Fix parsing of the ini file to setup sqlalchemylogger

[ger-benjamin]

Hi @sbrunner

We are using this sqlalchemy logger in a project using c2cwsgiutils 1.4. It was working well.
And now, I try to upgrade to c2cwsgiutils 6.0.8, and I can't make it work.

This (draft) PR is open to discussion, and solves already somme issue related to the .ini file, and the way c2cwsgiutils parses it.

The example propose this config for the .ini file.:

[handler_sqlalchemy_logger]
class = c2cwsgiutils.sqlalchemylogger.handlers.SQLAlchemyHandler
args = ({'url':'postgresql://postgres:password@localhost:5432/test','tablename':'test','tableargs': {'schema':'xyz'}},'curl')
level = NOTSET
formatter = generic
propagate = 0

First, the args is wrong I think. I had to add a final comma, otherwise I get an error.

With the current code, the args here will become a stream property, like that:

stream: ext://({'url':'postgresql://postgres:password@localhost:5432/test','tablename':'test','tableargs': {'schema':'xyz'}},'curl')

It's valid for console, or JSON built-in handlers, but te sqlalchemy doesn't expect a stream. It expect a sqlalchem_url, a does_not_contain_expression and a contains_expression parameters.

I can't makes it work with the current python and the args (or kwargs) property. I've tried, even by chnaging the code and passing args instead of stream, but it doesn't work. So, I've adapted the code here to have class_args_ properties.
I think that's also more clear to use class_args_stream instead of args that becomes stream.

One other tweaks I add to do is to change the "handlers" parsing. The current code give returns a String with handlers: console, json. Now, it returns an array: handlers: ['console', 'json'].

With these change, I can starts to use the sqlalchemy parser. But here is still an issue between the emit and the process that write the log into the DB. But this part is magic, I'll need to discuss about this with you.

To do:

• Validate change with you
• Debug sqlalchemy writting => Not needed here: setup sqlalchemy in the project, not via the .ini
• Change class_args_ to class_arg_ => use kwargs instead, and ban args
• Update example's README
• Add breaking change doc => not needed

New to do:

• document pass stream as kwargs
• document init of sqlalchemy logger, by app's main
• Update .ini file

See also: https://docs.python.org/3/library/logging.config.html

[sbrunner]

Why don't use the args instead of introducing custom class_args_* configuration?

[ger-benjamin]

I can't makes it work with the current python and the args (or kwargs) property. I've tried, even by changing the code and passing args instead of stream, but it doesn't work. So, I've adapted the code here to have class_args_ properties.
I think that's also more clear to use class_args_stream instead of args that becomes stream.

To be more clear, logging try to instantiate the c2cwsgiutils.handlers.sqlalchemy handler with only one argument: args (or even stream without my first adaptations), (as a string I guess). And not with sqlalchem_url, does_not_contain_expression and contains_expression arguments.

[ger-benjamin]

Reading the code (and the doc) of logging, It would probably parse the args if it would be used as a fileConfig, but it's interpreted as a dictConfig. And I don't/understand how to do that.
But fileConfig looks more limited and older than dictConfig

[ger-benjamin]

Code updated using kwargs now.
Maybe I've to adapt the readme, to says explicitely how to setup the loggers via the python "main" of the project, and not from the ini.
I'll try first...

[ger-benjamin]

@sbrunner

Everything works now. And everythings' documented here I think.

I don't need a 6.1.0 release anymore for now.

I don't know the issue with the CI here.

[sbrunner]

@ger-benjamin Thanks :-)

To fix the CI error, running pre-commit run black should resolve your issue :-)