How to modify format of proxy logs

[kameeloo]

Hi,
My application needs to report every access (like request [not]authenticated, or invalid cert or token or invalid request etc) in a very specific format (json with specific fields and flags; like: USER:, SECURITY-CODE:, etc).
Is there any way to configure proxy to get such format? What are the options to satisfy such a requirement?

Thanks in advance for any response or link.
Regards,
Kamil

[mateiidavid]

Hi @kameeloo,

Our components can be modified to log in a different format through Helm template values. For example:

linkerd2/charts/linkerd-control-plane/values.yaml

Line 122 in 1a3a80d

logFormat: plain

You can look through the supported values here: https://github.com/linkerd/linkerd2/blob/main/charts/linkerd-control-plane/README.md#values

When installing (or upgrading) linkerd, you can specify the value overrides to get logs in a different format. Hope that answers your question :)

[kameeloo]

Thank you. Let my see it and try in a near future.

[stephlal]

@mateiidavid you mentioned that we can specify value overrides to get logs in a different format. I have not see any documentation on how to specify different field and change some of these fields names?

[mateiidavid]

Hey @stephlal, you can change the format of the log records, you can't format the logs themselves. It seems you were asking about the latter? It's not possible to re-name or change fields. You can, however, use different log levels for different parts of the proxy.

Have a look at https://linkerd.io/2.12/reference/proxy-log-level/ for more information.