feat: Add download all and all namespaces flags (#1917)

# Description

Allow user to download all captures from a specific namespace or from
all namespaces

## Related Issue

#1836

## Checklist

- [x] I have read the [contributing
documentation](https://retina.sh/docs/Contributing/overview).
- [x] I signed and signed-off the commits (`git commit -S -s ...`). See
[this
documentation](https://docs.github.com/en/authentication/managing-commit-signature-verification/about-commit-signature-verification)
on signing commits.
- [ ] I have correctly attributed the author(s) of the code.
- [x] I have tested the changes locally.
- [ ] I have followed the project's style guidelines.
- [x] I have updated the documentation, if necessary.
- [x] I have added tests, if applicable.

## Screenshots (if applicable) or Testing Completed

Please add any relevant screenshots or GIFs to showcase the changes
made.

## Additional Notes

Add any additional notes or context about the pull request here.

---

Please refer to the [CONTRIBUTING.md](../CONTRIBUTING.md) file for more
information on how to contribute to this project.

Author: carlotaarvela

cli/cmd/capture/download.go

@@ -4,7 +4,9 @@
 package capture
 
 import (
+	"archive/tar"
 	"bytes"
+	"compress/gzip"
 	"context"
 	"errors"
 	"fmt"
@@ -20,11 +22,13 @@ import (
 	"github.com/Azure/azure-sdk-for-go/storage"
 	retinacmd "github.com/microsoft/retina/cli/cmd"
 	captureConstants "github.com/microsoft/retina/pkg/capture/constants"
+	captureFile "github.com/microsoft/retina/pkg/capture/file"
 	captureUtils "github.com/microsoft/retina/pkg/capture/utils"
 	captureLabels "github.com/microsoft/retina/pkg/label"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"go.uber.org/zap"
+	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/rand"
@@ -69,6 +73,8 @@ var (
 	ErrNoBlobsFound       = errors.New("no blobs found with prefix")
 	captureName           string
 	outputPath            string
+	downloadAll           bool
+	downloadAllNamespaces bool
 )
 
 var (
@@ -79,6 +85,8 @@ var (
 	ErrEmptyDownloadOutput       = errors.New("download command produced no output")
 	ErrFailedToCreateDownloadPod = errors.New("failed to create download pod")
 	ErrUnsupportedNodeOS         = errors.New("unsupported node operating system")
+	ErrMissingRequiredFlags      = errors.New("either --name, --blob-url, or --all must be specified")
+	ErrAllNamespacesRequiresAll  = errors.New("--all-namespaces flag can only be used with --all flag")
 )
 
 // DownloadCmd holds all OS-specific commands and configurations
@@ -98,6 +106,12 @@ type DownloadService struct {
 	namespace  string
 }
 
+// Key represents a unique capture identifier
+type Key struct {
+	Name      string
+	Namespace string
+}
+
 // NewDownloadService creates a new download service with shared dependencies
 func NewDownloadService(kubeClient kubernetes.Interface, config *rest.Config, namespace string) *DownloadService {
 	return &DownloadService{
@@ -198,6 +212,12 @@ var downloadExample = templates.Examples(i18n.T(`
 		# Download the capture file(s) created using the capture name and define output location
 		kubectl retina capture download --name <capture-name> -o <output-location>
 
+		# Download all available captures
+		kubectl retina capture download --all
+
+		# Download all available captures from all namespaces
+		kubectl retina capture download --all --all-namespaces
+
 		# Download capture file(s) from Blob Storage via Blob URL (Blob URL requires Read/List permissions)
 		kubectl retina capture download --blob-url "<blob-url>"
 `))
@@ -248,49 +268,61 @@ func downloadFromCluster(ctx context.Context, config *rest.Config, namespace str
 
 // DownloadFile downloads a capture file from a specific node
 func (ds *DownloadService) DownloadFile(ctx context.Context, nodeName, hostPath, fileName, captureName string) error {
+	content, err := ds.DownloadFileContent(ctx, nodeName, hostPath, fileName, captureName)
+	if err != nil {
+		return err
+	}
+
+	outputFile := filepath.Join(outputPath, captureName, fileName+".tar.gz")
+	fmt.Printf("Bytes retrieved: %d\n", len(content))
+
+	err = os.WriteFile(outputFile, content, 0o600)
+	if err != nil {
+		return errors.Join(ErrWriteFileToHost, err)
+	}
+
+	fmt.Printf("File written to: %s\n", outputFile)
+	return nil
+}
+
+// DownloadFileContent downloads a capture file from a specific node and returns the content
+func (ds *DownloadService) DownloadFileContent(ctx context.Context, nodeName, hostPath, fileName, captureName string) ([]byte, error) {
 	node, err := ds.kubeClient.CoreV1().Nodes().Get(ctx, nodeName, metav1.GetOptions{})
 	if err != nil {
-		return errors.Join(ErrGetNodeInfo, err)
+		return nil, errors.Join(ErrGetNodeInfo, err)
 	}
 
 	downloadCmd, err := getDownloadCmd(node, hostPath, fileName)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	fmt.Println("File to be downloaded: ", downloadCmd.SrcFilePath)
 	downloadPod, err := ds.createDownloadPod(ctx, nodeName, hostPath, captureName, downloadCmd)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
+	// Ensure cleanup
+	defer func() {
+		cleanupErr := ds.kubeClient.CoreV1().Pods(ds.namespace).Delete(ctx, downloadPod.Name, metav1.DeleteOptions{})
+		if cleanupErr != nil {
+			retinacmd.Logger.Warn("Failed to clean up debug pod", zap.String("name", downloadPod.Name), zap.Error(cleanupErr))
+		}
+	}()
+
 	fileExists, err := ds.verifyFileExists(ctx, downloadPod, downloadCmd)
 	if err != nil || !fileExists {
-		return err
+		return nil, err
 	}
 
 	fmt.Println("Obtaining file...")
 	fileContent, err := ds.executeFileDownload(ctx, downloadPod, downloadCmd)
 	if err != nil {
-		return err
-	}
-
-	outputFile := filepath.Join(outputPath, captureName, fileName+".tar.gz")
-	fmt.Printf("Bytes retrieved: %d\n", len(fileContent))
-
-	err = os.WriteFile(outputFile, fileContent, 0o600)
-	if err != nil {
-		return errors.Join(ErrWriteFileToHost, err)
+		return nil, err
 	}
 
-	fmt.Printf("File written to: %s\n", outputFile)
-
-	// Ensure cleanup
-	err = ds.kubeClient.CoreV1().Pods(ds.namespace).Delete(ctx, downloadPod.Name, metav1.DeleteOptions{})
-	if err != nil {
-		retinacmd.Logger.Warn("Failed to clean up debug pod", zap.String("name", downloadPod.Name), zap.Error(err))
-	}
-	return nil
+	return fileContent, nil
 }
 
 func getCapturePods(ctx context.Context, kubeClient kubernetes.Interface, captureName, namespace string) (*corev1.PodList, error) {
@@ -513,6 +545,195 @@ func downloadFromBlob() error {
 	return nil
 }
 
+func downloadAllCaptures(ctx context.Context, config *rest.Config, namespace string) error {
+	if downloadAllNamespaces {
+		fmt.Println("Downloading all captures from all namespaces...")
+	} else {
+		fmt.Printf("Downloading all captures for namespace %s...\n", namespace)
+	}
+	kubeClient, err := kubernetes.NewForConfig(config)
+	if err != nil {
+		return fmt.Errorf("failed to initialize k8s client: %w", err)
+	}
+
+	// List all capture jobs with the capture app label
+	captureJobSelector := &metav1.LabelSelector{
+		MatchLabels: map[string]string{
+			captureLabels.AppLabel: captureConstants.CaptureAppname,
+		},
+	}
+	labelSelector, err := metav1.LabelSelectorAsSelector(captureJobSelector)
+	if err != nil {
+		return fmt.Errorf("failed to parse label selector: %w", err)
+	}
+
+	var jobList *batchv1.JobList
+	if downloadAllNamespaces {
+		// Search across all namespaces
+		jobList, err = kubeClient.BatchV1().Jobs("").List(ctx, metav1.ListOptions{
+			LabelSelector: labelSelector.String(),
+		})
+		if err != nil {
+			return fmt.Errorf("failed to list capture jobs across all namespaces: %w", err)
+		}
+	} else {
+		// Search in specified namespace only
+		jobList, err = kubeClient.BatchV1().Jobs(namespace).List(ctx, metav1.ListOptions{
+			LabelSelector: labelSelector.String(),
+		})
+		if err != nil {
+			return fmt.Errorf("failed to list capture jobs: %w", err)
+		}
+	}
+
+	if len(jobList.Items) == 0 {
+		if downloadAllNamespaces {
+			fmt.Printf("No captures found across all namespaces\n")
+		} else {
+			fmt.Printf("No captures found in namespace %s\n", namespace)
+		}
+		return nil
+	}
+
+	// Group jobs by capture name and namespace
+	captureToJobs := make(map[Key][]batchv1.Job)
+	for i := range jobList.Items {
+		job := &jobList.Items[i]
+		captureNameFromLabel, ok := job.Labels[captureLabels.CaptureNameLabel]
+		if !ok {
+			continue
+		}
+		key := Key{Name: captureNameFromLabel, Namespace: job.Namespace}
+		captureToJobs[key] = append(captureToJobs[key], *job)
+	}
+
+	fmt.Printf("Found %d capture(s) to download\n", len(captureToJobs))
+
+	// Create the final archive using streaming approach to avoid memory issues
+	timestamp := captureFile.TimeToString(captureFile.Now())
+	finalArchivePath := filepath.Join(outputPath, fmt.Sprintf("all-captures-%s.tar.gz", timestamp))
+
+	fmt.Printf("Creating final archive: %s\n", finalArchivePath)
+	err = createStreamingTarGzArchive(ctx, finalArchivePath, captureToJobs, kubeClient, config)
+	if err != nil {
+		return fmt.Errorf("failed to create final archive: %w", err)
+	}
+
+	fmt.Printf("Successfully created archive: %s\n", finalArchivePath)
+	return nil
+}
+
+// createStreamingTarGzArchive creates a tar.gz archive by streaming files one at a time to avoid memory issues
+func createStreamingTarGzArchive(ctx context.Context, outputPath string, captureToJobs map[Key][]batchv1.Job, kubeClient kubernetes.Interface, config *rest.Config) error {
+	// Create the output file
+	outFile, err := os.Create(outputPath)
+	if err != nil {
+		return fmt.Errorf("failed to create archive file: %w", err)
+	}
+	defer outFile.Close()
+
+	// Create gzip writer
+	gzipWriter := gzip.NewWriter(outFile)
+	defer gzipWriter.Close()
+
+	// Create tar writer
+	tarWriter := tar.NewWriter(gzipWriter)
+	defer tarWriter.Close()
+
+	// We'll create download services per namespace as needed
+	downloadServices := make(map[string]*DownloadService)
+	fileCount := 0
+
+	// Process each capture and stream files directly to archive
+	for captureKey := range captureToJobs {
+		currentCaptureName := captureKey.Name
+		currentNamespace := captureKey.Namespace
+		fmt.Printf("Processing capture: %s in namespace: %s\n", currentCaptureName, currentNamespace)
+
+		// Get or create download service for this namespace
+		downloadService, exists := downloadServices[currentNamespace]
+		if !exists {
+			downloadService = NewDownloadService(kubeClient, config, currentNamespace)
+			downloadServices[currentNamespace] = downloadService
+		}
+
+		// Get pods for this capture and download files
+		pods, podsErr := getCapturePods(ctx, kubeClient, currentCaptureName, currentNamespace)
+		if podsErr != nil {
+			fmt.Printf("Warning: Failed to get pods for capture %s in namespace %s: %v\n", currentCaptureName, currentNamespace, podsErr)
+			continue
+		}
+
+		for i := range pods.Items {
+			pod := pods.Items[i]
+			if pod.Status.Phase != corev1.PodSucceeded {
+				fmt.Printf("Warning: Pod %s is not in Succeeded phase (status: %s), skipping\n", pod.Name, pod.Status.Phase)
+				continue
+			}
+
+			nodeName := pod.Spec.NodeName
+			hostPath, ok := pod.Annotations[captureConstants.CaptureHostPathAnnotationKey]
+			if !ok {
+				fmt.Printf("Warning: Cannot obtain host path from pod annotations for %s\n", pod.Name)
+				continue
+			}
+			fileName, ok := pod.Annotations[captureConstants.CaptureFilenameAnnotationKey]
+			if !ok {
+				fmt.Printf("Warning: Cannot obtain capture file name from pod annotations for %s\n", pod.Name)
+				continue
+			}
+
+			// Download file content (this is still done in memory per file, but not all files at once)
+			content, err := downloadService.DownloadFileContent(ctx, nodeName, hostPath, fileName, currentCaptureName)
+			if err != nil {
+				fmt.Printf("Warning: Failed to download file from pod %s: %v\n", pod.Name, err)
+				continue
+			}
+
+			// Determine archive path based on whether we're using all namespaces
+			var archivePath string
+			if downloadAllNamespaces {
+				// Include namespace in path: namespace/captureName/fileName.tar.gz
+				archivePath = filepath.Join(currentNamespace, currentCaptureName, fileName+".tar.gz")
+			} else {
+				// Original path: captureName/fileName.tar.gz
+				archivePath = filepath.Join(currentCaptureName, fileName+".tar.gz")
+			}
+
+			// Stream file directly to archive
+			header := &tar.Header{
+				Name: archivePath,
+				Mode: 0o600,
+				Size: int64(len(content)),
+			}
+
+			// Write header
+			if err := tarWriter.WriteHeader(header); err != nil {
+				return fmt.Errorf("failed to write header for %s: %w", archivePath, err)
+			}
+
+			// Write content
+			if _, err := tarWriter.Write(content); err != nil {
+				return fmt.Errorf("failed to write content for %s: %w", archivePath, err)
+			}
+
+			fileCount++
+			fmt.Printf("Added %s (%d bytes) to archive\n", archivePath, len(content))
+		}
+	}
+
+	if fileCount == 0 {
+		// Remove the empty archive file
+		outFile.Close()
+		os.Remove(outputPath)
+		fmt.Println("No capture files were successfully downloaded")
+		return nil
+	}
+
+	fmt.Printf("Successfully added %d files to archive\n", fileCount)
+	return nil
+}
+
 func NewDownloadSubCommand() *cobra.Command {
 	downloadCapture := &cobra.Command{
 		Use:     "download",
@@ -534,8 +755,13 @@ func NewDownloadSubCommand() *cobra.Command {
 				captureNamespace = "default"
 			}
 
-			if captureName == "" && blobURL == "" {
-				return errors.New("either --name or --blob-url must be specified")
+			if captureName == "" && blobURL == "" && !downloadAll {
+				return ErrMissingRequiredFlags
+			}
+
+			// Validate all-namespaces flag usage
+			if downloadAllNamespaces && !downloadAll {
+				return ErrAllNamespacesRequiresAll
 			}
 
 			if captureName != "" {
@@ -552,12 +778,21 @@ func NewDownloadSubCommand() *cobra.Command {
 				}
 			}
 
+			if downloadAll {
+				err = downloadAllCaptures(ctx, kubeConfig, captureNamespace)
+				if err != nil {
+					return err
+				}
+			}
+
 			return nil
 		},
 	}
 
 	downloadCapture.Flags().StringVar(&blobURL, "blob-url", "", "Blob URL from which to download")
 	downloadCapture.Flags().StringVar(&captureName, "name", "", "The name of a the capture")
+	downloadCapture.Flags().BoolVar(&downloadAll, "all", false, "Download all available captures for the specified namespace (or all namespaces if --all-namespaces flag is set)")
+	downloadCapture.Flags().BoolVar(&downloadAllNamespaces, "all-namespaces", false, "Download captures from all namespaces (only works with --all flag)")
 	downloadCapture.Flags().StringVarP(&outputPath, "output", "o", DefaultOutputPath, "Path to save the downloaded capture")
 
 	return downloadCapture