Logging

The easiest way to inspect bitcoinkernel logs is using a KernelLogViewer which integrates with python's logging. Alternatively, custom logging can be implemented.

KernelLogViewer

import logging
import pbk

FORMAT = "%(asctime)s [%(levelname)s] [%(name)s] [%(funcName)s] %(message)s"

logging.basicConfig(
    level=logging.INFO,
    format=FORMAT,
    handlers=[
        logging.FileHandler("my-log.log"),
        logging.StreamHandler()
    ]
)

logger = pbk.KernelLogViewer()

To inspect DEBUG logs, set the appropriate logging.DEBUG level and initialize KernelLogViewer with the categories you want the log output for (or pbk.LogCategory.ALL to view all DEBUG log output, which is noisy).

logging.basicConfig(
    level=logging.DEBUG,
    format=FORMAT,
    handlers=[
        logging.FileHandler("my-log.log"),
        logging.StreamHandler()
    ]
)

logger = pbk.KernelLogViewer(categories=[pbk.LogCategory.VALIDATION])

DEBUG categories can also be enabled temporarily with a context manager. For example, to inspect validation logs during the initialization of a ChainstateManager:

logger = pbk.KernelLogViewer()  # no debug categories are enabled
with logger.temporary_categories(categories=[pbk.LogCategory.LEVELDB]):
    chainman = pbk.load_chainman("/tmp/bitcoin/signet", pbk.ChainType.SIGNET)

[!IMPORTANT] KernelLogViewer objects MUST be kept alive for the duration of the program (or for as long as logging is necessary), the logging connection will automatically be destroyed as soon as the KernelLogViewer object goes out of scope.

Custom logging

KernelLogViewer is a convenience class around the LoggingConnection, which allows any callback that takes a single string argument.

For example, to implement your own logging with a simple print statement:

import pbk

def print_no_newline(msg: str) -> None:
    """`bitcoinkernel` log messages already contain a newline."""
    print(msg, end="")

logging_set_options(pbk.LoggingOptions(log_timestamps=True))
log = pbk.LoggingConnection(cb=print_no_newline)

[!IMPORTANT] LoggingConnection objects MUST be kept alive for the duration of the program (or for as long as logging is necessary), the logging connection will automatically be destroyed as soon as the LoggingConnection object goes out of scope.