<p>Is there a way to change the logging level on a running cluster, specifically for a single system component such as kube-proxy?  </p>

<p>I see some discussion related to this:<br>
<a href="https://github.com/kubernetes/test-infra/pull/4311" rel="nofollow noreferrer">https://github.com/kubernetes/test-infra/pull/4311</a>
and it seems like some sort of a mechanism was put in place, but it is not clear to me how to use this mechanism.</p>

<p>This question came about because we are troubleshooting connections to a NodePort service (which should go through kube-proxy), and at the default level of --v=2 kube-proxy doesn't seem to log any of the connections that it proxies, so seeking to increase it.   </p>

<blockquote>
  <p>it seems like some sort of a mechanism was put in place, but it is not clear to me how to use this mechanism</p>
</blockquote>

<p>I didn't see anything in that PR that would lead me to believe there is a dynamic (that is: without terminating <code>kube-proxy</code>) mechanism for altering log levels. There is no dynamic logging adjustment mechanism that I'm aware of in any of the kubernetes components.</p>

<p>However, <code>kube-proxy</code> (traditionally) runs in a docker container just like any other Pod, and thus is subject to being restarted on termination. So just update its <code>--v</code> in the manifest, kill the container (the one without <code>Pod</code> in its name), and <code>kubelet</code> will start <code>kube-proxy</code> back up, now with the new <code>--v</code> level.</p>

<blockquote>
  <p>(which should go through kube-proxy)</p>
</blockquote>

<p>Just for clarity, <code>kube-proxy</code> only manages the <code>iptables</code> rules in its default configuration, and so no traffic flows through it that I'm aware of. That's actually why it's safe to just restart <code>kube-proxy</code> at will.</p>

<p>You can examine the rules it puts into place with the regular <code>iptables -t nat -L</code> command, and <code>kube-proxy</code> is even helpful enough to add comments to the rules, showing which kubernetes service they represent.</p>
