Kubernetes Basics provides an overview of Kubernetes concepts and components. It discusses pods vs deployments, scaling deployments, rolling updates, stateful vs stateless applications, daemon sets, secrets, configmaps, services, ingress, storage classes, network policies, and Kubernetes CLI commands. Hands-on examples are given for running commands, exposing services, deleting resources, executing commands in pods, viewing logs, and getting resource information. YAML files are shown for defining deployments, services, and ingress. Skills discussed include using configmaps as environment variables, sidecar deployments, init containers, labels and node selectors, private registries, taints and tolerations, resource management, and readiness and liveness probes.

1. Kubernetes Basics
Simon Su @ 201907
https://shorturl.at/krCDF

2. Objective
● Learning Kubernetes concept
● Kubernetes components overview
● Command line hands on
● Experience share

3. Kubernetes Orchestration

4. Pod vs.
Deployment
- Pod - the smallest unit and cannot
split for runtime
- Replica Set - definition of replicas of
pod
- Deployment - the summary of
pod/replica set

5. Scaling of
Deployment
- Manual scale
- Pod auto scale
- Cluster autoscale

6. Rolling update

7. State of Pod
- Stateful Set - long time running, data
need persistent as possible
- Deployment - short time live,
sessionless and quick startup
From: https://blog.openshift.com/kubernetes-state-storage/

8. Daemon Set
- DaemonSet - live in every node and
only single instance in each node

9. Secret
- Secret - secure info, username,
password… that want to hind at the
first look

10. ConfigMap
- Configuration, documents, startup
script, environment variable…
parameters that change frequently
and extract from container

11. Service expose
- Service - the network entrypoint of
running pods, with service ip address
and can define some network
parameters

12. Ingress
- Layer 7 load balancer and provide
configurable rules for dispatch
traffics to backend deployments

13. Storage Class
- Storage as a service, let user can
define the storage and provide to
pod for use
From: https://cloud.ibm.com/docs/containers?topic=containers-kube_concepts&locale=en-us

14. Network Policy
- Network policy - Between pods
traffic management
- Firewall rule management
From: https://cilium.io/blog/2018/09/19/kubernetes-network-policies/

15. Kubernetes CLI

16. kubectl commands
● run
● expose
● create
● apply
● delete
● get
● describe
● exec
● logs

17. Kubectl - run commands
$ kubectl run nginx --image=image --port=80
$ kubectl get pods,deploy
NAME READY STATUS RESTARTS AGE
po/nginx-1423793266-svb16 1/1 Running 1 5h
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
deploy/nginx 1 1 1 1 5h

18. $ kubectl expose deploy/nginx --type=NodePort
$ kubectl get svc
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes 10.0.0.1 <none> 443/TCP 2d
nginx 10.0.0.227 <nodes> 80:31659/TCP 5h
kubectl - expose

19. kubectl - delete
$ kubectl delete svc/nginx
$ kubectl delete deploy --all

20. kubectl - exec
$ kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-1423793266-svb16 1/1 Running 1 5h
$ kubectl exec -it nginx-1423793266-svb16 bash
root@nginx-1423793266-svb16:/#

21. $ kubectl logs -f nginx-1423793266-svb16
172.17.0.1 - - [24/Oct/2017:17:24:15 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.54.0" "-"
172.17.0.1 - - [24/Oct/2017:17:24:25 +0000] "GET / HTTP/1.1" 200 612 "-" "curl/7.54.0" "-"
$ kubectl logs -f nginx-1423793266-svb16 --tail 30
kubectl - logs

22. $ kubectl get pod,svc,deploy
$ kubectl get all -o wide
NAME READY STATUS RESTARTS AGE IP NODE
po/nginx-1423793266-svb16 1/1 Running 1 5h 172.17.0.3 minikube
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
svc/kubernetes 10.0.0.1 <none> 443/TCP 2d <none>
svc/nginx 10.0.0.37 <nodes> 80:32739/TCP 1m run=nginx
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE CONTAINER(S) IMAGE(S) SELECTOR
deploy/nginx 1 1 1 1 5h nginx nginx run=nginx
NAME DESIRED CURRENT READY AGE CONTAINER(S) IMAGE(S) SELECTOR
rs/nginx-1423793266 1 1 1 5h nginx nginx
pod-template-hash=1423793266,run=nginx
kubectl - get

23. $ kubectl get node
$ kubectl get event
$ kubectl get all --all-namespaces
$ kubectl get pod -l component=web
kubectl - get

24. kubernetes yaml file
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
labels:
run: nginx
name: nginx
spec:
template:
metadata:
labels:
run: nginx
spec:
containers:
- image: nginx
name: nginx
ports:
- containerPort: 80
protocol: TCP
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apiVersion: v1
kind: Service
metadata:
labels:
name: nginx
name: nginx
spec:
type: NodePort
ports:
- port: 80
selector:
name: nginx
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: nginx
spec:
backend:
serviceName: nginx
servicePort: 80
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deployment.yaml service.yaml ingress.yaml

25. kubectl create
$ kubectl create -f deployment.yaml
$ kubectl create -f http://your-service-address/path/deployment.yaml

26. kubectl apply
$ kubectl apply -f deployment.yaml
$ kubectl apply -f http://your-service-address/path/deployment.yaml

27. Skills of Kubernetes Deployment

28. Configmap as
Environment
- Config use for single or multi
deployments
- Using environment parameter to
control

29. Sidecar
deployment
- share the same filesystem
namespace
- share the same network namespace

30. Init container
- Pre-setup environment
- Initialize environment

31. Labels and
Node Selector
- HW select
- Resource allocate
- Network layer distribute

32. Private Registry
- Privacy and secure
- Performance and stable

33. Taint and
Tolerations
- Resource allocation
- Node resource management

34. Resource
management
- cpu, memory limit and request
- custom metrics

35. Readiness
and Liveness
- Prevent 5xx error
- Auto kill unhealthy pod

36. Q&A