Configurable log levels in Cillium are completely undocumented

[matin-nayob]

Feature Requests

Hi there,

It would be great if it was possible to configure the log level of Cilium.
By default, it looks like Cilium logs at the Info level, with the --debug argument enabling lower levels of logs.

It would be great if this could be more configurable so that, for example, Cilium would only log Warnings and above.

Thanks

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Update 2023-11: We support configurable logging, but it is entirely undocumented. That should be fixed.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[stale]

This issue has not seen any activity since it was marked stale. Closing.

[jjchambl]

I know this is an old issue, but this seems a simple enough configuration option, so long as Cilium uses log levels correctly already. I've only seen info level logs so far in my limited usage of it (no warning or errors yet), but they occur at a very large volume in our clusters (running 10-20 nodes), which adds up when they're being streamed to a log aggregator like Datadog.

[rolinh]

The feature request makes sense to me and given the high interest in it, let's keep it open.

[jjchambl]

Happy to help contribute, even if it's just documentation, but haven't worked with the codebase before, so would need some pointers to get started.

[squeed]

I believe this is already complete. However, it is not well documented. We support the Helm value logOptions (or the equivalent ConfigMap flag log-opt) which takes a json blob of configuration or key=value pairs.

I believe you can add the Helm value

logOptions: "level=warning"

and it should work.

[jjchambl]

That's good news. I'll try it out, if it works I'll look at adding some documentation to that effect.

[jjchambl]

@squeed have confirmed that your suggestion works. I've set a task for my team to investigate this setting a bit more, and once we've worked with it a bit we'll make a PR into the helm docs repo. Thanks so much!

[jjchambl]

@squeed after further testing, I can't get a value to go through the helm chart that will successfully parse in the Go template (using, for instance a flag like --set logOptions="level=warn"). I need to manually change the configmap to have the correct values.

EDIT: I forgot that Helm has a set-json feature. Using this option worked with the Helm chart. Will be adding a docs PR shortly.