https://useinov.com/tags/kubernetes/ Recent content in Kubernetes on Murat Useinov Hugo en-us Wed, 07 Aug 2019 18:05:00 +0300 https://useinov.com/posts/2019/kubernetes-probes-php/ Wed, 07 Aug 2019 18:05:00 +0300 https://useinov.com/posts/2019/kubernetes-probes-php/ <p>Route <code>/health</code>, returns <code>ok</code>, everyone happy. That is the first version of every health endpoint on the project we are moving to Kubernetes. Then somebody pastes the same path into <code>livenessProbe</code> and <code>readinessProbe</code>, and a thirty second database hiccup becomes a long evening.</p> <p>The two probes ask different questions.</p> <p>Readiness asks: should this pod get traffic right now. Here it is correct to check dependencies. Database unreachable, cache cold, migrations still running: answer no. Kubernetes takes the pod out of the Service, traffic goes to the others, the pod returns when the world improves. Failing readiness is cheap and reversible. A polite &ldquo;not now&rdquo;.</p>