Appendix
This appendix contains additional reference material for various topics discussed in this document.
Unix Permissions - Octal Values
The following table can be used as a reference for converting Unix permissions from their binary value to an octal value, which is needed to determine the desired umask setting for your S3 server that uses a local identity provider.
| Permissions | Octal Value | Binary Value | Description |
|---|---|---|---|
|
0 |
000 |
No permissions |
|
1 |
001 |
Execute |
|
2 |
010 |
Write |
|
3 |
011 |
Write and execute |
|
4 |
100 |
Read |
|
5 |
101 |
Read and execute |
|
6 |
110 |
Read and write |
|
7 |
111 |
Read, write, and execute |
To determine what value to use in your umask, you simply determine what you would need to subtract from 7 to reach your desired permission set.
For example, if we want to grant only read permissions for new files/folders (octal value 4 above), we would use a umask value of 3 as 7 - 3 = 4.
Creating Your S3 Umask Value for a Local Identity Provider
A Hammerspace S3 server that uses the local identity provider relies on a umask setting to determine the permissions for new files and folders that were created using the S3 protocol. The default setting is 0002, which can be explained as follows:
-
The first value is 0, which sets the sticky bit to off. The sticky bit is a special file permission flag in Unix-like systems that, when set on a directory, prevents users (other than the owner or root) from deleting or moving files within that directory, even if they have write access.
-
The second value sets the permissions for the file owner; a 0 (7 - 0 = octal permission value of 7) means that the owner will have full access to all files and folders that they create (read/write for files, read/write/execute for folders).
-
The third value sets the permissions for the groups that the file owner is a member of; a 0 (7 - 0 = octal permission value of 7) means that members of those groups will have full access to all files and folders the owner creates (read/write for files, read/write/execute for folders).
-
The fourth value sets the permissions for all other users; a 2 (7 - 2 = octal permission value of 5, the Hammerspace default) means that all other users will have only read/execute permissions for folders and read permissions for files.
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