Incorrect description of readiness probes in course material?

bmbnomis

I think there is a problem in the course material:

The text for exercise 3.3 of LFD259-labs_V2021-12-09.pdf states:

Where the readinessProbe is checked prior to being ready, then not again, the livenessProbe continues to be checked.

Similarly, the readiness probe description in the slides mentions the startup phase of the container only.

AFAIK, only startup probes run only once at startup. readiness probes run during the entire lifecycle of a container (after startup probe, if defined). See: https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/#define-readiness-probes

So, a failing readiness probe will also remove the traffic from the pod at a later point in time (after startup).

TBBle

I also noticed that the startupProbe description on the same slide describes them as "Becoming beta recently", but that was almost two years ago (March 2020, k8s 1.18), and they have in fact left beta to become GA over a year ago (December 2020, k8s 1.20).

lsolovey

@bmbnomis Agree. I was also confused by this description of readiness probe in the course materials.