Go client SDK: check if a Deployment is fully ready - kubernetes

Question

Say I have an in-memory Deployment object, what is the correct way of testing if it is fully ready? (not in the progress of rollout, upgrade or rollback).

Answer 1

I can't comment, so it will have to be an answer.
I don't think there is a right way of doing this, as it depends on a number of variables. Such as what languages you are proficient with etc.
Where I work, we run a kubectl get pods and grep the information that is relevant (in this case if the pod is available (ready) or not. This is all run through bash as part of a startup script:
function not_ready_count() {
kubectl ${1} get pods -o json | jq -r '.items[].status.conditions[].status' | grep False | wc -l | awk '{ print $1 }'
}
function not_running_count() {
kubectl ${1} get pods -o json | jq -r '.items[].status.phase' | grep -v Running | wc -l | awk '{ print $1 }'
}
function wait_until_running_and_ready() {
sleep 2
while [[ "$(not_running_count ${1})" != "0" ]]; do
echo "waiting for $(not_ready_count ${1}) pods to start"
sleep 3
done
while [[ "$(not_ready_count ${1})" != "0" ]]; do
echo "waiting for $(not_ready_count ${1}) status probes to pass"
sleep 3
done
sleep 2
}

Answer 2

Following is my implementation to check if a deployment is Ready using client-go:
package main
import (
"context"
"flag"
"fmt"
"path/filepath"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/client-go/kubernetes"
"k8s.io/client-go/tools/clientcmd"
"k8s.io/client-go/util/homedir"
)
func main() {
var kubeconfig *string
if home := homedir.HomeDir(); home != "" {
kubeconfig = flag.String("kubeconfig", filepath.Join(home, ".kube", "config"), "(optional) absolute path to the kubeconfig file")
} else {
kubeconfig = flag.String("kubeconfig", "", "absolute path to the kubeconfig file")
}
flag.Parse()
config, err := clientcmd.BuildConfigFromFlags("", *kubeconfig)
if err != nil {
panic(err)
}
clientset, err := kubernetes.NewForConfig(config)
if err != nil {
panic(err)
}
deploymentsClient := clientset.AppsV1().Deployments("my-namespace")
deploy, err := deploymentsClient.Get(context.Background(), "my-deploy", metav1.GetOptions{})
if err != nil {
panic(err)
}
if deploy != nil &&
deploy.Spec.Replicas != nil &&
*deploy.Spec.Replicas == deploy.Status.ReadyReplicas {
fmt.Println("Deployment is READY")
} else {
fmt.Println("Deployment is NOT READY")
}
}