Exercise 3.4: and v1-17.docs.kubernetes.io resources

suser

Hello,
Are these images k8s.gcr.io/goproxy:0.1 and k8s.gcr.io/liveness we can see at https://v1-17.docs.kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-startup-probes/ nginx servers images we can use during exam? All we have to do is to use yaml files available there?

Thank you in advance!
Stefan

chrispokorni

Hi Stefan,

As it was previously mentioned, please browse through the certification resources in order to find answers to exam specific questions. If the resources do not cover a specific concern (directly or indirectly), then please direct your question to certificationsupport@linuxfoundation.org.

This forum is a tool dedicated to course learners and it aims to provide solutions related to course-related topics and exercises.

Regards,
-Chris

suser

What the line "- /server" means at yaml https://raw.githubusercontent.com/kubernetes/website/master/content/en/examples/pods/probe/http-liveness.yaml ?
If I add lines "args:- /server" with nginx alpine image the container wont start due to daemon error:

Error: failed to start container "webserver": Error response from daemon: OCI runtime create failed: container_linux.go:349: starting container process caused "exec: \"/server\": stat /server: no such file or directory": unknown

Stefan

chrispokorni

Hi Stefan,

This is related to how containers work. That is an argument passed to the liveness container. The reason that the same argument crashes the nginx container is purely because the nginx container does not accept the same argument, but may work with other arguments instead.

Regards,
-Chris

suser

Can you shortly describe please how this argument works in the given yaml example, it will help me better understand what happens under the hood. Is this argument parsed by docker during container creation? Or by nginx server after creation?

Thank you.

Stefan

chrispokorni

In order to understand containers and what they do, I recommend taking an intro course in containers, or exploring the Docker documentation - more specifically the Dockerfile, the docker build, and docker run commands.

Regards,
-Chris