We have defined K8s liveness and readiness probes in our deployment resource (we have defied there liveness...), we need with client-go lib to access this liveness probe, how can we do that?
I've tried it with the client-go lib
https://github.com/kubernetes/client-go
as follows:
client.Discovery().RESTClient().Get()I've also tried to play around with the go library but did not find any deployment property on client.CoreV1(). However I do find service pod etc. What am I missing here?
PodList, err := client.CoreV1().Pods("mynamespace").List(metav1.ListOptions{LabelSelector: "run=liveness-app"})
At the end I need to get the pod liveness status according to the liveness probe which is defined in the deployment. I mean live or dead
How to do this depends on what you want to do.
The Deployment contains a PodTemplate, that is used for creating each replica.
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
app: myapp
name: myapp
spec:
replicas: 2
selector:
matchLabels:
app: myapp
template:
metadata:
labels:
app: myapp
spec:
containers:
- image: myimage
name: myapp
livenessProbe:
# your desired liveness checkYou can get the desired PodTemplate from deployments using client-go
For example:
clientset := kubernetes.NewForConfigOrDie(config)
deploymentClient := clientset.AppsV1().Deployments("mynamespace")
deployment, err := deploymentClient.Get("myapp", metav1.GetOptions{})
for _, container := range deployment.Spec.Template.Spec.Containers {
container.LivenessProbe // add your logic
}
Note: The Deployment only contains the desired PodTemplate, so to look at any status, you have to look at the created Pods.
You can list the Pods created from the deployment by using the same labels as in the selector of the Deployment.
Example list of Pods:
pods, err := clientset.CoreV1().Pods(namespace).List(metav1.ListOptions{
LabelSelector: "app=myapp",
})
// check the status for the pods - to see Probe status
for _, pod := range pods.Items {
pod.Status.Conditions // use your custom logic here
for _, container := range pod.Status.ContainerStatuses {
container.RestartCount // use this number in your logic
}
}
The Status part of a Pod contain conditions: with some Probe-information and containerStatuses: with restartCount:, also illustrated in the Go example above. Use your custom logic to use this information.
A Pod is restarted whenever the livenessProbe fails.
Example of a Pod Status
status:
conditions:
- lastProbeTime: null
lastTransitionTime: "2020-09-15T07:17:25Z"
status: "True"
type: Initialized
containerStatuses:
- containerID: docker://25b28170c8cec18ca3af0e9c792620a3edaf36aed02849d08c56b78610dec31b
image: myimage
imageID: docker-pullable://myimage@sha256:a432251b2674d24858f72b1392033e0d7a79786425555714d8e9a656505fa08c
name: myapp
restartCount: 0pods, err := client.CoreV1().Pods("").List(meta_v1.ListOptions{})
if err != nil {
log.Fatal(err)
}
for _, pod := range pods.Items {
for _, container := range pod.Spec.Containers {
fmt.Println(container.LivenessProbe)
fmt.Println(container.ReadinessProbe)
}
}
You can iterate over pod.Items to get the container LivenessProbe and ReadinessProbe