Chore: Refactor

* Copy dqlite file from pod using PodExecutor and cat command
* Remove dedicated function to copy file from pod

Author: mrajagopal

pkg/data_collector/data_collector.go

@@ -266,68 +266,3 @@ func (c *DataCollector) AllNamespacesExist() bool {
 
 	return allExist
 }
-
-// CopyFileFromPod copies a file from a pod's container to the local filesystem.
-func (c *DataCollector) CopyFileFromPod(namespace, pod, container, srcPath, destPath string, ctx context.Context) error {
-	cmd := []string{"tar", "cf", "-", "-C", filepath.Dir(srcPath), filepath.Base(srcPath)}
-	req := c.K8sCoreClientSet.CoreV1().RESTClient().Post().
-		Namespace(namespace).
-		Resource("pods").
-		Name(pod).
-		SubResource("exec").
-		VersionedParams(&corev1.PodExecOptions{
-			Container: container,
-			Command:   cmd,
-			Stdin:     false,
-			Stdout:    true,
-			Stderr:    true,
-			TTY:       false,
-		}, scheme.ParameterCodec)
-
-	exec, err := remotecommand.NewSPDYExecutor(c.K8sRestConfig, "POST", req.URL())
-	if err != nil {
-		return err
-	}
-
-	// Stream the data from the Pod
-	var stdout, stderr bytes.Buffer
-	err = exec.StreamWithContext(ctx, remotecommand.StreamOptions{
-		Stdout: &stdout,
-		Stderr: &stderr,
-	})
-	if err != nil {
-		return err
-	}
-
-	// Create a local file to save the output
-	localFile, err := os.Create(destPath)
-	if err != nil {
-		// return fmt.Errorf("failed to create local file: %w", err)
-		return err
-	}
-	defer localFile.Close()
-
-	// Untar the stream and write the content to the local file
-	tarReader := tar.NewReader(&stdout)
-	for {
-		header, err := tarReader.Next()
-
-		if err == io.EOF {
-			break // End of tar archive
-		}
-		if err != nil {
-			return err
-		}
-
-		// Ensure the tar file matches the expected file path
-		if header.Name == filepath.Base(srcPath) {
-			_, err = io.Copy(localFile, tarReader)
-			if err != nil {
-				return fmt.Errorf("failed to write to local file: %w", err)
-			}
-			break
-		}
-	}
-
-	return nil
-}

pkg/jobs/nim_job_list.go

@@ -20,6 +20,7 @@ package jobs
 
 import (
 	"context"
+	"os"
 	"path/filepath"
 	"strings"
 	"time"
@@ -239,15 +240,23 @@ func NIMJobList() []Job {
 
 										// Copy the dumped file from the pod to the host
 										destPathFilename := filepath.Join(dc.BaseDir, "exec", namespace, pod.Name+"__dqlite-dump-"+filepath.Base(config.outputFile))
-										if err := dc.CopyFileFromPod(namespace, pod.Name, config.containerName, config.outputFile, destPathFilename, ctx); err != nil {
+										copyCmd := []string{"cat", config.outputFile}
+										fileContent, err := dc.PodExecutor(namespace, pod.Name, config.containerName, copyCmd, ctx)
+										if err != nil {
 											jobResult.Error = err
 											dc.Logger.Printf("\tFailed to copy dumped file %s from pod %s in namespace %s to %s: %v\n", config.outputFile, pod.Name, namespace, destPathFilename, err)
 										} else {
-											dc.Logger.Printf("\tSuccessfully copied dumped file %s from pod %s in namespace %s to %s\n", config.outputFile, pod.Name, namespace, destPathFilename)
+											err = os.WriteFile(destPathFilename, fileContent, 0644)
+											if err != nil {
+												jobResult.Error = err
+												dc.Logger.Printf("\tFailed to write file to %s: %v\n", destPathFilename, err)
+											} else {
+												dc.Logger.Printf("\tSuccessfully copied dumped file %s from pod %s in namespace %s to %s\n", config.outputFile, pod.Name, namespace, destPathFilename)
+											}
 										}
 
 										// Remove/delete the dumped file from the pod
-										_, err := dc.PodExecutor(namespace, pod.Name, config.containerName, []string{"rm", "-f", config.outputFile}, ctx)
+										_, err = dc.PodExecutor(namespace, pod.Name, config.containerName, []string{"rm", "-f", config.outputFile}, ctx)
 										if err != nil {
 											jobResult.Error = err
 											dc.Logger.Printf("\tFailed to remove dumped file %s from pod %s in namespace %s: %v\n", config.outputFile, pod.Name, namespace, err)