• Pod : Runs one or more closely related containers(such as Docker containers). Pods are the smallest deployable units of computing that can be created and managed in Kubernetes.

• Service : Sets up networking in k8s cluster.

  Sub types:

  1. ClusterIp : Exposes a set of pods to the other objects in the cluster.
  2. NodePort : Exposes a container to the 'outside world'. (Only good for dev purposes)
  3. LoadBalancer : Legacy way of getting traffic into a cluster
  4. Ingress : Exposes a set of services to the outside world

• Deployment: Maintains a set of identical pods, ensuring that they have the correct config and that the right number exists.

• Secret: Securely stores a piece of info in the cluster, such as db password. Secret types- generic, docker-registry and tls.

kubectl create secret generic <secret name> --from-literal key=value

kubectl create secret generic pgpassword --from-literal PGPASSWORD=password

Command to update image:

kubectl set image <object_type>/<object_name> <container_name> = <new image to use>

kubectl set image deployment/client-deployment client=stephengrider/multi-client:v5

Connect local docker-client with docker-server inside the virtual machine(minikube) (for current terminal window only)

eval $(minikube docker-env)

Delete an object:

kubectl delete deployment postgres-deployment

Redeploy/Restart Deployments: (shortcut)

kubectl scale deployment client-deployment --replicas=0

Helm is a program to administer 3rd party softwares inside k8s cluster. (3rd party softwares like ingress-nginx)

[command we issue] ---> [helm client] ---> [tiller server]

Minikube start with virtualbox (working with Virtual VM - not with hyperkit.):

minikube start --driver=virtualbox

Use -A option to list the requested object(s) across all namespaces:

Eg. kubectl get -A deployments