From 70019275cf5bb50f7528e7dfe642fd298cebfb91 Mon Sep 17 00:00:00 2001
From: hime <jaimebz@google.com>
Date: Mon, 23 Dec 2024 22:31:38 +0000
Subject: [PATCH] Remove sh dependency.

---
 cmd/csi_driver/Dockerfile      |  3 +--
 pkg/csi_mounter/csi_mounter.go | 38 +++++++++++-----------------------
 2 files changed, 13 insertions(+), 28 deletions(-)

diff --git a/cmd/csi_driver/Dockerfile b/cmd/csi_driver/Dockerfile
index f28d5220..37a8618c 100644
--- a/cmd/csi_driver/Dockerfile
+++ b/cmd/csi_driver/Dockerfile
@@ -50,8 +50,6 @@ FROM distroless-$TARGETARCH AS output-image
 COPY --from=debian /bin/mount /bin/mount
 COPY --from=debian /bin/umount /bin/umount
 COPY --from=debian /bin/mountpoint /bin/mountpoint
-# We should try to remove these
-COPY --from=debian /bin/sh /bin/sh
 COPY --from=debian /bin/cat /bin/cat
 
 # Copy shared libraries into distroless base.
@@ -73,6 +71,7 @@ SHELL ["/bin/bash", "-c"]
 RUN if ldd /bin/mount | grep "not found"; then echo "!!! Missing deps for mount command !!!" && exit 1; fi
 RUN if ldd /bin/umount | grep "not found"; then echo "!!! Missing deps for umount command !!!" && exit 1; fi
 RUN if ldd /bin/mountpoint | grep "not found"; then echo "!!! Missing deps for mountpoint command !!!" && exit 1; fi
+RUN if ldd /bin/cat | grep "not found"; then echo "!!! Missing deps for cat command !!!" && exit 1; fi
 
 # Final build stage, create the real Docker image with ENTRYPOINT
 FROM output-image
diff --git a/pkg/csi_mounter/csi_mounter.go b/pkg/csi_mounter/csi_mounter.go
index 2a096b0c..4a00660c 100644
--- a/pkg/csi_mounter/csi_mounter.go
+++ b/pkg/csi_mounter/csi_mounter.go
@@ -115,7 +115,7 @@ func (m *Mounter) Mount(source string, target string, fstype string, options []s
 
 	if len(sysfsBDI) != 0 {
 		go func() {
-			// updateReadAheadAndMaxRatio may hang until the file descriptor (fd) is either consumed or canceled.
+			// updateSysfsConfig may hang until the file descriptor (fd) is either consumed or canceled.
 			// It will succeed once dfuse finishes the mount process, or it will fail if dfuse fails
 			// or the mount point is cleaned up due to mounting failures.
 			if err := updateSysfsConfig(target, sysfsBDI); err != nil {
@@ -156,7 +156,7 @@ func (m *Mounter) Mount(source string, target string, fstype string, options []s
 // updateSysfsConfig modifies the kernel page cache settings based on the read_ahead_kb or max_ratio provided in the mountOption,
 // and verifies that the values are successfully updated after the operation completes.
 func updateSysfsConfig(targetMountPath string, sysfsBDI map[string]int64) error {
-	start := time.Now()
+	// Command will hang until mount completes.
 	cmd := exec.Command("mountpoint", "-d", targetMountPath)
 	output, err := cmd.CombinedOutput()
 	if err != nil {
@@ -174,35 +174,21 @@ func updateSysfsConfig(targetMountPath string, sysfsBDI map[string]int64) error
 
 	for key, value := range sysfsBDI {
 		// Update the target value.
-		sysClassEchoCmd := fmt.Sprintf("echo %d > /sys/class/bdi/%s/%s", value, outputStr, key)
-		klog.V(4).Infof("Executing command %s", sysClassEchoCmd)
-		cmd := exec.Command("sh", "-c", sysClassEchoCmd)
-		_, err := cmd.CombinedOutput()
+		sysfsBDIPath := filepath.Join("/sys/class/bdi/", outputStr, key)
+		file, err := os.OpenFile(sysfsBDIPath, os.O_WRONLY|os.O_TRUNC, 0644)
 		if err != nil {
-			return fmt.Errorf("failed to execute command %q: %w", sysClassEchoCmd, err)
+			return fmt.Errorf("failed to open file %q: %w", sysfsBDIPath, err)
 		}
+		defer file.Close()
 
-		// Verify updated value.
-		sysClassCatCmd := fmt.Sprintf("cat /sys/class/bdi/%s/%s", outputStr, key)
-		klog.V(4).Infof("Executing command %s", sysClassCatCmd)
-		cmd = exec.Command("sh", "-c", sysClassCatCmd)
-		op, err := cmd.CombinedOutput()
+		klog.V(4).Infof("Executing command: echo %d %s", value, sysfsBDIPath)
+		cmd := exec.Command("echo", fmt.Sprintf("%d", value))
+		cmd.Stdout = file
+		_, err = cmd.CombinedOutput()
 		if err != nil {
-			return fmt.Errorf("failed to execute command %q: %w", sysClassCatCmd, err)
+			return fmt.Errorf("failed to execute command %q: %w", "echo", err)
 		}
-		klog.V(4).Infof("Output of %q : %s", sysClassCatCmd, op)
-
-		opStr := strings.TrimSpace(string(op))
-		updatedVal, err := strconv.ParseInt(opStr, 10, 0)
-		if err != nil {
-			return fmt.Errorf("invalid %s: %w", key, err)
-		}
-		if updatedVal != value {
-			return fmt.Errorf("mismatch in %s, expected %d, got %d", key, value, updatedVal)
-		}
-
-		currentTime := time.Now()
-		klog.Infof("Successfully set %s to %d for mountPoint %s at '%v' (elapsed time: %v)", key, value, targetMountPath, currentTime, time.Since(start))
+		klog.Infof("Updated %s to %d", sysfsBDIPath, value)
 	}
 
 	return nil