Pod

What is a Pod?

Pod is an abstraction around one or more containers. Pods provide a context for 1..N containers so that they can share storage and a network. It's very much like how you have used containers to define environments for a single process. They can be thought of as a container of containers. Most of the same rules apply: it is deleted if the containers within stop running and contained files will be lost with it.

Or as kubectl explain pod says

DESCRIPTION:
     Pod is a collection of containers that can run on a host. This resource is
     created by clients and scheduled onto hosts.

See what happens when

kubectl create pod

Error: must specify one of -f and -k

error: unknown command "pod"
See 'kubectl create -h' for help and examples

kubectl create can not create pods (!)

try with

kubectl run whoami --image jwilder/whoami

kubectl get pod

Describe the newly created pod

kubectl describe pod whoami

And then in Lens, select Workloads (from the left) and then Pods.

Then set the namespace in the namespace selector. Notice how you can type in the selector.

And then "describe in lens"

Also, check how you can click access the node from Lens describe pane by clicking it.

Lens "bug": https://github.com/lensapp/lens/issues/6739

Notice how at the end of the describe there are "events" - they come from events resource.

Get all events in the cluster

kubectl get events --all-namespaces

kubectl get events -A

Get events scoped by -namespace

kubectl get events -n __NAME__

Notice how event timestamps are sorted by random, https://stackoverflow.com/questions/45226732/what-kubectl-command-can-i-use-to-get-events-sorted-by-specific-fields-and-print

Find "Events" from the lens and do the same listing of cluster wide and scoped.

This makes no sense, but is fun.

Change the image from jwilder/whoami to nginx with

kubectl set image pod whoami whoami=nginx

See how restart count changes
Check events
Check logs
Run port-forward - note that nginx container port is 80, not 8000

kubectl logs --previous whoami

And same in Lens

Create an index.html

echo "hello" > index.html

and copy it to the container (https://hub.docker.com/_/nginx)

kubectl cp index.html whoami:/usr/share/nginx/html/index.html

Try reloading http://localhost:9999 (hard)

Note, cp works both ways

kubectl cp whoami:/etc/passwd passwd

Delete the namespace to clean up

kubectl delete namespace __NAME__

Notice how get pod listing still "uses" the namespace

kubectl get pod

No resources found in __NAME__ namespace.

You need to reset the namespace back to default

kubectl config set-context --current --namespace=default

Will get pod now list default namespace?

see https://github.com/blendle/kns and https://github.com/ahmetb/kubectx

You have reached the end of this section!