[systemd-devel] python - reading the journal

Steven Hiscocks steven-systemd at hiscocks.me.uk
Tue Feb 19 13:02:56 PST 2013

On 19/02/13 07:05, David Strauss wrote:
> On Mon, Feb 18, 2013 at 11:28 AM, Steven Hiscocks
> <steven-systemd at hiscocks.me.uk> wrote:
>> Sounds good. I suppose `log_level` should become `add_loglevel_matches` for
>> consistency. (or actually `add_priority_matches`?)
> "Log level" is the Pythonic language; please continue using it. The
> journal itself may even move to it because "priority" is
> counter-intuitive.
>> I was missing the default value of None in `this_machine`. It's supposed to
>> be used: "myjournal.this_machine()" (or "myjournal.add_machine_match()" with
>> above changes). Alternatively, the default None could be removed , and
>> constants set `CURRENT_MACHINE=id128.get_machine()`, etc., which then should
>> be used when calling the method?
> That sounds even better. Presumably, id128.get_machine() is not too
> heavy to call once each time the logging code gets imported?
I can imagine the overhead is negligible. Looking at the id128 code, it 
appears to just read "/etc/machine-id" and 
"/proc/sys/kernel/random/boot_id". (You could even get away with doing 
this in python ;) )
> The ultimate would be CURRENT_MACHINE=<something-constant> and a
> function that lazy-loads id128.get_machine() on the first request. It
> may be a premature optimization for performance, but it's nice to be
> able to import a Python module without worrying about it throwing an
> exception initializing its constants.
I put in place holder for now for the constants using the id128 
functions. Might be something to change if people have issues...
>> I'll add this to the documentation, but I think `get_next` should stay, as
>> it compliments `get_previous` and use of the `skip` value.
> Makes sense.
>> Sure. I'll put in `UnicodeDecodeError`. I'm undecided on whether the call of
>> `self.converters[key](value)` exception handling should be limited to
>> `KeyError`? This would mean that the whole log entry would fail to return if
>> one of the converters failed.
> Even a set of explicit exception classes is okay. Something that's a
> complete surprise will still bubble up.
I've left the current code with catch all fall back to Unicode. It 
doesn't seem right that a whole log entry fails to return, just because 
one field is skewif.
> --

I've pushed a few more commits.

Steven Hiscocks

More information about the systemd-devel mailing list