stopped)
+                {
+                    Interlocked.Decrement(ref remaining);
+                }
+
+                if (remaining == 0)
+                {
+                    stoppedTask.TrySetResult(true);
+                }
+            }
+
+            var servicesStateObserver = host.Application.Services.Select(srv => srv.Value.ReplicaEvents.Subscribe(OnReplicaChange)).ToList();
+
+            // We purge existing replicas by restarting the host which will initiate the purging process
+            await Purge(host);
+
+            using var cancellation = new CancellationTokenSource(WaitForServicesTimeout);
+            try
+            {
+                using (cancellation.Token.Register(() => stoppedTask.TrySetCanceled()))
+                {
+                    await stoppedTask.Task;
+                }
+            }
+            finally
+            {
+                foreach (var observer in servicesStateObserver)
+                {
+                    observer.Dispose();
+                }
+            }
+        }
     }
 }

test/E2ETest/TyePurgeTests.cs

@@ -0,0 +1,155 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.CommandLine;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Tye;
+using Microsoft.Tye.ConfigModel;
+using Microsoft.Tye.Hosting;
+using Microsoft.Tye.Hosting.Model;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace E2ETest
+{
+    public class TyePurgeTests
+    {
+        private readonly ITestOutputHelper output;
+        private readonly TestOutputLogEventSink sink;
+
+        public TyePurgeTests(ITestOutputHelper output)
+        {
+            this.output = output;
+            sink = new TestOutputLogEventSink(output);
+        }
+
+        [Fact]
+        public async Task FrontendBackendPurgeTest()
+        {
+            var projectDirectory = new DirectoryInfo(Path.Combine(TestHelpers.GetSolutionRootDirectory("tye"), "samples", "frontend-backend"));
+            using var tempDirectory = TempDirectory.Create();
+            DirectoryCopy.Copy(projectDirectory.FullName, tempDirectory.DirectoryPath);
+
+            var projectFile = new FileInfo(Path.Combine(tempDirectory.DirectoryPath, "tye.yaml"));
+            var tyeDir = new DirectoryInfo(Path.Combine(tempDirectory.DirectoryPath, ".tye"));
+            var outputContext = new OutputContext(sink, Verbosity.Debug);
+            var application = await ApplicationFactory.CreateAsync(outputContext, projectFile);
+            var host = new TyeHost(application.ToHostingApplication(), Array.Empty<string>())
+            {
+                Sink = sink,
+            };
+
+            try
+            {
+                await TestHelpers.StartHostAndWaitForReplicasToStart(host);
+                try
+                {
+                    var pids = GetAllAppPids(host.Application);
+
+                    Assert.True(Directory.Exists(tyeDir.FullName));
+                    Assert.Subset(new HashSet<int>(GetAllPids()), new HashSet<int>(pids));
+
+                    await TestHelpers.PurgeHostAndWaitForGivenReplicasToStop(host,
+                        GetAllReplicasNames(host.Application), tyeDir.FullName);
+
+                    var runningPids = new HashSet<int>(GetAllPids());
+                    Assert.True(pids.All(pid => !runningPids.Contains(pid)));
+                }
+                finally
+                {
+                    await host.StopAsync();
+                }
+            }
+            finally
+            {
+                host.Dispose();
+                Assert.False(Directory.Exists(tyeDir.FullName));
+            }
+        }
+
+        [ConditionalFact]
+        [SkipIfDockerNotRunning]
+        public async Task MultiProjectPurgeTest()
+        {
+            var projectDirectory = new DirectoryInfo(Path.Combine(TestHelpers.GetSolutionRootDirectory("tye"), "samples", "multi-project"));
+            using var tempDirectory = TempDirectory.Create();
+            DirectoryCopy.Copy(projectDirectory.FullName, tempDirectory.DirectoryPath);
+
+            var projectFile = new FileInfo(Path.Combine(tempDirectory.DirectoryPath, "tye.yaml"));
+            var tyeDir = new DirectoryInfo(Path.Combine(tempDirectory.DirectoryPath, ".tye"));
+            var outputContext = new OutputContext(sink, Verbosity.Debug);
+            var application = await ApplicationFactory.CreateAsync(outputContext, projectFile);
+            var host = new TyeHost(application.ToHostingApplication(), Array.Empty<string>())
+            {
+                Sink = sink,
+            };
+
+            try
+            {
+                await TestHelpers.StartHostAndWaitForReplicasToStart(host);
+                try
+                {
+                    var pids = GetAllAppPids(host.Application);
+                    var containers = GetAllContainerIds(host.Application);
+
+                    Assert.True(Directory.Exists(tyeDir.FullName));
+                    Assert.Subset(new HashSet<int>(GetAllPids()), new HashSet<int>(pids));
+                    Assert.Subset(new HashSet<string>(await DockerAssert.GetRunningContainersIdsAsync(output)),
+                        new HashSet<string>(containers));
+
+                    await TestHelpers.PurgeHostAndWaitForGivenReplicasToStop(host,
+                        GetAllReplicasNames(host.Application), tyeDir.FullName);
+
+                    var runningPids = new HashSet<int>(GetAllPids());
+                    Assert.True(pids.All(pid => !runningPids.Contains(pid)));
+                    var runningContainers =
+                        new HashSet<string>(await DockerAssert.GetRunningContainersIdsAsync(output));
+                    Assert.True(containers.All(c => !runningContainers.Contains(c)));
+                }
+                finally
+                {
+                    await host.StopAsync();
+                }
+            }
+            finally
+            {
+                host.Dispose();
+                Assert.False(Directory.Exists(tyeDir.FullName));
+            }
+        }
+
+        private string[] GetAllReplicasNames(Microsoft.Tye.Hosting.Model.Application application)
+        {
+            var replicas = application.Services.SelectMany(s => s.Value.Replicas);
+            return replicas.Select(r => r.Value.Name).ToArray();
+        }
+
+        private int[] GetAllAppPids(Microsoft.Tye.Hosting.Model.Application application)
+        {
+            var replicas = application.Services.SelectMany(s => s.Value.Replicas);
+            var ids = replicas.Where(r => r.Value is ProcessStatus).Select(r => ((ProcessStatus)r.Value).Pid ?? -1).ToArray();
+
+            return ids;
+        }
+
+        private string[] GetAllContainerIds(Microsoft.Tye.Hosting.Model.Application application)
+        {
+            var replicas = application.Services.SelectMany(s => s.Value.Replicas);
+            var ids = replicas.Where(r => r.Value is DockerStatus).Select(r => ((DockerStatus)r.Value).ContainerId!).ToArray();
+
+            return ids;
+        }
+
+        private int[] GetAllPids()
+        {
+            return Process.GetProcesses().Select(p => p.Id).ToArray();
+        }
+    }
+}