[LEDE-DEV] convention on uid/gid for packages

[Eric Luehrsen]

On 15.05.2017 18:02, Val Kulkov wrote:
 > On 15 May 2017 at 11:46, Yousong Zhou <yszhou4tech at gmail.com> wrote:
 >> On 15 May 2017 at 23:29, Val Kulkov <val.kulkov at gmail.com> wrote:
 >>> Yousong, perhaps I was not clear. What I am suggesting is to change
 >>> the auto-allocation to start from 1000 rather than from 100 (1000 is
 >>> just a suggestion, it could be anything else that is high enough), and
 >>> to have a convention to allocate the 1-999 range to the services.
 >>> Then, the allocation of uid/gid for any new package would be subject
 >>> to review and approval by the reviewers. We would have to maintain a
 >>> Wiki page listing all uids and gids that have already been taken,
 >>> FreeBSD-style.
 >>>
 >>> This way, we would only have to reallocate uids and gids for packages
 >>> that are 1000 and higher. The other packages that use uids and gids in
 >>> the 1-999 range would not be affected, other than the packages that
 >>> already have a conflict (icecast and postfix, for example).
 >>>
 >> I guess the the user, group related utility functions are intended for
 >> use by services only.  Adding users and groups for multi-user
 >> interactive is just not the use case for  LEDE (this is only personal
 >> opinion and not in the book).
 >>
 >> The suggestion is to let default_postinst to auto-allocation uid/gid
 >> from 1 or 100, and let useradd/useradd/groupadd/addgroup to start from
 >> whatever high number.
 >>
 >> If we can automate things without separately maintaining a list of any
 >> kind and manual cooperation across groups of people, we should prefer
 >> that
 >>
 >>                  yousong
 > I agree that not depending on the manual cooperation across groups of
 > people would be ideal. However, updating 35+ packages to use the
 > auto-allocation mechanism is not an easy undertaking. Besides, some of
 > the packages might actually rely on particular numeric uid/gid's - we
 > don't know until we run tests with these packages.
 >
 > Here is another suggestion. make menuconfig might collect all USERID:=
 > strings from all packages and produce a list of uids and gids that
 > have been taken so that the auto-allocation mechanism will stay away
 > from these uids/gids. Such lists will likely be fairly compact, taking
 > perhaps less than 500 bytes. This will (1) avoid conflicts between
 > packages, (2) avoid the need to re-do the uid/gid allocation for 35+
 > packages, and (3) not require manual cooperation between groups of
 > people in the future.

I know for Unbound package the hard coded GID/UID doesn't functionally 
matter. Many other packages seem to be the same. You need a non-root 
user to drop down to. You also don't want one common other user or else 
"nobody:nogroup" becomes the new root (in a way). It may not be so 
difficult to get cooperation.

Trouble occurs supporting LEDE vs OpenWrt split. Some people want to SDK 
only a few latest add on packages, but keep their preferred stable base. 
15.01.1 doesn't support install UID/GID assignment. There are other 
divergences. Compatibility across the split generates non-ideal design 
choices. It makes maintaining optional packages more and more difficult. 
Once that matter is closed, this symptom effect may all but solve itself.

- Eric