LFD259 - Lab 3.3 - sidecar readiness misunderstanding?

strelko2

Hi all,

I'm not sure if I'm understanding a part of the lab correctly - lab document version is V
2024-09-20

Going through the lab 3.3, we've created a simpleapp deployment, and added a "sidecar" container (using goproxy) in step 9 & 10.
In step 12, we re-create a "healthiness" file.
However, the commentary on step 13 mentions that:

... the Sidecar container in each pod, which was not running, will change status to Running.

From what I understand, the file we touched in step 12 affected the simpleapp container, not the new goproxy sidecar container.
The goproxy container's readiness and liveness probes look self-sufficient to me, as in, the probes check if that same container has the port 8080 ready to go.

A second thing, at least using Kubernetes 1.31, before touching the /tmp/healthy file, both containers are described (in their pod) as "Running"; the difference between them is their Ready attribute, which, indeed, is false for the simpleapp.

Is my understanding correct, or is there something that I'm missing / I've configured incorrectly?

Thank you,
Martin

chrispokorni

Hi @strelko2,

You are correct, the loop that generates the file that flags the healthy state of the container only affects the simpleapp container, and not the goproxy sidecar.

For the given multi-container Pod (simpleapp and goproxy) the outputs of the get and describe commands should reflect the failed probe on the simpleapp container, and the successful probe on the simpleapp container respectively. The goproxy probes should be consistently successful.

Regards,
-Chris