[Engine-devel] Small suggestions for engine-log-collector

[Keith Robertson]

On 03/12/2014 07:05 AM, Vojtech Szocs wrote:
>
>
> ----- Original Message -----
>> From: "Keith Robertson" <kroberts at redhat.com>
>> To: "Vojtech Szocs" <vszocs at redhat.com>
>> Cc: "engine-devel" <engine-devel at ovirt.org>, "Einav Cohen" <ecohen at redhat.com>, "Sandro Bonazzola"
>> <sbonazzo at redhat.com>
>> Sent: Tuesday, March 11, 2014 7:13:08 PM
>> Subject: Re: Small suggestions for engine-log-collector
>>
>>
>>
>> ----- Original Message -----
>>> From: "Vojtech Szocs" <vszocs at redhat.com>
>>> To: "engine-devel" <engine-devel at ovirt.org>
>>> Cc: "Keith Robertson" <kroberts at redhat.com>, "Einav Cohen"
>>> <ecohen at redhat.com>
>>> Sent: Tuesday, March 11, 2014 1:57:11 PM
>>> Subject: Small suggestions for engine-log-collector
>>>
>>> Hi guys,
>>>
>>> based on my testing during last week's oVirt 3.4 RC test day [1],
>>> I have a couple of small suggestions for engine-log-collector:
>>>
>>> 1, in /etc/ovirt-engine/logcollector.conf - I think there's typo:
>>>
>>>        #key-file=/etc/pki/engine/keys/engine_id_rsa
>>>
>>>     should be:
>>>
>>>        #key-file=/etc/pki/ovirt-engine/keys/engine_id_rsa
>>>
>>
>> ACK
>
> http://gerrit.ovirt.org/#/c/25653/
>
>>
>>
>>> 2, to force password-based ssh auth, one has to do this:
>>>
>>
>> In the normal scenario, the the ovirt user's public key should be installed
>> into each hypervisor.  Unless something has changed as a part of the
>> hypervisor registration process this should be something that we can depend
>> upon.
>
> My host was F19 VM added to oVirt Engine via WebAdmin GUI. I thought that
> host deploy script should do the public key registration, though.
>

I'm pretty sure that public key registration used to be part of the 
deploy script.  If this is no longer the case it is a fairly major 
supportability issue.

>>
>> Clearly, there are edge cases where you need to collect logs from a
>> hypervisor that isn't properly registered with the RHEV-M.  Was this your
>> situation and how common do you think this scenario is?
>
> It was either a misconfiguration on my part or that I skipped some step with
> regard to public key registration.
>

Understand.

The reason why we bias the LC towards public key auth and fall back to 
PW auth is that the LC needs to make multiple calls[1] to each 
Hypervisor and, if you're not using public key auth it is definitely a 
sub-optimal usage experience.  Multiply [1] times the N number of 
hyper-visors and the user's annoyance factor will surely reach a boiling 
point. ;)

[1]
- 1 ssh call to launch sos
- 1 sftp call to get the report and remove it from /tmp





>>
>>>        engine-log-collector -k ""
>>>
>>
>> Yes, you are nulling out the default value which causes the LC to prompt you
>> for a PW.  Perhaps we should document this as opposed to supplying a
>> specific option?  Sandro?
>
> Well, the doc text says "If a identity file is not supplied..." which I
> understood as not supplying option value (i.e. "") at all, but this was
> just my understanding.
>

Your understanding is correct and you forced the tool not to find the 
default identity file with a clever null argument.

There's nothing wrong with this usage per-se and maybe we should either 
document it or provide an explicit option to force PW auth.

>>
>>>     because running this:
>>>
>>>        engine-log-collector -k
>>>
>>>     returns error message:
>>>
>>>        error: -k option requires an argument
>>>
>>>     however, help for -k option mentions *supplying* the argument:
>>>
>>>        If a identity file is not supplied the program will prompt for a
>>>        password.
>>>
>>>     so either the help text should mention empty string,
>>>     or -k option should allow missing argument (this was
>>>     my initial understanding according to help text)
>>>
>>> Since these are just small things, I'm wondering if I should
>>> create RFE or if Keith/others can say if they are relevant.
>>>
>>> Thanks,
>>> Vojtech
>>>
>>> [1] http://etherpad.ovirt.org/p/3.4-testday-3
>>>
>>


-- 
Keith Robertson
Supervisor, Software Engineering
Red Hat Subscription Engineering