[K3s] Emit LF line endings in generated helm/kubectl scripts (fixes Windows-only busybox syntax error)

src/CommunityToolkit.Aspire.Hosting.K3s/K3sBuilderExtensions.Helm.cs

@@ -224,22 +224,22 @@ internal static string BuildHelmScript(HelmReleaseResource release)
         // can appear in the bind-mount before the k8s hostname resolves in the helm
         // container. Using `helm list` (which calls the k8s API) verifies both the
         // file and the network path before proceeding.
-        sb.AppendLine("_k3s_wait=0");
-        sb.AppendLine($"until [ -f {K3sFileHelpers.ContainerKubeconfigPath} ] && helm list --kubeconfig {K3sFileHelpers.ContainerKubeconfigPath} > /dev/null 2>&1; do");
-        sb.AppendLine("  _k3s_wait=$((_k3s_wait + 5))");
-        sb.AppendLine("  if [ \"$_k3s_wait\" -ge 600 ]; then");
-        sb.AppendLine("    echo 'Timed out waiting for k3s cluster to be ready after 10 minutes' >&2");
-        sb.AppendLine("    exit 1");
-        sb.AppendLine("  fi");
-        sb.AppendLine("  echo 'Waiting for k3s cluster to be ready and reachable...'");
-        sb.AppendLine("  sleep 5");
-        sb.AppendLine("done");
+        sb.AppendShellLine("_k3s_wait=0");
+        sb.AppendShellLine($"until [ -f {K3sFileHelpers.ContainerKubeconfigPath} ] && helm list --kubeconfig {K3sFileHelpers.ContainerKubeconfigPath} > /dev/null 2>&1; do");
+        sb.AppendShellLine("  _k3s_wait=$((_k3s_wait + 5))");
+        sb.AppendShellLine("  if [ \"$_k3s_wait\" -ge 600 ]; then");
+        sb.AppendShellLine("    echo 'Timed out waiting for k3s cluster to be ready after 10 minutes' >&2");
+        sb.AppendShellLine("    exit 1");
+        sb.AppendShellLine("  fi");
+        sb.AppendShellLine("  echo 'Waiting for k3s cluster to be ready and reachable...'");
+        sb.AppendShellLine("  sleep 5");
+        sb.AppendShellLine("done");
 
         if (release.RepoUrl is not null)
         {
             var alias = $"aspire-k3s-{release.ReleaseName}";
-            sb.AppendLine($"helm repo add --force-update {ShellEscape(alias)} {ShellEscape(release.RepoUrl)}");
-            sb.AppendLine($"helm repo update {ShellEscape(alias)}");
+            sb.AppendShellLine($"helm repo add --force-update {ShellEscape(alias)} {ShellEscape(release.RepoUrl)}");
+            sb.AppendShellLine($"helm repo update {ShellEscape(alias)}");
         }
 
         var chartRef = release.RepoUrl is not null

src/CommunityToolkit.Aspire.Hosting.K3s/K3sBuilderExtensions.Manifest.cs

@@ -166,39 +166,39 @@ internal static string BuildManifestScript()
         // DCP sets up container network aliases asynchronously, so the kubeconfig file
         // can appear in the bind-mount before the k8s hostname resolves in the kubectl
         // container. Using `kubectl cluster-info` verifies both the file and the network.
-        sb.AppendLine("_k3s_wait=0");
-        sb.AppendLine($"until [ -f {K3sFileHelpers.ContainerKubeconfigPath} ] && kubectl cluster-info --kubeconfig {K3sFileHelpers.ContainerKubeconfigPath} > /dev/null 2>&1; do");
-        sb.AppendLine("  _k3s_wait=$((_k3s_wait + 5))");
-        sb.AppendLine("  if [ \"$_k3s_wait\" -ge 600 ]; then");
-        sb.AppendLine("    echo 'Timed out waiting for k3s cluster to be ready after 10 minutes' >&2");
-        sb.AppendLine("    exit 1");
-        sb.AppendLine("  fi");
-        sb.AppendLine("  echo 'Waiting for k3s cluster to be ready and reachable...'");
-        sb.AppendLine("  sleep 5");
-        sb.AppendLine("done");
+        sb.AppendShellLine("_k3s_wait=0");
+        sb.AppendShellLine($"until [ -f {K3sFileHelpers.ContainerKubeconfigPath} ] && kubectl cluster-info --kubeconfig {K3sFileHelpers.ContainerKubeconfigPath} > /dev/null 2>&1; do");
+        sb.AppendShellLine("  _k3s_wait=$((_k3s_wait + 5))");
+        sb.AppendShellLine("  if [ \"$_k3s_wait\" -ge 600 ]; then");
+        sb.AppendShellLine("    echo 'Timed out waiting for k3s cluster to be ready after 10 minutes' >&2");
+        sb.AppendShellLine("    exit 1");
+        sb.AppendShellLine("  fi");
+        sb.AppendShellLine("  echo 'Waiting for k3s cluster to be ready and reachable...'");
+        sb.AppendShellLine("  sleep 5");
+        sb.AppendShellLine("done");
 
         // Auto-detect kustomize: if a kustomization file is present, use -k.
         // Otherwise use -f with server-side apply.
         // Capture output so we can extract any CRD names that were applied.
-        sb.AppendLine("if [ -f /k8s-manifests/kustomization.yaml ] || [ -f /k8s-manifests/kustomization.yml ]; then");
-        sb.AppendLine("  echo 'Detected kustomization — using kubectl apply -k'");
-        sb.AppendLine("  APPLIED=$(kubectl apply -k /k8s-manifests --server-side --field-manager=aspire-k3s --force-conflicts)");
-        sb.AppendLine("else");
-        sb.AppendLine("  APPLIED=$(kubectl apply -f /k8s-manifests --server-side --field-manager=aspire-k3s --force-conflicts)");
-        sb.AppendLine("fi");
-        sb.AppendLine("echo \"$APPLIED\"");
+        sb.AppendShellLine("if [ -f /k8s-manifests/kustomization.yaml ] || [ -f /k8s-manifests/kustomization.yml ]; then");
+        sb.AppendShellLine("  echo 'Detected kustomization — using kubectl apply -k'");
+        sb.AppendShellLine("  APPLIED=$(kubectl apply -k /k8s-manifests --server-side --field-manager=aspire-k3s --force-conflicts)");
+        sb.AppendShellLine("else");
+        sb.AppendShellLine("  APPLIED=$(kubectl apply -f /k8s-manifests --server-side --field-manager=aspire-k3s --force-conflicts)");
+        sb.AppendShellLine("fi");
+        sb.AppendShellLine("echo \"$APPLIED\"");
 
         // Parse the apply output for CRD names — kubectl apply prints one line per resource
         // in the form "<kind>/<name> <verb>", e.g.:
         //   customresourcedefinition.apiextensions.k8s.io/widgets.example.com created
         // Only lines starting with "customresourcedefinition." belong to this apply.
         // This avoids touching pre-existing or concurrently installed cluster CRDs and
         // prevents busybox xargs from returning exit code 123 when grep finds no match.
-        sb.AppendLine("CRD_NAMES=$(echo \"$APPLIED\" | grep '^customresourcedefinition\\.' | awk '{print $1}')");
-        sb.AppendLine("if [ -n \"$CRD_NAMES\" ]; then");
-        sb.AppendLine("  # shellcheck disable=SC2086");
-        sb.AppendLine("  kubectl wait --for=condition=Established $CRD_NAMES --timeout=300s");
-        sb.AppendLine("fi");
+        sb.AppendShellLine("CRD_NAMES=$(echo \"$APPLIED\" | grep '^customresourcedefinition\\.' | awk '{print $1}')");
+        sb.AppendShellLine("if [ -n \"$CRD_NAMES\" ]; then");
+        sb.AppendShellLine("  # shellcheck disable=SC2086");
+        sb.AppendShellLine("  kubectl wait --for=condition=Established $CRD_NAMES --timeout=300s");
+        sb.AppendShellLine("fi");
 
         return sb.ToString();
     }

src/CommunityToolkit.Aspire.Hosting.K3s/K3sShellScript.cs

@@ -0,0 +1,32 @@
+using System.Text;
+
+namespace CommunityToolkit.Aspire.Hosting;
+
+/// <summary>
+/// Helpers for composing the POSIX shell scripts that are generated on the host and
+/// injected into the Linux helper containers (<c>alpine/helm</c>, <c>alpine/kubectl</c>).
+/// </summary>
+internal static class K3sShellScript
+{
+    /// <summary>
+    /// Appends <paramref name="line"/> followed by a single LF (<c>\n</c>).
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// <b>Never use <see cref="StringBuilder.AppendLine(string)"/> for generated shell
+    /// scripts.</b> It appends <see cref="Environment.NewLine"/>, which is CRLF on Windows.
+    /// The scripts are executed by busybox <c>ash</c> inside a Linux container, and busybox
+    /// does not strip the trailing CR: a line such as <c>if [ ... ]; then</c> is tokenized
+    /// as <c>then\r</c>, which is not the <c>then</c> keyword. The <c>if</c> is therefore
+    /// never closed and the script aborts at EOF with
+    /// <c>syntax error: unexpected end of file (expecting "then")</c>.
+    /// </para>
+    /// <para>
+    /// The bug is invisible on Linux and macOS build agents (where
+    /// <see cref="Environment.NewLine"/> is already LF), so it only ever surfaces for
+    /// developers running the AppHost on Windows.
+    /// </para>
+    /// </remarks>
+    internal static StringBuilder AppendShellLine(this StringBuilder builder, string line) =>
+        builder.Append(line).Append('\n');
+}

tests/CommunityToolkit.Aspire.Hosting.K3s.Tests/HelmReleaseResourceTests.cs

@@ -224,6 +224,20 @@ public void BuildHelmScriptIncludesUpgradeInstall()
         Assert.Contains("'argo-cd'", script);
     }
 
+    [Fact]
+    public void BuildHelmScriptUsesLfLineEndingsOnly()
+    {
+        // Regression: StringBuilder.AppendLine emits Environment.NewLine (CRLF on Windows).
+        // busybox ash in alpine/helm does not strip the CR, so `then\r` is not the `then`
+        // keyword and the script dies with
+        // "syntax error: unexpected end of file (expecting \"then\")".
+        var script = K3sHelmBuilderExtensions.BuildHelmScript(
+            MakeRelease("argocd", "argo-cd", "https://argoproj.github.io/argo-helm", "7.8.0", "argocd",
+                new Dictionary<string, string> { ["server.service.type"] = "NodePort" }));
+
+        Assert.DoesNotContain('\r', script);
+    }
+
     [Fact]
     public void BuildHelmScriptIncludesWaitAndNamespace()
     {

tests/CommunityToolkit.Aspire.Hosting.K3s.Tests/K8sManifestResourceTests.cs

@@ -195,6 +195,18 @@ public void BuildManifestScriptIncludesKubectlApply()
         Assert.Contains("--server-side", script);
     }
 
+    [Fact]
+    public void BuildManifestScriptUsesLfLineEndingsOnly()
+    {
+        // Regression: StringBuilder.AppendLine emits Environment.NewLine (CRLF on Windows).
+        // busybox ash in alpine/kubectl does not strip the CR, so `then\r` is not the
+        // `then` keyword and the script dies with
+        // "syntax error: unexpected end of file (expecting \"then\")".
+        var script = K3sManifestBuilderExtensions.BuildManifestScript();
+
+        Assert.DoesNotContain('\r', script);
+    }
+
     [Fact]
     public void BuildManifestScriptAutoDetectsKustomize()
     {