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

[Yousong Zhou]

On 22 May 2017 at 19:52, Karl Palsson <karlp at tweak.net.au> wrote:
>
> Yousong Zhou <yszhou4tech at gmail.com> wrote:
>> On 19 May 2017 at 18:44, Karl Palsson <karlp at tweak.net.au>
>> wrote:
>> > Resending to the list properly as planned...
>> >
>> >
>> > I've modified one of my packages (mosquitto) to use the
>> > autoassignment style, as it never cared about the actual uid/gid.
>> >
>> > However, is this really the expected behaviour?
>> >
>> > # cat /etc/passwd
>> > root:x:0:0:root:/root:/bin/ash
>> > daemon:*:1:1:daemon:/var:/bin/false
>> > ftp:*:55:55:ftp:/home/ftp:/bin/false
>> > network:*:101:101:network:/var:/bin/false
>> > nobody:*:65534:65534:nobody:/var:/bin/false
>> > avahi:x:105:105:avahi:/var/run/avahi:/bin/false
>> > dnsmasq:x:453:453:dnsmasq:/var/run/dnsmasq:/bin/false
>> > mosquitto:x:100:102:mosquitto:/var/run/mosquitto:/bin/false <<<
>> > 100:102??
>> >
>> >
>> > I know I don't care, but getting 100 for uid and 102 for gid
>> > seems somewhat unexpected? Is it issuing ids from the same
>> > sequence or something?
>> >
>>
>> no, this is not how group_add_next works. please check the
>> content of /etc/group and see if there might already exist a
>> group of name "network" with id 101.
>>
>
> Correct, "network" was a group too.  But they why did it pick userid 100 for my service?
>

Because uid 100 is not yet taken by the passwd file in the base-files
package...  uid/gid are two different id space.

> Anyway, as I don't _really_ need them to have the same numbers
> for uid/gid, it's just traditional, is it now ok to go and make
> my package use the autoassignment? Or is this something that
> should get tidied up further in the autoassignment code?
>
> Sincerely,
> Karl Palsson
>

As far as I can see, it's safe to use dynamic assignment of uid/gid ;)

Regards,
                yousong