Kube && Helm

- K8s how to collect metrics

- Kubernetes API Explained

- Kubernetes POD Draining for Node Maintenance

- Isolate a Pod Kubernetes

- Deploy metrics-server in Kubernetes using Helm

- Kube state metrics

- K Ingress

- K8s CoreDns

k get pods -n=kube-system

k get deploy -n=kube-system

k scale deploy coredns --replicas=2 -n=kube-system

k get pods -n=kube-system

k exec -it nginx -- curl nginx1

k get svc -n=kube-system (kube-dns|ClusterIP)\

cat /etc/resolv.conf

search default.svc.cluster.local svc.cluster.local

nameserver ip

cat /etc/hosts --> add entry in /etc/hosts

 - K9s Demo

a) arkade | grep k9s

b) column - shortcut gives us access between resources

c) Ctrl + A gives us access to all resources.

d) Logs can be seen by accessing pod

- Get deployments and statefullsets in log

┌─[bo@ldap]─[~]

└──╼ $kubectl get -A Deployments | tee -a log.txt

NAMESPACE     NAME      READY   UP-TO-DATE   AVAILABLE   AGE

kube-system   coredns   1/1     1            1           72d

┌─[bo@ldap]─[~]

└──╼ $kubectl get -A StatefulSets | tee -a og.txt

No resources found

- SideCar pods - sidecar

- Rolling update strategy

- DaemonSet-Deployment-StatefullSets

- NodePort-Ingress-LoadBalancer

Nginx Ingress Controller

- Kube deployments: Get started

- Get gcloud context

gcloud auth login

kubectl config current-context 

- DaemonSets

a) find api version: 

    kubectl api-resources | grep daemonset

b) the api resource must match helm

c) name of the daemon set first and second and third the names of pods