Container Lifecycle Hooks exit on non-0 exit code

[Manu10744]

Hi,

i don't understand why Container Lifecycle Hooks are instantly killed by Kubernetes (Exit Code 137) when some command is used that returns a non-0 exit code. Sometimes this is expected behavior and i don't understand why this is not possible with Kubernetes.

For example, in a postStart lifecycle hook, if i am trying to wait for a webservice inside the container to be running like so:

ATTEMPT_COUNTER=0
        MAX_ATTEMPTS=12
        until curl --connect-timeout 2 --silent --output /dev/null --fail https:/mypage. de/tasks/definitions; do
            if [ \${ATTEMPT_COUNTER} -eq \${MAX_ATTEMPTS} ]; then
                echo "Container didnt answer in time. "
                exit 1
            fi 

            ATTEMPT_COUNTER=\$((\$ATTEMPT_COUNTER+1))
            sleep 10
        done

then this will fail instantly as soon as the first curl command fails on Connection refused.

[k8s-ci-robot]

@Manu10744: This issue is currently awaiting triage.

If a SIG or subproject determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[neolit123]

/kind support
/sig node

[alberthuang24]

https://kubernetes.io/docs/tasks/configure-pod-container/attach-handler-lifecycle-event/#discussion.

The Container's state will only change to Running when the postStart hook is successfully executed,

so I don't understand what your question is?

It is also recommended to provide the kubectl version output to help us locate which kubernetes version is the problem

@Manu10744

[alberthuang24]

/triage needs-information

[ehashman]

Kubernetes does not use issues on this repo for support requests. If you have a question on how to use Kubernetes or to debug a specific issue, please visit our forums.

It looks like we have some documentation for this already as linked by @HongjiangHuang but I will also mark this with a docs tag.

/kind documentation
/close

[k8s-ci-robot]

@ehashman: Closing this issue.

In response to this:

Kubernetes does not use issues on this repo for support requests. If you have a question on how to use Kubernetes or to debug a specific issue, please visit our forums.

It looks like we have some documentation for this already as linked by @HongjiangHuang but I will also mark this with a docs tag.

/kind documentation
/close

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.