How to check if a container is running

[Masber]

Is this the right way to check if a container is running?

let mut container_status = pod
    .status
    .clone()
    .unwrap()
    .container_statuses
    .unwrap()
    .into_iter()
    .find(|container| container.name.eq(&my_container.name));

let container_is_running = container_status
      .clone()
      .unwrap()
      .state
      .unwrap()
      .running
      .is_some();

thank you

[imp]

It may be better to avoid .clone() and .unwrap()

use k8s_openapi::api::core::v1 as corev1;

fn container_running(pod: &corev1::Pod, name: &str) -> Option<&corev1::ContainerStateRunning> {
    pod.status
        .as_ref()?
        .container_statuses
        .as_deref()?
        .iter()
        .find(|container| container.name == name)?
        .state
        .as_ref()?
        .running
        .as_ref()
}

fn container_is_running(pod: &corev1::Pod, name: &str) -> bool {
    container_running(pod, name).is_some()
}

[clux]

Seconding using option question mark on pure functions on k8s-openapi / Option-heavy structs where possible. It's a cheap way to avoid erroneous cases if you want to keep the error handling light, but not unwrap-light.

[Masber]

how come returning Option<&corev1::ContainerStateRunning> without a lifetime?

[imp]

Borrow checker groks that this is essentially the same as

fn container_running<'a>(pod: &'a corev1::Pod, name: &'_str) -> Option<&'a corev1::ContainerStateRunning>

[clux]

that should just be tied to the lifetime of the pod arg via lifetime elision i think?

[clux]

Iterating over container status as is done in the main post and imp's answer should both work.

Do note that we already expose the Condition interface for many of these use cases. In particular is_pod_running is similar.

conditions can be used with an await_condition (if you are waiting for a pod to become ready) or you can pass it an Option<&Pod> that you have at hand (if you just want to check).

but if you are looking for one or all containers specifically in that same interface we have a setup like this in test code;

        fn is_each_container_ready() -> impl Condition<Pod> {
            |obj: Option<&Pod>| {
                if let Some(o) = obj {
                    if let Some(s) = &o.status {
                        if let Some(conds) = &s.conditions {
                            if let Some(pcond) = conds.iter().find(|c| c.type_ == "ContainersReady") {
                                return pcond.status == "True";
                            }
                        }
                    }
                }
                false
            }
        }

not exposed yet because there were some uncertainty/laziness around the direction of the conditions module w.r.t. let-chains (which would obviously simplify the look of this code). See #1792

[Masber]

here https://docs.rs/kube/latest/kube/runtime/wait/fn.await_condition.html

what is the the name argument in kube::runtime::wait::await_condition function? is it the container name?

[clux]

it's the .metadata.name of the kind you are asking to watch (in this case Pod name).