longhorn/enhancements/20230116-smb-cifs-backup-store-support.md
Derek Su b1ed0589b2 Add LEP for SMB/CIFS Backup Store Support
Longhorn 3599

Signed-off-by: Derek Su <derek.su@suse.com>
2023-02-09 13:19:15 +08:00

2.3 KiB

SMB/CIFS Backup Store Support

Summary

Longhorn supports SMB/CIFS share as a backup storage.

https://github.com/longhorn/longhorn/issues/3599

Motivation

Goals

  • Support SMB/CIFS share as a backup storage.

Proposal

  • Introduce SMB/CIFS client for supporting SMB/CIFS as a backup storage.

User Stories

Longhorn already supports NFSv4 and S3 servers as backup storage. However, certain users may encounter compatibility issues with their backup servers, particularly those running on Windows, as the protocols for NFSv4 and S3 are not always supported. To address this issue, the enhancement will enhance support for backup storage options with a focus on the commonly used SMB/CIFS protocol, which is compatible with both Linux and Windows-based servers.

User Experience In Details

  • Check each Longhorn node's kernel supports the CIFS filesystem by
    cat /boot/config-`uname -r` | grep CONFIG_CIFS
    
  • Install the CIFS filesystem user-space tools cifs-utils on each Longhorn node
  • Users can configure a SMB/CIFS share as a backup storage
    • Set Backup Target. The path to a SMB/CIFS share is like

      cifs://${IP address}/${share name}
      
    • Set Backup Target Credential Secret

      • Create a secret and deploy it

        apiVersion: v1
        kind: Secret
        metadata:
          name: cifs-secret
          namespace: longhorn-system
        type: Opaque
        data:
          CIFS_USERNAME: ${CIFS_USERNAME}
          CIFS_PASSWORD: ${CIFS_PASSWORD}
        
      • Set the setting Backup Target Credential Secret to cifs-secret

Design

Implementation Overview

  • longhorn-manager
    • Introduce the fields CIFS_USERNAME and CIFS_PASSWORD in credentials. The two fields are passed to engine and replica processes for volume backup and restore operations.
  • backupstore
    • Implement SMB/CIFS register/unregister and mount/unmount functions

Test Plan

Integration Tests

  1. Set a SMB/CIFS share as backup storage.
  2. Back up volumes to the backup storage and the operation should succeed.
  3. Restore backups and the operation should succeed.