Support podman

src/Microsoft.Tye.Core/ApplicationBuilder.cs

@@ -9,10 +9,11 @@ namespace Microsoft.Tye
 {
     public sealed class ApplicationBuilder
     {
-        public ApplicationBuilder(FileInfo source, string name)
+        public ApplicationBuilder(FileInfo source, string name, ContainerEngine containerEngine)
         {
             Source = source;
             Name = name;
+            ContainerEngine = containerEngine;
         }
 
         public FileInfo Source { get; set; }
@@ -23,6 +24,8 @@ public ApplicationBuilder(FileInfo source, string name)
 
         public ContainerRegistry? Registry { get; set; }
 
+        public ContainerEngine ContainerEngine { get; set; }
+
         public List<ExtensionConfiguration> Extensions { get; } = new List<ExtensionConfiguration>();
 
         public List<ServiceBuilder> Services { get; } = new List<ServiceBuilder>();

src/Microsoft.Tye.Core/ApplicationFactory.cs

@@ -30,7 +30,7 @@ public static async Task<ApplicationBuilder> CreateAsync(OutputContext output, F
             var rootConfig = ConfigFactory.FromFile(source);
             rootConfig.Validate();
 
-            var root = new ApplicationBuilder(source, rootConfig.Name!)
+            var root = new ApplicationBuilder(source, rootConfig.Name!, new ContainerEngine(rootConfig.ContainerEngineType))
             {
                 Namespace = rootConfig.Namespace
             };

src/Microsoft.Tye.Core/BuildDockerImageStep.cs

@@ -25,7 +25,7 @@ public override async Task ExecuteAsync(OutputContext output, ApplicationBuilder
                 return;
             }
 
-            if (!DockerDetector.Instance.IsUsable(out string? unusableReason))
+            if (!application.ContainerEngine.IsUsable(out string? unusableReason))
             {
                 throw new CommandException($"Cannot generate a docker image for '{service.Name}' because {unusableReason}.");
             }

src/Microsoft.Tye.Core/ConfigModel/ConfigApplication.cs

@@ -28,6 +28,8 @@ public class ConfigApplication
 
         public string? Registry { get; set; }
 
+        public ContainerEngineType? ContainerEngineType { get; set; }
+
         public string? Network { get; set; }
 
         public List<Dictionary<string, object>> Extensions { get; set; } = new List<Dictionary<string, object>>();

src/Microsoft.Tye.Core/ConfigModel/ContainerEngineType.cs

@@ -0,0 +1,12 @@
+// 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.
+
+namespace Microsoft.Tye.ConfigModel
+{
+    public enum ContainerEngineType
+    {
+        Docker,
+        Podman
+    }
+}

src/Microsoft.Tye.Core/ContainerEngine.cs

@@ -0,0 +1,185 @@
+// 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.Net;
+using System.Runtime.InteropServices;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Tye.ConfigModel;
+
+namespace Microsoft.Tye
+{
+    public class ContainerEngine
+    {
+        private static readonly TimeSpan Timeout = TimeSpan.FromSeconds(10);
+
+        // Used by tests:
+        public static ContainerEngine? s_default;
+        public static ContainerEngine Default
+            => (s_default ??= new ContainerEngine(default));
+
+        private bool _isUsable { get; }
+        private string? _unusableReason;
+        private bool _isPodman;
+        private string? _containerHost;
+        private string _aspnetUrlsHost;
+
+        public string AspNetUrlsHost => _aspnetUrlsHost;
+        public string? ContainerHost => _containerHost;
+
+        public Task<int> ExecuteAsync(
+            string args,
+            string? workingDir = null,
+            Action<string>? stdOut = null,
+            Action<string>? stdErr = null,
+            params (string key, string value)[] environmentVariables)
+        => ProcessUtil.ExecuteAsync(CommandName, args, workingDir, stdOut, stdErr, environmentVariables);
+
+        public Task<ProcessResult> RunAsync(
+            string arguments,
+            string? workingDirectory = null,
+            bool throwOnError = true,
+            IDictionary<string, string>? environmentVariables = null,
+            Action<string>? outputDataReceived = null,
+            Action<string>? errorDataReceived = null,
+            Action<int>? onStart = null,
+            Action<int>? onStop = null,
+            CancellationToken cancellationToken = default)
+        => ProcessUtil.RunAsync(CommandName, arguments, workingDirectory, throwOnError, environmentVariables,
+            outputDataReceived, errorDataReceived, onStart, onStop, cancellationToken);
+
+        private string CommandName
+        {
+            get
+            {
+                if (!_isUsable)
+                {
+                    throw new InvalidOperationException($"Container engine is not usable: {_unusableReason}");
+                }
+                return _isPodman ? "podman" : "docker";
+            }
+        }
+
+        public bool IsUsable(out string? unusableReason)
+        {
+            unusableReason = _unusableReason;
+            return _isUsable;
+        }
+
+        public ContainerEngine(ContainerEngineType? containerEngine)
+        {
+            _isUsable = true;
+            _aspnetUrlsHost = "localhost";
+            if ((!containerEngine.HasValue || containerEngine == ContainerEngineType.Podman) &&
+                TryUsePodman(ref _unusableReason, ref _containerHost))
+            {
+                _isPodman = true;
+                return;
+            }
+            if ((!containerEngine.HasValue || containerEngine == ContainerEngineType.Docker) &&
+                TryUseDocker(ref _unusableReason, ref _containerHost, ref _aspnetUrlsHost))
+            {
+                return;
+            }
+            _isUsable = false;
+            _unusableReason = "container engine is not installed.";
+        }
+
+        private static bool TryUsePodman(ref string? unusableReason, ref string? containerHost)
+        {
+            ProcessResult result;
+            try
+            {
+                result = ProcessUtil.RunAsync("podman", "version -f \"{{ .Client.Version }}\"", throwOnError: false, cancellationToken: new CancellationTokenSource(Timeout).Token).Result;
+            }
+            catch
+            {
+                return false;
+            }
+
+            if (result.ExitCode != 0)
+            {
+                unusableReason = $"podman version exited with {result.ExitCode}. Standard error: \"{result.StandardError}\".";
+                return true;
+            }
+
+            if (!Version.TryParse(result.StandardOutput, out Version? version))
+            {
+                unusableReason = $"cannot parse podman version '{result.StandardOutput}'.";
+                return true;
+            }
+            Version minVersion = new Version(3, 1);
+            if (version < minVersion)
+            {
+                unusableReason = $"podman version '{result.StandardOutput}' is less than the required '{minVersion}'.";
+                return true;
+            }
+
+            // Check if podman is configured to allow containers to access host services.
+            bool hostLoopbackEnabled = false;
+            string containersConfPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData, Environment.SpecialFolderOption.DoNotVerify),
+                                                        "containers/containers.conf");
+            string[] containersConf = File.Exists(containersConfPath) ? File.ReadAllLines(containersConfPath) : Array.Empty<string>();
+            // Poor man's TOML parsing.
+            foreach (var line in containersConf)
+            {
+                string trimmed = line.Replace(" ", "");
+                if (trimmed.StartsWith("network_cmd_options=", StringComparison.InvariantCultureIgnoreCase) &&
+                    trimmed.Contains("\"allow_host_loopback=true\""))
+                {
+                    hostLoopbackEnabled = true;
+                    break;
+                }
+            }
+            if (hostLoopbackEnabled)
+            {
+                containerHost = "10.0.2.2";
+            }
+            return true;
+        }
+
+        private static bool TryUseDocker(ref string? unusableReason, ref string? containerHost, ref string aspnetUrlsHost)
+        {
+            ProcessResult result;
+            try
+            {
+                result = ProcessUtil.RunAsync("docker", "version", throwOnError: false, cancellationToken: new CancellationTokenSource(Timeout).Token).Result;
+            }
+            catch
+            {
+                return false;
+            }
+
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
+            {
+                // See: https://github.com/docker/for-linux/issues/264
+                //
+                // host.docker.internal is making it's way into linux docker but doesn't work yet
+                // instead we use the machine IP
+                var addresses = Dns.GetHostAddresses(Dns.GetHostName());
+                containerHost = addresses[0].ToString();
+
+                // We need to bind to all interfaces on linux since the container -> host communication won't work
+                // if we use the IP address to reach out of the host. This works fine on osx and windows
+                // but doesn't work on linux.
+                aspnetUrlsHost = "*";
+            }
+            else
+            {
+                containerHost = "host.docker.internal";
+            }
+
+            if (result.ExitCode != 0)
+            {
+                unusableReason = "docker is not connected.";
+            }
+
+            return true;
+        }
+    }
+}

src/Microsoft.Tye.Core/DockerContainerBuilder.cs

@@ -43,8 +43,7 @@ public static async Task BuildContainerImageFromDockerFileAsync(OutputContext ou
             output.WriteDebugLine("Running 'docker build'.");
             output.WriteCommandLine("docker", $"build \"{contextDirectory}\" -t {container.ImageName}:{container.ImageTag} -f \"{dockerFilePath}\"");
             var capture = output.Capture();
-            var exitCode = await ProcessUtil.ExecuteAsync(
-                $"docker",
+            var exitCode = await application.ContainerEngine.ExecuteAsync(
                 $"build \"{contextDirectory}\" -t {container.ImageName}:{container.ImageTag} -f \"{dockerFilePath}\"",
                 new FileInfo(containerService.DockerFile).DirectoryName,
                 stdOut: capture.StdOut,
@@ -148,8 +147,7 @@ public static async Task BuildContainerImageAsync(OutputContext output, Applicat
                 output.WriteDebugLine("Running 'docker build'.");
                 output.WriteCommandLine("docker", $"build \"{contextDirectory}\" -t {container.ImageName}:{container.ImageTag} -f \"{dockerFilePath}\"");
                 var capture = output.Capture();
-                var exitCode = await ProcessUtil.ExecuteAsync(
-                    $"docker",
+                var exitCode = await application.ContainerEngine.ExecuteAsync(
                     $"build \"{contextDirectory}\" -t {container.ImageName}:{container.ImageTag} -f \"{dockerFilePath}\"",
                     project.ProjectFile.DirectoryName,
                     stdOut: capture.StdOut,