Support setting GID when creating groups

[marvin]

Feature request add ability to set gid for cloud-init created groups

==== orig description ====
Hi, it would be awesome if the Group and User directives had attributes for setting UID and GIDs.

[Robie Basak (racb)]

Thank you for taking the time to report this bug and helping to make Ubuntu better.

Sounds like this is a wishlist item that needs to go upstream in the first instance.

[Chris Vigelius (chris-vigelius)]

+1 for this, this is literally an one-liner and helpful in many situations:

--- cloudinit/distros/__init__.py 2015-01-26 16:14:06 +0000
+++ cloudinit/distros/__init__.py 2015-03-19 13:51:20 +0000
@@ -324,6 +324,7 @@
             "expiredate": '--expiredate',
             "inactive": '--inactive',
             "selinux_user": '--selinux-user',
+ "uid": '--uid',
         }

         adduser_flags = {

[Uwe Menges (uwe-menges)]

Please note that uid in the cloudinit script needs to be a string with that patch:
  uid: "2342"

This is because the adduser function in __init__.py checks for the options to be a string (for a reason not obvious to me):
  if key in adduser_opts and val and isinstance(val, str):

[Chris Vigelius (chris-vigelius)]

better patch which allows to specify gid for groups, too.

to specify gid, let group key point to a dict with 'gid' (and optional 'members') keys:

groups:
    foo:
       gid = '998'
       members: [u1, u2]
    bar:
       gid = '999'
       ...

[Scott Moser (smoser)]

this looks reasonable.

[Nick Timkovich (nicktimko)]

The ChangeLog seems to claim this (or at least the UID part) was done in 0.7.7 : https://git.launchpad.net/cloud-init/tree/ChangeLog?id=3aa094b6917240e6654993b34a48403cb7e14b02#n35 though it looks like it took until post-0.7.9 to be documented at https://cloudinit.readthedocs.io/en/latest/topics/modules.html?highlight=uid#users-and-groups

Or am I mis-reading things?

[Jon Gjengset (jonhoo)]

I agree with nicktimko — this should be marked as fixed.

[Jon Gjengset (jonhoo)]

Specifically, it was fixed by https://git.launchpad.net/cloud-init/commit/?id=ab04d7a3e0d210805c9db99bf43eb47808809758

[Marco Ceppi (marcoceppi)]

Using the following cloud-init:

ii cloud-init 0.7.9-233-ge586fe35-0ubuntu1~16.04.2

With this script:

```
    #cloud-config
    apt:
    proxy: http://10.16.37.1:8000
    users:
      - name: marco
        sudo: ALL=(ALL) NOPASSWD:ALL
        uid: 9001
```

When the machine is booted this is the user entry:

```
marco:x:1000:1000::/home/marco:
```

It seems uid is not respected still.

[Nick Timkovich (nicktimko)]

IIRC, if the UID in the config file is parsed as an integer, it fails. It looks like that's the case with your demo script, Marco. See an earlier comment: https://bugs.launchpad.net/cloud-init/+bug/1396362/comments/4

Right now I'm struggling with random group IDs being created for multiple users. I specified the UIDs as 1000 and 1010, but I end up with groups to match them either u1000:g1000 and u1010:g1010 or u1000:g1011 and u1010:g1010.

The outstanding bug, imho, is the intolerance of integers in the YAML, and feature request for explicit group IDs.

[manuel (boillodmanuel)]

Hi,
I can see how to set the user uid (https://cloudinit.readthedocs.io/en/latest/topics/modules.html#users-and-groups) but it still seems impossible to set the group gid.

This is an important limitation to me.

My use case is to mount a remote disk (of type NFS) to a virtual machine and I have to set the uid and guid to keep the right file access.

[Chris Read (chris-read)]

Although this bug includes a patch to allow gid to be specified to create_groups, it looks like it was not included.

Any plans on getting this fixed?

[Chad Smith (chad.smith)]

Thanks for the bump on this bug. I can confirm the UID portion of this bug is fixed.
The patch attached is not applicable to today's cloud-init, but I can confirm the ability to gid on added groups isn't possible.

Given the low weight of this bug I'm not sure we are going to work it in the short-term, but if someone were to pick this up, we'd need to adapt the patch, add unittests and extend our JSON schema for users_groups.groups_by_groupname in cloudinit/config/schemas/schema-cloud-config-v1.json to define expected object keys for members and gid.

I've updated the description of the bug to capture today's state.

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/2503