[coredump] Add sizelimit for coredump

[jcastill]

While most coredumps could be relatively small,
in certain environments, like Ceph, these can be
as big as 5GB. This change adds a limit of 100MB
to the latest core collection.

Related: RHEL-62972

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[packit-as-a-service]

Congratulations! One of the builds has completed. 🍾

You can install the built RPMs by following these steps:

• sudo yum install -y dnf-plugins-core on RHEL 8
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• And now you can install the packages.

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[pmoravec]

This would mean we grab 100MB of incomplete / usefulness data for coredumps >100MB. Not great though no idea how to simply prevent that.

[jcastill]

OK, I thought it was "grab the file only if max is 100MB". I'll add a check then, because incomplete core dumps are useless

[jcastill]

@pmoravec some options:
a- Stop gathering the latest coredump.
b- Increase the limit for coredumps smaller than, lets say, 500M
c- Add an option to add_cmd_output for 'max_size' that only gathers commands less than that argument?
d- Add an option 'tailit' like in add_copy_spec, so if size is bigger than sizelimit and it's a binary, skip the collection and log it?
e- Other option I didn't think about?

[TurboTurtle]

OK, I thought it was "grab the file only if max is 100MB". I'll add a check then, because incomplete core dumps are useless

That's for binary files. This is a command capture.

c- Add an option to add_cmd_output for 'max_size' that only gathers commands less than that argument?
d- Add an option 'tailit' like in add_copy_spec, so if size is bigger than sizelimit and it's a binary, skip the collection and log it?

We would need to hold the entire command output in memory to determine its size, which is not desirable here. Any sizelimit that isn't 0 means we store it in memory, otherwise we write directly to a file to not potentially OOM systems where command output can be large.

[TurboTurtle]

I see there's a lot we can do with the info output, and generally spruce up the collections at large. I'll throw something together and get something posted on my lunch.