Add common languages SDKs

.github/workflows/cli-e2e-recording-comment.yml

@@ -113,7 +113,8 @@ jobs:
                a.name.includes('JsReactTemplateTests') ||
                a.name.includes('PythonReactTemplateTests') ||
                a.name.includes('DockerDeploymentTests') ||
-               a.name.includes('TypeScriptPolyglotTests'))
+               a.name.includes('TypeScriptPolyglotTests') ||
+               a.name.includes('PolyglotPythonTests'))
             );
 
             console.log(`Found ${cliE2eArtifacts.length} CLI E2E artifacts`);

Aspire.slnx

@@ -358,6 +358,10 @@
   </Folder>
   <Folder Name="/src/">
     <Project Path="src/Aspire.Hosting.CodeGeneration.TypeScript/Aspire.Hosting.CodeGeneration.TypeScript.csproj" />
+    <Project Path="src/Aspire.Hosting.CodeGeneration.Python/Aspire.Hosting.CodeGeneration.Python.csproj" />
+    <Project Path="src/Aspire.Hosting.CodeGeneration.Go/Aspire.Hosting.CodeGeneration.Go.csproj" />
+    <Project Path="src/Aspire.Hosting.CodeGeneration.Java/Aspire.Hosting.CodeGeneration.Java.csproj" />
+    <Project Path="src/Aspire.Hosting.CodeGeneration.Rust/Aspire.Hosting.CodeGeneration.Rust.csproj" />
     <Project Path="src/Aspire.Hosting.RemoteHost/Aspire.Hosting.RemoteHost.csproj" />
   </Folder>
   <Folder Name="/Testing/">
@@ -447,6 +451,7 @@
     <Project Path="tests/Aspire.Hosting.Redis.Tests/Aspire.Hosting.Redis.Tests.csproj" />
     <Project Path="tests/Aspire.Hosting.RemoteHost.Tests/Aspire.Hosting.RemoteHost.Tests.csproj" />
     <Project Path="tests/Aspire.Hosting.CodeGeneration.TypeScript.Tests/Aspire.Hosting.CodeGeneration.TypeScript.Tests.csproj" />
+    <Project Path="tests/Aspire.Hosting.CodeGeneration.Python.Tests/Aspire.Hosting.CodeGeneration.Python.Tests.csproj" />
     <Project Path="tests/Aspire.Hosting.Seq.Tests/Aspire.Hosting.Seq.Tests.csproj" />
     <Project Path="tests/Aspire.Hosting.SqlServer.Tests/Aspire.Hosting.SqlServer.Tests.csproj" />
     <Project Path="tests/Aspire.Hosting.Testing.Tests/Aspire.Hosting.Testing.Tests.csproj" />

docs/specs/polyglot-apphost.md

@@ -18,7 +18,8 @@ This document describes how the Aspire CLI supports non-.NET app hosts using the
 8. [CLI Integration](#cli-integration)
 9. [Configuration](#configuration)
 10. [Adding New Guest Languages](#adding-new-guest-languages)
-11. [Security](#security)
+11. [Local Development Workflow](#local-development-workflow)
+12. [Security](#security)
 
 ---
 
@@ -1404,6 +1405,112 @@ public sealed class AtsContext
 
 ---
 
+## Local Development Workflow
+
+This section explains how to develop and test custom language SDKs using a local clone of the Aspire repository.
+
+### Prerequisites
+
+1. Clone the Aspire repository:
+
+   ```bash
+   git clone https://github.com/dotnet/aspire.git
+   cd aspire
+   ```
+
+2. Build the repository:
+
+   ```bash
+   ./build.sh   # macOS/Linux
+   ./build.cmd  # Windows
+   ```
+
+### Enabling Polyglot Support
+
+Polyglot support is behind a feature flag that must be enabled before you can use non-.NET languages. Enable it using the `aspire config` command:
+
+```bash
+# Enable polyglot support globally (recommended for SDK development)
+aspire config set features:polyglotSupportEnabled true --global
+
+# Or enable it locally for a specific project
+aspire config set features:polyglotSupportEnabled true
+```
+
+This enables the `--language` option on `aspire init` and `aspire new` commands, and allows the CLI to detect and run non-.NET app hosts.
+
+> **Note:** When running the CLI from source with `dotnet run`, use the full command:
+> ```bash
+> dotnet run --project /path/to/aspire/src/Aspire.Cli/Aspire.Cli.csproj -- config set features:polyglotSupportEnabled true --global
+> ```
+
+### Setting Up Local Development Mode
+
+Set the `ASPIRE_REPO_ROOT` environment variable to point to your local Aspire clone. This enables **development mode**, which:
+
+- Uses **project references** instead of NuGet package references for the AppHost server
+- **Forces code regeneration** on every run (bypasses the package hash cache)
+- Allows you to immediately test changes without publishing packages
+
+```bash
+# macOS/Linux
+export ASPIRE_REPO_ROOT="/path/to/aspire"
+
+# Windows (PowerShell)
+$env:ASPIRE_REPO_ROOT = "D:\aspire"
+
+# Windows (Command Prompt)
+set ASPIRE_REPO_ROOT=D:\aspire
+```
+
+### Scaffolding a New App
+
+Use `dotnet run` to execute the CLI directly from source:
+
+```bash
+# Create a new Python app
+dotnet run --project /path/to/aspire/src/Aspire.Cli/Aspire.Cli.csproj -- init -l python
+
+# Create a new TypeScript app
+dotnet run --project /path/to/aspire/src/Aspire.Cli/Aspire.Cli.csproj -- init -l typescript
+```
+
+The `-l` (or `--language`) flag specifies the target language for scaffolding.
+
+### Running the App
+
+```bash
+# Run the app (standard mode)
+dotnet run --project /path/to/aspire/src/Aspire.Cli/Aspire.Cli.csproj -- run
+
+# Run with debug output
+dotnet run --project /path/to/aspire/src/Aspire.Cli/Aspire.Cli.csproj -- run -d
+```
+
+The `-d` (or `--debug`) flag enables additional diagnostic output, useful when developing and troubleshooting language support.
+
+### Development Workflow Tips
+
+1. **Rapid iteration**: With `ASPIRE_REPO_ROOT` set, the generated SDK in `.modules/` is regenerated on each run, so changes to code generation logic are immediately reflected.
+
+2. **Testing code generators**: Modify your `ICodeGenerator` implementation, then run `aspire run` in a test app—the new generated code will be produced automatically.
+
+3. **Testing language support**: Modify your `ILanguageSupport` implementation, then use `aspire init -l <language>` to test scaffolding or `aspire run` to test detection and execution.
+
+4. **Inspecting generated code**: Check the `.modules/` folder in your test app to see the generated SDK files and verify they match your expectations.
+
+### Quick Reference
+
+| Task | Command |
+|------|---------|
+| Scaffold Python app | `dotnet run --project $ASPIRE_REPO_ROOT/src/Aspire.Cli/Aspire.Cli.csproj -- init -l python` |
+| Scaffold TypeScript app | `dotnet run --project $ASPIRE_REPO_ROOT/src/Aspire.Cli/Aspire.Cli.csproj -- init -l typescript` |
+| Run app | `dotnet run --project $ASPIRE_REPO_ROOT/src/Aspire.Cli/Aspire.Cli.csproj -- run` |
+| Run with debug output | `dotnet run --project $ASPIRE_REPO_ROOT/src/Aspire.Cli/Aspire.Cli.csproj -- run -d` |
+| Add integration | `dotnet run --project $ASPIRE_REPO_ROOT/src/Aspire.Cli/Aspire.Cli.csproj -- add` |
+
+---
+
 ## Security
 
 Both guest and host run locally on the same machine, started by the CLI. This is **not** remote execution.

src/Aspire.Cli/Projects/AppHostServerProject.cs

@@ -618,12 +618,23 @@ private XDocument CreateProductionProjectFile(string sdkVersion, IEnumerable<(st
 
     /// <summary>
     /// Gets the socket path for the AppHost server based on the app path.
+    /// On Windows, returns just the pipe name (named pipes don't use file paths).
+    /// On Unix/macOS, returns the full socket file path.
     /// </summary>
     public string GetSocketPath()
     {
         var pathHash = SHA256.HashData(Encoding.UTF8.GetBytes(_appPath));
         var socketName = Convert.ToHexString(pathHash)[..12].ToLowerInvariant() + ".sock";
 
+        // On Windows, named pipes use just a name, not a file path.
+        // The .NET NamedPipeServerStream and clients will automatically
+        // use the \\.\pipe\ prefix.
+        if (OperatingSystem.IsWindows())
+        {
+            return socketName;
+        }
+
+        // On Unix/macOS, use Unix domain sockets with a file path
         var socketDir = Path.Combine(Path.GetTempPath(), FolderPrefix, "sockets");
         Directory.CreateDirectory(socketDir);
 

src/Aspire.Cli/Projects/DefaultLanguageDiscovery.cs

@@ -32,6 +32,34 @@ internal sealed class DefaultLanguageDiscovery : ILanguageDiscovery
             DetectionPatterns: ["apphost.ts"],
             CodeGenerator: "TypeScript", // Matches ICodeGenerator.Language
             AppHostFileName: "apphost.ts"),
+        new LanguageInfo(
+            LanguageId: new LanguageId(KnownLanguageId.Python),
+            DisplayName: KnownLanguageId.PythonDisplayName,
+            PackageName: "Aspire.Hosting.CodeGeneration.Python",
+            DetectionPatterns: ["apphost.py"],
+            CodeGenerator: "Python",
+            AppHostFileName: "apphost.py"),
+        new LanguageInfo(
+            LanguageId: new LanguageId(KnownLanguageId.Go),
+            DisplayName: KnownLanguageId.GoDisplayName,
+            PackageName: "Aspire.Hosting.CodeGeneration.Go",
+            DetectionPatterns: ["apphost.go"],
+            CodeGenerator: "Go",
+            AppHostFileName: "apphost.go"),
+        new LanguageInfo(
+            LanguageId: new LanguageId(KnownLanguageId.Java),
+            DisplayName: KnownLanguageId.JavaDisplayName,
+            PackageName: "Aspire.Hosting.CodeGeneration.Java",
+            DetectionPatterns: ["AppHost.java"],
+            CodeGenerator: "Java",
+            AppHostFileName: "AppHost.java"),
+        new LanguageInfo(
+            LanguageId: new LanguageId(KnownLanguageId.Rust),
+            DisplayName: KnownLanguageId.RustDisplayName,
+            PackageName: "Aspire.Hosting.CodeGeneration.Rust",
+            DetectionPatterns: ["apphost.rs"],
+            CodeGenerator: "Rust",
+            AppHostFileName: "apphost.rs"),
     ];
 
     /// <inheritdoc />

src/Aspire.Cli/Projects/GuestAppHostProject.cs

@@ -198,12 +198,8 @@ private async Task BuildAndGenerateSdkAsync(DirectoryInfo directory, Cancellatio
             // Step 3: Connect to server
             await using var rpcClient = await AppHostRpcClient.ConnectAsync(socketPath, cancellationToken);
 
-            // Step 4: Install dependencies using GuestRuntime
-            var installResult = await InstallDependenciesAsync(directory, rpcClient, cancellationToken);
-            if (installResult != 0)
-            {
-                return;
-            }
+            // Step 4: Install dependencies using GuestRuntime (best effort - don't block code generation)
+            await InstallDependenciesAsync(directory, rpcClient, cancellationToken);
 
             // Step 5: Generate SDK code via RPC
             await GenerateCodeViaRpcAsync(

src/Aspire.Cli/Projects/KnownLanguageId.cs

@@ -28,4 +28,44 @@ internal static class KnownLanguageId
     /// Short alias for TypeScript that can be used on the command line.
     /// </summary>
     public const string TypeScriptAlias = "typescript";
+
+    /// <summary>
+    /// The language ID for Python AppHost projects.
+    /// </summary>
+    public const string Python = "python";
+
+    /// <summary>
+    /// The display name for Python AppHost projects.
+    /// </summary>
+    public const string PythonDisplayName = "Python";
+
+    /// <summary>
+    /// The language ID for Go AppHost projects.
+    /// </summary>
+    public const string Go = "go";
+
+    /// <summary>
+    /// The display name for Go AppHost projects.
+    /// </summary>
+    public const string GoDisplayName = "Go";
+
+    /// <summary>
+    /// The language ID for Java AppHost projects.
+    /// </summary>
+    public const string Java = "java";
+
+    /// <summary>
+    /// The display name for Java AppHost projects.
+    /// </summary>
+    public const string JavaDisplayName = "Java";
+
+    /// <summary>
+    /// The language ID for Rust AppHost projects.
+    /// </summary>
+    public const string Rust = "rust";
+
+    /// <summary>
+    /// The display name for Rust AppHost projects.
+    /// </summary>
+    public const string RustDisplayName = "Rust";
 }

src/Aspire.Hosting.CodeGeneration.Go/Aspire.Hosting.CodeGeneration.Go.csproj

@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>$(DefaultTargetFramework)</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <RootNamespace>Aspire.Hosting.CodeGeneration.Go</RootNamespace>
+    <!-- Required for Go AppHost support -->
+    <IsPackable>true</IsPackable>
+    <!-- No baseline exists since this package was previously not published -->
+    <DisablePackageBaselineValidation>true</DisablePackageBaselineValidation>
+    <IsAotCompatible>true</IsAotCompatible>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="aspire" />
+    <InternalsVisibleTo Include="Aspire.Hosting.CodeGeneration.Go.Tests" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <EmbeddedResource Include="Resources\transport.go" LogicalName="Aspire.Hosting.CodeGeneration.Go.Resources.transport.go" />
+    <EmbeddedResource Include="Resources\base.go" LogicalName="Aspire.Hosting.CodeGeneration.Go.Resources.base.go" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Aspire.Hosting\Aspire.Hosting.csproj" />
+  </ItemGroup>
+
+</Project>