## Healthcheck Probe

MinIO server has two healthcheck related un-authenticated endpoints, a liveness probe to indicate if server is responding, cluster probe to check if server can be taken down for maintenance.

- Liveness probe available at `/minio/health/live`
- Cluster probe available at `/minio/health/cluster`

# MinIO Healthcheck

MinIO server exposes three un-authenticated, healthcheck endpoints liveness probe and a cluster probe at `/minio/health/live` and `/minio/health/cluster` respectively.

## Liveness probe

This probe always responds with '200 OK'. Only fails if 'etcd' is configured and unreachable. When liveness probe fails, Kubernetes like platforms restart the container.

```
livenessProbe:
  httpGet:
    path: /minio/health/live
    port: 9000

| HOST_PROBE_SNAT_IP | "169.254.7.127" | Applied to SNAT host probe packets, so they can be identified/skipped podside. Any link-local address in the 169.254.0.0/16 block can be used |

  repeated VolumeDevice volumeDevices = 21;

  // Probes are not allowed for ephemeral containers.
  // +optional
  optional Probe livenessProbe = 10;

  // Probes are not allowed for ephemeral containers.
  // +optional
  optional Probe readinessProbe = 11;

  // Probes are not allowed for ephemeral containers.
  // +optional
  optional Probe startupProbe = 22;

* Kubelet now exposes a new endpoint, `/metrics/probes`, which exposes a Prometheus metric containing the liveness and/or readiness probe results for a container. ([#61369](https://github.com/kubernetes/kubernetes/pull/61369), [@rramkumar1](https://github.com/rramkumar1))

### SIG Network

### Deprecated/changed metrics

- kubelet probe metrics are now of the counter type rather than the gauge type, and the `prober_probe_result` has been replaced by `prober_probe_total`. ([#76074](https://github.com/kubernetes/kubernetes/pull/76074), [@danielqsj](https://github.com/danielqsj))

- A bug was fixed in kubelet where exec probe timeouts were not respected. This may result in unexpected behavior since the default timeout (if not specified) is `1s` which may be too small for some exec probes. Ensure that pods relying on this behavior are updated to correctly handle probe timeouts. See [configure probe](https://docs.k8s.io/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#configure-probes) section of the documentation for more details.

- Limit the body length of exec readiness/liveness probes. remote CRIs and Docker shim read a max of 16MB output of which the exec probe itself inspects 10kb. ([#82514](https://github.com/kubernetes/kubernetes/pull/82514), [@dims](https://github.com/dims))

  - Health check (liveness & readiness) probes using an HTTPGetAction will no longer follow redirects to different hostnames from the original probe request. Instead, these non-local redirects will be treated as a Success (the documented behavior). In this case an event with reason "ProbeWarning" will be generated, indicating that the redirect...

- Kubeadm: make sure the etcd static pod startup probe uses /health?serializable=false while the liveness probe uses /health?serializable=true&exclude=NOSPACE. The NOSPACE exclusion would allow administrators to address space issues one member at a time. ([#110744](https://github.com/kubernetes/kubernetes/pull/110744), [@neolit1...