Provide a way to enable core log levels in Quickstart

[anupsdf]

what

Provide a mechanism to enable core's log levels in Quickstart.
stellar-core supports log levels of FATAL, ERROR, WARNING, INFO, DEBUG, TRACE. See --ll in core docs.

why

This would help with troubleshooting issues better. During LayerZero incident if we had a flag to enable core's trace level logging, we could have asked LZ to enable and provide us the logs.

[dmkozh]

I think we probably shouldn't enable trace logging by default (it's extremely verbose), but rather provide a way to restart core with trace logging enabled.

Also, command line is not the only way to change the log level:

• COMMANDS=["ll?level=trace"] in core config would do the same
• Via http command (like sudo -u stellar stellar-core --conf /etc/stellar/stellar-core.cfg http-command "ll?level=trace")

[anupsdf]

I think we probably shouldn't enable trace logging by default (it's extremely verbose), but rather provide a way to restart core with trace logging enabled.

Also, command line is not the only way to change the log level:

• COMMANDS=["ll?level=trace"] in core config would do the same
• Via http command (like sudo -u stellar stellar-core --conf /etc/stellar/stellar-core.cfg http-command "ll?level=trace")

Cool. Editing the title and description.

[anupsdf]

• Via http command (like sudo -u stellar stellar-core --conf /etc/stellar/stellar-core.cfg http-command "ll?level=trace")

Looks like the http command option to toggle core log levels can be used today already by exposing port 11626 when running the container. https://github.com/stellar/quickstart?tab=readme-ov-file#ports

# To expose
docker run -it -p "8000:8000" -p "11626:11626" --name stellar stellar/quickstart --local

# To enable
curl "http://localhost:11626/ll?level=TRACE"

[leighmcculloch]

For the main use case that this image exists, which is supporting development, I can see an argument for exposing the Stellar Core HTTP command endpoint on the main 8000 port. So it's just always available there under some subpath. Unfortunately, people do use this image for non-development use cases, and so I don't think it would be safe for us to just start defaulting to expose that. But for the development use case, that seems like the most obvious way to make this easier to use.

At the very least, and a starting point, we could add some instructions about how to do this to the quickstart readme.

[leighmcculloch]

I think another thing we could do is add an option to the quickstart image, something like --log-level, and then have that value affect all of the applications that are installed. I think all the applications have logs. Some of them have logs where you can control different levels.

We could just have that option be something that increases the log level for all of the applications: core, horizon, RPC, and so on.