<p>I'm trying to find some sort of signal from a cluster indicating that there has been some sort of change with a Kubernetes cluster.  I'm looking for any change that could cause issues with software running on that cluster such as Kubernetes version change, infra/distro/layout change, etc.</p>
<p>The only signal that I have been able to find is a node restart, but this can happen for any number of reasons - I'm trying to find something a bit stronger than this.  I am preferably looking for something platform agnostic as well.</p>

Rishik Hombal
<p>In addition to watching Node events (see the complete list of events <a href="https://github.com/kubernetes/kubernetes/blob/7380fc735aca591325ae1fabf8dab194b40367de/pkg/kubelet/events/event.go#L50" rel="nofollow noreferrer">here</a>), you can use Kubernetes' <strong>Node Problem Detector</strong> for monitoring and reporting about a node's health (<a href="https://kubernetes.io/docs/tasks/debug-application-cluster/monitor-node-health" rel="nofollow noreferrer">link</a>).</p>
<blockquote>
<p>There are tons of node problems that could possibly affect the pods running on the node, such as:</p>
<ul>
<li>Infrastructure daemon issues: ntp service down;</li>
<li>Hardware issues: Bad CPU, memory or disk;</li>
<li>Kernel issues: Kernel deadlock, corrupted file system;</li>
<li>Container runtime issues: Unresponsive runtime daemon;</li>
</ul>
</blockquote>
<p>Node-problem-detector collects node problems from various daemons and make them visible to the upstream layers.</p>
<p>Node-problem-detector supports several exporters:</p>
<ul>
<li><strong>Kubernetes exporter</strong> reports node problems to Kubernetes API server: temporary problems get reported as Events, and permanent problems get reported as Node Conditions.</li>
<li>Prometheus exporter.</li>
<li>Stackdriver Monitoring API.</li>
</ul>
<hr />
<p>Another option is the <strong>Prometheus Node Exporter</strong> (<a href="https://prometheus.io/docs/guides/node-exporter/" rel="nofollow noreferrer">link</a>). It exposes a wide variety of hardware- and kernel-related metrics (<strong>OS release info, system information as provided by the 'uname' system call</strong>, memory statistics, disk IO statistics, NFS statistics, etc.).</p>
<p>Check the list of all existing collectors and the supported systems <a href="https://github.com/prometheus/node_exporter#collectors" rel="nofollow noreferrer">here</a>.</p>
