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Share HFS files between user accounts

This tutorial will walk you through the methods and steps required to share HFS files to other user accounts and access shared files. You can:

  1. Upload files to TWSC COS and share
    • Other users can download files via URLs to their space.
    • Other users can mount COS as a disk to access the files (i.e., a shared folder or a network drive).
  2. Change HFS file permissions.

Please refer to the following steps on how to share files (sharer) and steps on how other users access files (other users):

1. Upload files to TWSC COS and share​

Step 1. Upload files to TWSC COS (sharer)​

Sharers can upload HFS files to COS through S3 client tools or mounting COS as a disk; or Backup/Sync HFS files to COS.

Next steps:

Other users download files via URLs to their space

Step 2. Get file URLs (sharer)​

Get the file URL through third-party software and share the URL with other users.

(The following uses Cyberduck as an operation example)

Step 3. Download files to your space (other users)​

After obtaining the file URL from the sharer, enter the following wgwt command to download the file to your space (TWSC TAIWNIA2 (CLI), VCS, CCS, or other local machines)

& wget <COS file URL>
Other users mount COS as a disk to access the files (i.e., a shared folder or a network drive)

Step 2. Mount COS to TWNIA2 (other users)​

For other users, please refer to this document to mount the sharer's COS as a network disk or shared folder.

Files can be accessed after being mounted to your TWNIA2 (login node) or VCS instances.

2. Change HFS file permissions​

The following steps change the permissions of HFS files/directories through the ACL (Access-control list) enabled on the file system.

The sharer can log in to TWNIA2 (CLI) to enter commands to change file permissions.

caution
  • This is an advanced method, and incorrect settings can lead to data leakage. Considering information security issues, it is recommended that you use the above method to share files through COS.
  • This method only changes file permissions and does not transfer files. Therefore, the files keep occupying the storage space of the sharer after the permission is changed.
  • Please connect to the login node before you changing the file permission.
info

Reference：NCHC

UNIX file permissions​

Use the ls -l command to view the information of the file. The first column indicates the permissions of Owner, Group, Other (not Owner or Group) for the file/directory, for example: -rw-r-- r--, the permission escription is as follows:

Column 1Column 2-4Column 5-7Column 8-10
-：file (d: directory)Owner has r、w、x permissionsGroup has r permissionOther has r permission

Change ACL permissions​

setfacl [-bkRd] [{-m|-x} ACL parameter] target_file_name

Commands​

  • setfacl：set/remove the ACL permissions of a file/directory

Parameters​

  • -m sets following ACL parameters to the files. Cannot be used with -x;
  • -x : deletes following ACL parameters. Cannot be used with -m;
  • -b : removes "all" ACL parameters;
  • -k : removes the "default" ACL parameters. The "default" parameters will be introduced in the following examples;
  • -R : sets ACL recursively, that is, the subdirectories will set the same permission;
  • -d : sets "Default ACL parameters". Only valid for directorys, the new data in the directory will inherit to this default value.

User and Group​

  • -u：change files permissions to a specific user (add his/her system account behind)
  • -g：change files permissions to members of a project （add project number behind）

Permission types​

  • r：read permission
  • w：edit and write permissions
  • x：execute files or enter folders permissions

Operation examples​

1. Set file/directory ACL permission (sharer)​

  • Share the read and write permissions of a file to a specific user (system account). 
setfacl -m u:<UNIX_account>:rw <target_file>
  • Share the read and execute permissions of /home under a system account to a specific project.
setfacl -m g:<project_number>:rx /home/<UNIX_account>
info

The execute permission x parameter is added since opening the folder requires the execute permission.

2. Check the file ACL permissions has been set (sharer)​

  • If the permission is set successfully, a + sign will appear in the permission column. 
ls -ald /path/<target_file or directory>

3. View ACL permissions of file/directory (sharer)​

getfacl <target_file or directory>

You will get the following information of a file/directory:

# file: path/file
# owner: <system account of the file owner>
# group: <project number of the file owner>
user::rwx 
user:<UNUX account>:rwx (permission set to the target user)
group::---
group:<project number>:r-x (permission set to the target project)
mask::r-x
other::---

4. Access files (other users)​

Other users can enter cd command with sharer account to access files or folders. 

cd <UNIX_account_of_sharer>

5. Remove ACL permissions of file/directory (sharer)​

If the files or directories are no longer shared, execute the following command to remove all permissions of the files/directories

setfacl -b <target_file or directory>