Re: git: a28ccb32bf56 - main - machine-id: generate a compact version of the uuid

On 3 Mar 2023, at 9:40, Tijl Coosemans wrote:

> On Wed, 1 Mar 2023 18:18:33 GMT Baptiste Daroussin <bapt@FreeBSD.org> wrote:
>> The branch main has been updated by bapt:
>>
>> URL: https://cgit.FreeBSD.org/src/commit/?id=a28ccb32bf5678fc401f1602865ee9b37ca4c990
>>
>> commit a28ccb32bf5678fc401f1602865ee9b37ca4c990
>> Author:     Baptiste Daroussin <bapt@FreeBSD.org>
>> AuthorDate: 2023-02-28 10:31:06 +0000
>> Commit:     Baptiste Daroussin <bapt@FreeBSD.org>
>> CommitDate: 2023-03-01 18:16:25 +0000
>>
>>     machine-id: generate a compact version of the uuid
>>
>>     dbus and other actually expect an uuid without hyphens
>>
>>     Reported by:    tijl
>>     MFC After:      3 days
>> ---
>>  libexec/rc/rc.d/machine_id | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/libexec/rc/rc.d/machine_id b/libexec/rc/rc.d/machine_id
>> index 7cfd7b2d92f8..8bf3e41d0603 100644
>> --- a/libexec/rc/rc.d/machine_id
>> +++ b/libexec/rc/rc.d/machine_id
>> @@ -23,7 +23,7 @@ machine_id_start()
>>  	if [ ! -f ${machine_id_file} ] ; then
>>  		startmsg -n "Creating ${machine_id_file} "
>>  		t=$(mktemp -t machine-id)
>> -		/bin/uuidgen -r -o $t
>> +		/bin/uuidgen -r -c -o $t
>>  		install -C -o root -g wheel -m ${machine_id_perms} "$t" "${machine_id_file}"
>>  		rm -f "$t"
>>  		startmsg 'done.'
>
> I really think this file should be defined to contain the same UUID as
> /etc/hostid such that there's one and only one UUID per machine.  Having
> two different IDs needlessly complicates things if they end up in logs
> etc.
>
> It also looks like on Linux virtual machines this file contains the
> SMBIOS UUID just like our /etc/hostid.  If /etc/machine-id is supposed
> to be a portable way to obtain that UUID it should be the same as
> /etc/hostid.

I agree.  I had the same reaction when the machine-id was added, but
thought the requirements were different (in particular, the UUID version).
If at all possible, the two should be the same except for hyphens.

> Please have another look at https://reviews.freebsd.org/D38811.  This
> file is supposed to remain constant across updates.  If we get this
> wrong in 13.2, applications may have to deal with the complications for
> a very long time.

This should be resolved for 13.2 if at all possible.

		Mike