rm ~/.vimrc

k run nginx --image nginx --dry-run -oyaml > 1.yaml

vim 1.yaml

cat > ~/.vimrc <<EOF
set ts=2 sts=2 sw=2 et nu ai cuc cul
EOF

vim 1.yaml

alias hg='history|grep'

# FILE NAVIGATION AND ORGANISATION
mkdir `seq 20`
ls
cd 1/
cd ../2
cd ../3

# ALWAYS CREATE DRY-RUN YAML FILES WITH 1.yaml, 2.yaml or 3.yaml

k run nginx --image nginx --dry-run -oyaml > 1.yaml

vim 1.yaml

k create -f 1.yaml

k get pod --watch

k get pod nginx -oyaml > 2.yaml

vim 2.yaml

k apply -f 2.yaml

# 6 CLUSTERS IN EXAM
https://docs.linuxfoundation.org/tc-docs/certification/tips-cka-and-ckad

k config use-context [k8s|hk8s|bk8s|wk8s|ek8s|ik8s]

# NAMESPACE TRICK

N=namespace-asked-in-question

k delete ns $N

k create ns $N

k -n $N run question1 --image nginx

k -n $N edit pod question1

# FILENAME TRICK

mkdir -p complete/file/path/

touch complete/file/path/filename-asked-in-question 

F=complete/file/path/filename-asked-in-question

echo $F

cp $F .

ls

vim $F

# HOW TO USE HELP IN COMMAND LINE 
# Identify which objects can be created via command line
# and which objects need yaml to start with

k -h # IT'S ALL STARTS HERE

k expose -h # Use to expose pod or deployment to create a service

k create -h # Ingress, Deployments, SA, role, rolebinding, clusterrole, clusterrolebinding, serviceaccount

k create ingress -h # THIS ONE IS REALLY HANDY

k set -h

k set resources -h # THIS ONE IS REALLY HANDY TOO

k logs -h

k drain -h

k uncordon -h

k scale -h

k top -h

k top pod -h

k top pod --sort-by -h

# Network Policies need yaml first 
https://kubernetes.io/docs/concepts/services-networking/network-policies/

# StorageClass, PersistentVolume, PersistentVolumeClaim need yaml first
https://kubernetes.io/docs/concepts/storage/storage-classes/
https://kubernetes.io/docs/tasks/configure-pod-container/configure-persistent-volume-storage/

# USE EXPLAIN COMMAND

# 1ST FOCUS ON .SPEC FIELD

# IF NOT THEN FOCUS ON .METADATA FIELD

k explain quota.spec --recursive

k explain limitrange.spec --recursive

k explain node --recursive

k explain pod.spec --recursive| grep -i nodesel

k explain deploy.spec --recursive | grep -i nodesel

k explain pod.spec --recursive| grep -i empty -C3

# DON'T ABANDON A COMMAND IF YOU DON'T INTEND TO USE IT IMMEDIATELY
# INSTEAD PRESS CTRL+A TO GO TO START AND ADD A `#` IN FRONT

ETCDCTL_API=3 etcdctl snapshot save \
/tmp/etcd-backup.db \
--cacert /etc/kubernetes/pki/etcd/ca.crt \
--cert /etc/kubernetes/pki/apiserver-etcd-client.crt \
--key /etc/kubernetes/pki/apiserver-etcd-client.key

# GET COMFORTABLE WITH SYSTEMCTL

# sudo -i  # DO SUDO -I if you can

systemctl status kubelet # CHECK SERVICE STATUS

systemctl enable kubelet # ENABLE THE SERVICE

systemctl start kubelet # START THE SERVICE

systemctl stop kubelet # STOP THE SERVICE

systemctl daemon-reload # DAEMON RELOAD

systemctl restart kubelet # RESTART IF YOU MADE ANY CONFIG CHANGES

# VIM TIPS

SHIFT C

vim 1.yaml

SHIFT V -> ARROWS ↑↓ -> y (copy) -> Goto line after which you want to copy -> p (paste after)

vim 1.yaml

SHIFT V -> ARROWS ↑↓ -> `><` -> . (repeat)

vim 1.yaml

k get node

ssh minikube

# sudo -i # become root

# exit # sudo

# exit # exit node

# now you are back to client terminal

hg question1