Optionally intercept standard Python logging and redirect to loguru handler

[jmarshall]

As per the loguru documentation.

See batch 631674 which ran on an image that includes this PR — note the log ends with log messages from modules within /cpg-flow/.venv/lib/… whereas batch 631672 is of similar vintage but does not contain this PR and omits these log messages.

Before merging this, we would need to consider whether we facilitate cpg-flow-using workflows that prefer standard logging rather than loguru, and what the desired behaviour there would be — perhaps to redirect cpg-flow's loguru messages to the standard logger instead.

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[dancoates]

Looks good, a bit of a fiddly implementation but as per the docs you linked this does seem to be the advised way to have loguru intercept standard logging.

[jmarshall]

Indeed… You would think loguru could provide a suitable default InterceptHandler rather than inviting everyone to write it themselves…

ETA: Requested three years ago: Delgan/loguru#633.

[nevoodoo]

Hey @jmarshall is this okay to merge still?

[jmarshall]

Before merging this, we would need to consider whether we facilitate cpg-flow-using workflows that prefer standard logging rather than loguru, and what the desired behaviour there would be — perhaps to redirect cpg-flow's loguru messages to the standard logger instead.

I still think it would be worth looking at whether there are standard-logging-using flow-based repos and if so what the effect of this on them is. But perhaps just merging this and crossing that bridge when we come to it suffices.

[jmarshall]

I suppose the PR builds in enough ways to switch it off that we could just merge it and expect any flow-based repos for which it's a problem to turn it off, either in config or format_logger call.