Debugging your Kubernetes cluster

During any step of our adventure with Minikube & GCP we gave you some sample command regarding how to debug your project. Below is the list of command that can be useful to debug your Kubernetes environment.

Watch for your deployment¶

You can use a watcher command which will allow you to see the status of your deployment

kubectl rollout status deployments.v1.apps/<deployment_name>

# Response type
deployment <deployment_name> successfully rolled out

I guess it should be the same for the replicaSets and other kind of Controller & API Services

Debug your pod¶

You can debug in 2 ways. First by looking at the events of the pods itself which can show e.g: if the container has been successfully created or not

kubectl describe pod <pod_id>

# Look for the events section

In the other hand you could also get the logs of your pod

kubectl logs -p <pod_id>

You can also run

kubectl get pods

# Response type

NAME                         READY     STATUS    RESTARTS   AGE
bobba-api-7894d6765d-8lm7q   2/2       Running   0          2h
bobba-api-7894d6765d-ch9qn   2/2       Running   0          2h
bobba-vue-54bb88c7bb-466cb   1/1       Running   0          1d
bobba-vue-54bb88c7bb-n4fpd   1/1       Running   0          1d

and look for the error such as CrashLoopBackoff

Debug your services¶

Like debugging your pod you can query the describe API for debugging your service like so

kubectl describe service <service_id>

# Response type
Name:                     bobba-api
Namespace:                default
Labels:                   <none>
Annotations:              <none>
Selector:                 app=bobba-api,tier=backend
Type:                     NodePort
IP:                       <ip>
Port:                     <unset>  80/TCP
TargetPort:               8000/TCP
NodePort:                 <unset>  31320/TCP
Endpoints:                <pod ip>:8000,<pod ip>:8000
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

Connect to your nodes¶

You can connect to your Nodes cluster by doing this command. This allow you to see the logs of the kubelet and internal Kubernetes components

First you have to find your instances with this command

gcloud compute instances list

gcloud compute ssh <cluster_instance_pool_name> --zone <zone of your cluster>

# e.g gcloud compute ssh gke-bubbletea-cluster-default-pool-ABCD --zone us-central1-a

Note: If you don’t find your instance make sure that you are using the right project. Find your project by using this command

gcloud projects list

then set the right project

gcloud config set project <project_id>