Use the JSON formatter

To use the JSON formatter, simply associate it to any handler such as the StreamHandler here.

import logmatic
import logging

logger = logging.getLogger()

handler = logging.StreamHandler()
handler.setFormatter(logmatic.JsonFormatter(extra={"hostname":socket.gethostname()}))

logger.addHandler(handler)
logger.setLevel(logging.INFO)

Once this setup is done, any child logger will use this configuration (eg logging.getlogger("my_logger")). As you can see, you can associate any extra information to the base formatter such as the hostname here or any environment variable you’ll need depending of your usage.

test_logger = logging.getLogger("test")
test_logger.info("classic message", extra={"special": "value", "run": 12})

Returns the following format:

{
  "asctime": "2016-02-16T09:51:31Z",
  "name": "test", "processName": "MainProcess",
  "filename": "write_in_console.py",
  "funcName": "<module>",
  "levelname": "INFO",
  "lineno": 20,
  "module": "write_in_console",
  "threadName": "MainThread",
  "message": "classic message",
  "special": "value",
  "run": 12,
  "timestamp": "2016-02-16T09:51:31Z",
  "hostname": "<your_hostname>"
}

Let’s take some time here to understand what we have:

• The default format is “%(asctime) %(name) %(processName) %(filename) %(funcName) %(levelname) %(lineno) %(module) %(threadName) %(message)”. So that’s why all these attributes are present on all the log events. If you need less, you can change the format when defining the formatter: logmatic.JsonFormatter(fmt="",...)

• The hostname attribute here is added all the time as it was defined on the root logger.

• The special and run attributes were added specifically to this log event.

Good to know, an traceback from an exception is totally wrapped into the JSON event. That’s suppress the handling of multiline formatting:

{
  ...
  "exc_info": "Traceback (most recent call last):\n  File \"test/write_in_console.py\", line 24, in exception_test\n    raise Exception('test')\nException: test",
  ...
}

Stream log straight to Logmatic.io

The LogmaticHandler can be coupled to the JsonFormatter as follow:

import logmatic
import logging

logger = logging.getLogger()

handler = logmatic.LogmaticHandler("<your_api_key>")
handler.setFormatter(logmatic.JsonFormatter(extra={"hostname":socket.gethostname()}))

logger.addHandler(handler)
logger.setLevel(logging.INFO)

Don’t forget to replace by the one provided on your Logmatic.io’s platform.

With this configuration, any log coming from your Python’s application will be sent to your platform and will fulfill the same format as described in the previous section.

Please contact us if you want anything more to be added in this toolset!