OPC # 0002: Improvements to Client provisioning workflows

Co-authored-by: Copilot <copilot@github.com>

ControlPlane.Api/Endpoints/ImageBuildEndpoints.cs

@@ -1,5 +1,7 @@
-using ControlPlane.Api.Services;
+using System.Diagnostics;
 using System.Text.Json;
+using System.Text.RegularExpressions;
+using ControlPlane.Api.Services;
 
 namespace ControlPlane.Api.Endpoints;
 
@@ -11,8 +13,13 @@ public static class ImageBuildEndpoints
     {
         var group = app.MapGroup("/api/image").WithTags("Image");
 
-        group.MapGet("/status", GetStatus);
-        group.MapPost("/build", TriggerBuild);
+        group.MapGet("/status",  GetStatus);
+        group.MapPost("/build",  TriggerBuild);
+
+        // Post-provisioning verification helpers
+        group.MapGet ("/verify/extra-hosts/{containerName}", GetExtraHosts);
+        group.MapPost("/verify/dns-test",                    DnsTest);
+        group.MapGet ("/artifact/{subdomain}",               GetArtifact);
 
         return app;
     }
@@ -72,4 +79,118 @@ public static class ImageBuildEndpoints
         await ctx.Response.WriteAsync("data: {\"done\":true}\n\n", ct);
         await ctx.Response.Body.FlushAsync(ct);
     }
+
+    // ── Post-provisioning verification endpoints ──────────────────────────────
+
+    private static readonly Regex SafeContainerName = new(@"^[a-zA-Z0-9_.\-]+$", RegexOptions.Compiled);
+
+    /// <summary>
+    /// Returns the ExtraHosts list for a running tenant container.
+    /// e.g. GET /api/image/verify/extra-hosts/fdev-app-clarity-01000001
+    /// </summary>
+    private static async Task<IResult> GetExtraHosts(string containerName)
+    {
+        if (!SafeContainerName.IsMatch(containerName))
+            return Results.BadRequest(new { error = "Invalid container name." });
+
+        var (code, output) = await DockerRunAsync($"inspect --format {{{{json .HostConfig.ExtraHosts}}}} {containerName}");
+        if (code != 0 || string.IsNullOrWhiteSpace(output))
+            return Results.NotFound(new { error = $"Container '{containerName}' not found or not running.", detail = output });
+
+        try
+        {
+            var hosts = JsonDocument.Parse(output.Trim()).RootElement;
+            return Results.Ok(new { containerName, extraHosts = hosts });
+        }
+        catch
+        {
+            return Results.Ok(new { containerName, extraHosts = (object?)null, raw = output.Trim() });
+        }
+    }
+
+    /// <summary>
+    /// Runs <c>curl</c> from inside the container to verify *.clarity.test DNS resolves through nginx.
+    /// POST /api/image/verify/dns-test  body: { container, url }
+    /// </summary>
+    private static async Task<IResult> DnsTest(DnsTestRequest body)
+    {
+        if (!SafeContainerName.IsMatch(body.Container))
+            return Results.BadRequest(new { error = "Invalid container name." });
+
+        // Only allow http/https URLs — prevents command injection via url field
+        if (!body.Url.StartsWith("http://", StringComparison.OrdinalIgnoreCase) &&
+            !body.Url.StartsWith("https://", StringComparison.OrdinalIgnoreCase))
+            return Results.BadRequest(new { error = "URL must start with http:// or https://." });
+
+        var psi = new ProcessStartInfo("docker",
+            $"exec {body.Container} curl -sf --max-time 10 --write-out \"\\nHTTP %{{http_code}}\" {body.Url}")
+        {
+            RedirectStandardOutput = true,
+            RedirectStandardError  = true,
+            UseShellExecute        = false,
+            CreateNoWindow         = true,
+        };
+
+        using var proc = Process.Start(psi);
+        if (proc is null) return Results.Problem("Failed to start docker process.");
+
+        var stdout = await proc.StandardOutput.ReadToEndAsync();
+        var stderr = await proc.StandardError.ReadToEndAsync();
+        await proc.WaitForExitAsync();
+
+        return Results.Ok(new
+        {
+            success  = proc.ExitCode == 0,
+            exitCode = proc.ExitCode,
+            output   = stdout.Trim(),
+            error    = stderr.Trim(),
+        });
+    }
+
+    /// <summary>
+    /// Reads the generated docker-compose.yml from ClientAssets/{subdomain}/.
+    /// GET /api/image/artifact/{subdomain}
+    /// </summary>
+    private static async Task<IResult> GetArtifact(string subdomain, IConfiguration config)
+    {
+        // Restrict subdomain to safe characters — prevents path traversal
+        if (!SafeContainerName.IsMatch(subdomain))
+            return Results.BadRequest(new { error = "Invalid subdomain." });
+
+        var root = config["ClientAssets__Folder"] ?? config["ClientAssets:Folder"]
+                   ?? Path.GetFullPath(Path.Combine(AppContext.BaseDirectory, "..", "ClientAssets"));
+
+        // Use Path.GetFileName to ensure no directory traversal
+        var safeSubdomain  = Path.GetFileName(subdomain);
+        var composePath    = Path.GetFullPath(Path.Combine(root, safeSubdomain, "docker-compose.yml"));
+
+        // Verify the final path is still inside the ClientAssets root
+        if (!composePath.StartsWith(Path.GetFullPath(root), StringComparison.OrdinalIgnoreCase))
+            return Results.BadRequest(new { error = "Invalid subdomain path." });
+
+        if (!File.Exists(composePath))
+            return Results.NotFound(new { error = $"No compose artifact found for '{subdomain}'." });
+
+        var content = await File.ReadAllTextAsync(composePath);
+        return Results.Ok(new { subdomain, path = composePath, content });
+    }
+
+    private static async Task<(int code, string? output)> DockerRunAsync(string args)
+    {
+        var psi = new ProcessStartInfo("docker", args)
+        {
+            RedirectStandardOutput = true,
+            RedirectStandardError  = true,
+            UseShellExecute        = false,
+            CreateNoWindow         = true,
+        };
+        using var proc = Process.Start(psi);
+        if (proc is null) return (-1, null);
+        var output = await proc.StandardOutput.ReadToEndAsync();
+        var err    = await proc.StandardError.ReadToEndAsync();
+        await proc.WaitForExitAsync();
+        return (proc.ExitCode, string.IsNullOrWhiteSpace(output) ? err : output);
+    }
+
+    private record DnsTestRequest(string Container, string Url);
 }