Commit graph

14 commits

Author SHA1 Message Date
Eelco Dolstra 4e84b532ed On macOS with auto-uid-allocation and sandboxing, use the correct gid
macOS doesn't have user namespacing, so the gid of the builder needs
to be nixbld. The logic got "has sandboxing enabled" confused with
"has user namespaces".

Fixes #7529.
2023-01-05 04:58:55 -08:00
Naïm Favier 1f3c0a3c1d
Allow disabling build users by unsetting build-users-group
Unsetting `build-users-group` (without `auto-allocate-uids` enabled)
gives the following error:

```
src/libstore/lock.cc:25: static std::unique_ptr<nix::UserLock> nix::SimpleUserLock::acquire(): Assertion `settings.buildUsersGroup != ""' failed.
```

Fix the logic in `useBuildUsers` and document the default value
for `build-users-group`.
2022-12-14 00:40:30 +01:00
Eelco Dolstra ff12d1c1a1 Check that auto-allocated UIDs don't clash with existing accounts 2022-11-28 20:49:17 +01:00
Eelco Dolstra 3d23b9d032 SimpleUserLock::getSupplementaryGIDs(): Filter out main gid
This avoids having the user's gid in the supplementary group list as
well.
2022-11-22 10:26:17 +01:00
Eelco Dolstra 9d17ce07e8 AutoUserLock: If sandboxing is disabled, use the build users group
We have to use a gid that has write access to the Nix store.
2022-11-21 12:55:49 +01:00
Eelco Dolstra 128910ba23 Separate cgroup support from auto-uid-allocation
The new experimental feature 'cgroups' enables the use of cgroups for
all builds. This allows better containment and enables setting
resource limits and getting some build stats.
2022-11-18 10:39:28 +01:00
Eelco Dolstra 05d258667d Fix build on macOS 2022-11-08 08:00:29 -08:00
Eelco Dolstra 2fde7e0108 Split auto UID allocation from cgroups
Cgroups are now only used for derivations that require the uid-range
range feature. This allows auto UID allocation even on systems that
don't have cgroups (like macOS).

Also, make things work on modern systems that use cgroups v2 (where
there is a single hierarchy and no "systemd" controller).
2022-11-08 16:03:42 +01:00
Eelco Dolstra b95faccf03 Merge remote-tracking branch 'origin/master' into auto-uid-allocation 2022-11-03 17:43:40 +01:00
Bernardo Meurer 931930feb1 fix(libstore/lock): support users that belong to more than 10 groups
The manpage for `getgrouplist` says:

> If the number of groups of which user is a member is less than or
> equal to *ngroups, then the value *ngroups is returned.
>
> If the user is a member of more than *ngroups groups, then
> getgrouplist() returns -1.  In this case, the value returned in
> *ngroups can be used to resize the buffer passed to a further
> call getgrouplist().

In our original code, however, we allocated a list of size `10` and, if
`getgrouplist` returned `-1` threw an exception. In practice, this
caused the code to fail for any user belonging to more than 10 groups.

While unusual for single-user systems, large companies commonly have a
huge number of POSIX groups users belong to, causing this issue to crop
up and make multi-user Nix unusable in such settings.

The fix is relatively simple, when `getgrouplist` fails, it stores the
real number of GIDs in `ngroups`, so we must resize our list and retry.
Only then, if it errors once more, we can raise an exception.

This should be backported to, at least, 2.9.x.
2022-06-08 13:45:41 -04:00
John Ericson dc92b01885 Merge remote-tracking branch 'upstream/master' into auto-uid-allocation 2022-02-28 23:54:20 +00:00
John Ericson 801e6d96d8 Merge commit 'd334fd48824b41b57e267cd2926fa9619b7718e3' into auto-uid-allocation 2020-10-17 19:31:06 +00:00
John Ericson bcb67e1ed8 Trim lock.cc 2020-10-11 16:44:19 +00:00
John Ericson e0be04129b Rename to hand-hold git (lock.cc) 2020-10-11 16:44:14 +00:00
Renamed from src/libstore/build.cc (Browse further)