[pve-devel] [PATCH v2 common] REST environment: default to root at pam in forked workers if no user was specified

[Thomas Lamprecht]

On 15.03.22 12:21, Oguz Bektas wrote:
> On Tue, Mar 15, 2022 at 09:57:34AM +0100, Thomas Lamprecht wrote:
>> On 15.03.22 08:31, Fabian Ebner wrote:
>>> Am 14.03.22 um 14:50 schrieb Oguz Bektas:
>>>> first call $rpcenv->get_user() if user was 'undef'. if that doesn't
>>>> return then we set it to root at pam.
>>
>> this is just the "whats done" description, that's not really interesting for
>> such a short patch, as it can be read from the code change directly without
>> much effort. A sentence about why (original code reason, change reason to the
>> new behavior) and impact (what are the call sites that could be affected)
>> would be more helpful.
> 
> those were all in the v1 patch for pve-container (which had the only call

but there no reference whatsoever to that, so someone checking pve-common's
history and stumbling over this commit is not aware at all of any such info.

So please either copy (for common) relevant info here or at least reference
the repo and commit id of the container patch for context, thx.

>>>> +
>>>> +    if (!defined($user)) {
>>>> +	warn 'internal error: Worker user was not specified, defaulting to "root at pam"!';
>>
>> missing newline at the ends means spamming the log more with internal perl module
>> file/line location and I don't really get the warning in the first place, either
>> it's OK to fallback or not.
>>
>> The REST-env should have a valid user for most (all?) API/CLI-handler derived use
>> cases, as only the public API calls have no user set but there we don't use fork_worker
>> at all.
>>
>> So, I'd examine possible call sites that won't have a user passed nor available via
>> get_user(), and dependening from if they even exist I'd
>>
>> * check if we could set a sensible user-id, if possible, there already
>> * make this either a no-warn or just drop the if-block and avoid passing the $noerr
>>   to $self->get_user(), making this a usage error. The latter would be cleaner, but
>>   has some theoretic breakage potential. As call-site evaluation should be done in any
>>   case, as neither breakage nor defaulting to root at pam is something that should be done
>>   "blindly" (I mean, root fallback was probably intended originally, just avoided due
>>    to the realm typo, but still).
> 
> see the v1 patch for pve-container. i didn't find any other call sites, the
> warning was in case we forgot any other call sites somewhere.
> 

that's exactly why I'd always like to have some context, allows to safe some
typing/research time ^^

> defaulting to 'root at pam' in this case actually has no effect but it's
> only in the logging for tasks.

if this is only ever used for logging (I did not get that from the commit message) then
warning makes not much sense, set $noerr and just fallback, i.e. something like

# note: below is for logging purpose only:
$user = $self->get_user(1) // 'root at pam' if !defined($user);

> 
> i talked to dietmar about this off-list before sending the v1, since
> this bit of code was originally imported from the svn repositories way
> back, and he told me that it was intended for the log.

k