fix cdebug exec for Kubernetes short-lived shells losing the output i…

…ssue

cmd/exec/exec_kubernetes.go

@@ -11,6 +11,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/sirupsen/logrus"
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -34,6 +35,8 @@ import (
 	"github.com/iximiuz/cdebug/pkg/uuid"
 )
 
+// TODO: Handle exit codes - terminate the `cdebug exec` command with the same exit code as the debugger container.
+
 func runDebuggerKubernetes(ctx context.Context, cli cliutil.CLI, opts *options) error {
 	if opts.autoRemove {
 		return fmt.Errorf("--rm flag is not supported for Kubernetes")
@@ -309,6 +312,8 @@ func attachPodDebugger(
 	if status == nil {
 		return fmt.Errorf("error getting debugger container %q status: %+v", debuggerName, err)
 	}
+	logrus.Debugf("Debugger container %q status: %+v", debuggerName, status)
+
 	if status.State.Terminated != nil {
 		dumpDebuggerLogs(ctx, client, ns, podName, debuggerName, cli.OutputStream())
 
@@ -355,18 +360,26 @@ func attachPodDebugger(
 			TTY:       opts.tty,
 		}, scheme.ParameterCodec)
 
-	ctx, cancel := context.WithCancel(ctx)
-	defer cancel()
+	streamingCtx, cancelStreamingCtx := context.WithCancel(ctx)
+	defer cancelStreamingCtx()
+
 	go func() {
-		// Container is not running anymore, stop streaming.
 		_, _ = waitForContainer(ctx, client, ns, podName, debuggerName, false)
-		cli.PrintAux("Debugger container %q is not running...\n", debuggerName)
-		cancel()
-
-		dumpDebuggerLogs(ctx, client, ns, podName, debuggerName, cli.OutputStream())
+		// Debugger container is not running anymore - streaming no longer needed.
+		cancelStreamingCtx()
 	}()
 
-	return stream(ctx, cli, req.URL(), config, opts.tty)
+	if err := stream(streamingCtx, cli, req.URL(), config, opts.tty); err != nil {
+		return fmt.Errorf("error streaming to/from debugger container: %v", err)
+	}
+
+	cli.PrintAux("Debugger container %q terminated...\n", debuggerName)
+
+	if err := dumpDebuggerLogs(ctx, client, ns, podName, debuggerName, cli.OutputStream()); err != nil {
+		return fmt.Errorf("error dumping debugger logs: %v", err)
+	}
+
+	return nil
 }
 
 func stream(
@@ -439,13 +452,12 @@ func dumpDebuggerLogs(
 		if _, err := out.Write(bytes); err != nil {
 			return err
 		}
-
-		if err != nil {
-			if err != io.EOF {
-				return err
-			}
+		if err == io.EOF {
 			return nil
 		}
+		if err != nil {
+			return err
+		}
 	}
 }
 

e2e/exec/docker_test.go

@@ -29,7 +29,7 @@ func TestExecDockerShell(t *testing.T) {
 	defer cleanup()
 
 	res := icmd.RunCmd(
-		icmd.Command("cdebug", "exec", "--rm", "-i", targetID),
+		icmd.Command("cdebug", "exec", "--rm", "-q", "-i", targetID),
 		icmd.WithStdin(strings.NewReader("echo \"hello $((6*7)) world\"\nexit 0\n")),
 	)
 

e2e/exec/kubernetes_test.go

@@ -0,0 +1,74 @@
+package exec
+
+import (
+	"strings"
+	"testing"
+	"text/template"
+
+	"gotest.tools/assert"
+	"gotest.tools/assert/cmp"
+	"gotest.tools/v3/icmd"
+
+	"github.com/iximiuz/cdebug/e2e/internal/fixture"
+	"github.com/iximiuz/cdebug/pkg/uuid"
+)
+
+var (
+	simplePod = template.Must(template.New("simple-pod").Parse(`---
+apiVersion: v1
+kind: Pod
+metadata:
+  name: {{.PodName}}
+  namespace: default
+spec:
+  restartPolicy: Never
+  containers:
+    - image: {{.Image}}
+      imagePullPolicy: IfNotPresent
+      name: app
+`))
+)
+
+func TestExecKubernetesSimple(t *testing.T) {
+	podName := "cdebug-" + strings.ToLower(t.Name()) + "-" + uuid.ShortID()
+	cleanup := fixture.KubectlApply(t, simplePod, map[string]string{
+		"PodName": podName,
+		"Image":   fixture.ImageNginx,
+	})
+	defer cleanup()
+
+	fixture.KubectlWaitFor(t, "pod", podName, "Ready")
+
+	// Exec in the pod
+	res := icmd.RunCmd(
+		icmd.Command("cdebug", "exec", "-q", "pod/"+podName, "busybox"),
+	)
+	res.Assert(t, icmd.Success)
+	assert.Check(t, cmp.Contains(res.Stdout(), "BusyBox v1"))
+
+	// Exec in the pod's container
+	res = icmd.RunCmd(
+		icmd.Command("cdebug", "exec", "-q", "pod/"+podName+"/app", "cat", "/etc/os-release"),
+	)
+	res.Assert(t, icmd.Success)
+	assert.Check(t, cmp.Contains(res.Stdout(), "debian"))
+}
+
+func TestExecKubernetesShell(t *testing.T) {
+	podName := "cdebug-" + strings.ToLower(t.Name()) + "-" + uuid.ShortID()
+	cleanup := fixture.KubectlApply(t, simplePod, map[string]string{
+		"PodName": podName,
+		"Image":   fixture.ImageNginx,
+	})
+	defer cleanup()
+
+	fixture.KubectlWaitFor(t, "pod", podName, "Ready")
+
+	res := icmd.RunCmd(
+		icmd.Command("cdebug", "exec", "-q", "-i", "pod/"+podName+"/app"),
+		icmd.WithStdin(strings.NewReader("echo \"hello $((6*7)) world\"\nexit 0\n")),
+	)
+	res.Assert(t, icmd.Success)
+	assert.Equal(t, res.Stderr(), "")
+	assert.Check(t, cmp.Contains(res.Stdout(), "hello 42 world"))
+}

e2e/internal/fixture/fixture.go

@@ -4,6 +4,7 @@ import (
 	"os/exec"
 	"strings"
 	"testing"
+	"text/template"
 
 	"gotest.tools/icmd"
 
@@ -137,3 +138,37 @@ func NerdctlRunBackground(
 
 	return contID, cleanup
 }
+
+func KubectlApply(
+	t *testing.T,
+	manifestTmpl *template.Template,
+	data interface{},
+) func() {
+	var buf strings.Builder
+	if err := manifestTmpl.Execute(&buf, data); err != nil {
+		t.Fatalf("cannot execute template: %v", err)
+	}
+
+	manifest := buf.String()
+
+	cmd := icmd.Command("kubectl", "apply", "-f", "-")
+	res := icmd.RunCmd(cmd, icmd.WithStdin(strings.NewReader(manifest)))
+	res.Assert(t, icmd.Success)
+
+	return func() {
+		cmd := icmd.Command("kubectl", "delete", "-f", "-")
+		res := icmd.RunCmd(cmd, icmd.WithStdin(strings.NewReader(manifest)))
+		res.Assert(t, icmd.Success)
+	}
+}
+
+func KubectlWaitFor(
+	t *testing.T,
+	kind string,
+	name string,
+	condition string,
+) {
+	cmd := icmd.Command("kubectl", "wait", kind, name, "--for=condition="+condition, "--timeout=60s")
+	res := icmd.RunCmd(cmd)
+	res.Assert(t, icmd.Success)
+}