import_linux_command

lets start kubenetes

One Node Master and worker

sudo nano /etc/fstab

sudo swapoff -a

sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl gnupg

sudo tee /etc/sysctl.d/kubernetes.conf <<EOF
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
overlay
br_netfilter
EOF
sudo sysctl --system
sudo modprobe overlay
sudo modprobe br_netfilter

sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmour -o /etc/apt/trusted.gpg.d/containerd.gpg
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"
sudo apt update


sudo apt install containerd.io -y

sudo containerd config default | sudo tee /etc/containerd/config.toml
sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml
sudo systemctl restart containerd


sudo mkdir -p /etc/apt/keyrings

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/k8s.gpg

echo "deb [signed-by=/etc/apt/keyrings/k8s.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /" | sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt update

sudo apt install kubelet kubeadm kubectl -y
sudo apt-mark hold kubelet kubeadm kubectl
==========================================================================
sudo kubeadm init --pod-network-cidr=192.168.0.0/16

mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml

import kubenetes command

kubeadm token create --print-join-command

kubectl get nodes

kubectl get pods --all-namespaces --watch

import command kubectl

kubectl cluster-info

kubectl get nodes
kubectl get nodes -o wide
kubectl get pods --namespace kube-system

kubectl get pods --namespace kube-system -o wide

kubectl get pods --all-namespaces --watch

kubectl get pods pod1 --output=yaml

kubectl create deployment nginx --image=nginx

kubectl get all --all-namespace | more


kubectl api-resouces | more


kubectl api-resource |grep pod


#explain

kubectl explain pod | more

kubectl explain pod.spec | more

kubectl explain pod.spec.containers | more


kubectl describe nodes worker1 | more

kubectl get -h | more

kubectl get -h | more

sudo apt install bash-completion

echo "source <(kubectl completion bash)" >> ~/.bashrc

source ~/.bashrc

kubectl g[tab]

Application Deployment in kubernetes

kubectl create deployment nginx --image=nginx

kubectl run nginx --image=nginx

* Declarative

Define out desired state in code 

Manifest

kubectl apply -f deployment.yaml

sample1

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-world
spec:
  replicas: 1
  selector:
    matchiLabels:
      app: hello-world
template:
   metadata:
    labels:
        app: hello-word
    spec:
      containers:
      - image: gcr.io/google-sample/hello-app:1.0
        name: hello-app

kubectl apply -f deployment.yaml

Generating Manifests with dry-run

kubectl create deployment hello-world --image=gcr.io/google-sample/hello-app:1.0 --dry-run=client -o yaml > deployment.yaml

Demo

kubectl create deployment hello-world --image=gcr.io/google-samples/hello-app:1.0

kubectl run hello-world-pod --image=gcr.io/google-samples/hello-app:1.0

* if made mistake

kubectl delete deployment hello-world
kubectl create deployment hello-world --image=gcr.io/google-samples/hello-app:1.0

or
kubectl delete pod hello-world-pod

kubectl get pods
kubectl get pods -o wide

When containerd is your container runtime, use crictl to get a listing of the containers running

Check out this for more details http://kubernetes.io/docs/tasks/debug-application-cluster/crictl

sudo crictl --runtime-endpoint unix:///run/containerd/containerd.sock ps

or 

ctr container ls

back on c1-cp1 we can pull the logs from the container

Lanunch a shell into the container

kubectl logs hello-world-pod

kubectl exec -it hello-world-pod -- /bin/sh
hostname
ip addr

Deployment

kubectl get deployment hello-world
kubectl get replicast
kubectl get pods

kubectl describe replicaset hello-world |more

kubectl describe pod hello-world |more

export deployment as service

kubectl expose deployment hello-world --port=80 --target-port=8080

Check out the Cluster-ip

kubectl get service hello-world

kubectl describe service hello-world

curl http://$serverIp:$port

Using kubnect to generate yaml or json

kubectl get deployment hello-world -o yaml | more
kubectl get deployment hello-world -o json | more

Deleting the deployment will delete the replicaset and all deployment test

kubectl get all
kubectl delete service hello-world
kubectl delete deployment hello-world
kubectl delete pod hello-world-pod
kubectl get all

create service file and deployment in the one command

kubectl expose deployment hello-world --port=80 --target=8080 --dry-run=client | more


#### Write the Service yaml manifest to file

kubectl expose deployment hello-world --port=80 --target-port=8080 --dry0run=client -o yaml > service.yaml

more service.yaml

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: hello-world
  name: hello-world
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8080
  selector:
    app: hello-world
status:
  loadBalancer: {}

kubectl apply -f service.yaml

** Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: hello-world
  name: hello-world
spec:
  replicas: 20
  selector:
    matchLabels:
      app: hello-world   #Match
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: hello-world #Match
    spec:
      containers:
      - image: gcr.io/google-samples/hello-app:1.0
        name: hello-app
        resources: {}
status: {}

kubectl apply -f deployment.yaml

kubectl get service
NAME          TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE
hello-world   ClusterIP   10.97.90.181   <none>        80/TCP    20m
kubernetes    ClusterIP   10.96.0.1      <none>        443/TCP   4d22h
root@master1:~# curl 10.97.90.181
Hello, world!
Version: 1.0.0
Hostname: hello-world-7768b7869f-622dp

The deployment is scaled to 30 and we have 30 pods

kubectl get deployment hello-world

You can also scale a deployment using scale

kubectl scale deployment hello-world --replicas=40
or
kubectl scale deployment hello-world --replicas 40

Clean up our deployment

kubectl delete deployment hello-world
kubectl delete service hello-world
kubectl get all

Managing Kubernetes Controllers and Deployments

Maintainig Application with Deployments
Deploying and Maintaining Applications with DaemonSets and jobs

kubectl get --namespace kube-system deployment coredns

kubectl get --namespace kube-system daemonset

kubectl get nodes

Decelrative

kubectl create deployment hello-wold --iamge=gcr.io/google-samples/hello-app:1.0
kubectl scale deployment hello-world --replicas=5

impractive

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: hello-world
  name: hello-world
spec:
  replicas: 20
  selector:
    matchLabels:
      app: hello-world   #Match
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: hello-world #Match
    spec:
      containers:
      - name: hello-app
        image: gcr.io/google-samples/hello-app:1.0
        ports:
        - containerPort: 8080

kubectl apply -f deployment2.yaml
kubectl get replicasets.apps
kubectl get deployment
kubectl get pods
kubectl delete -f deployment2.yaml

apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: hello-world
  name: hello-world
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8080
  selector:
    app: hello-world
status:
  loadBalancer: {}

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  labels:
    app: hello-world
  name: hello-world
spec:
  replicas: 20
  selector:
    matchLabels:
      app: hello-world   #Match
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: hello-world #Match
    spec:
      containers:
      - name: hello-app
        image: gcr.io/google-samples/hello-app:1.0
        ports:
        - containerPort: 8080

apiVersion: apps/v1
kind: ReplicaSet
...
spec:
  replicas: 20
  selector:
    matchExpressions:
      - key: app
        operator: In
        values:
          - hello-world-pod-me
  template:
    metadata:
      labels:
        app: hello-world #Match
    spec:
      containers:
      ...

Isolating a Pod from a ReplicaSet

For more coverage on this see, Managing the kubernetes API

kubectl get pods --show-labels


kubectl label pod hello-world-f597  app=hello-world-pod-me --overwrite

kubectl get nodes --watch

kubectl get nodes -o wide --watch

kubectl get pods --watch

Updating a Deployment Object

kubectl set image deployment hello-world hello-world=hello-app:2.0

kubectl set image deployment hello-world hello-world=hello-app:2.0 --record

kubectl edit deployment hello-world

kubectl apply -f hello-world-deployment.yaml --record

if you change the deployment.v2.yaml I mean change the version then aplly again

Checking Deployment status

kubectl rollout status deployment [name]
kubectl descrive deployement [name]

echo $?


* show history
kubectl rollout history deployment hello-world

* bash to last version I mean v2 to v1
kubectl rollout undo deployment hello-world

* check it roull out work immediatly or not

kubectl rollout status deployment hello-world

* back to specific version
kubectl rollout undo deployment hello-world --to-revision=2

```yaml
kubectl rollout history deployment hello-world --revision=1
deployment.apps/hello-world with revision #1
Pod Template:
  Labels:	app=hello-world
	pod-template-hash=84c65f5f46
  Containers:
   hello-app:
    Image:	gcr.io/google-samples/hello-app:1.0
    Port:	8080/TCP
    Host Port:	0/TCP
    Environment:	<none>
    Mounts:	<none>
  Volumes:	<none>
  Node-Selectors:	<none>
  Tolerations:	<none>

Using Deployment to Change state

Update strategy
Pause to make corrctions
Rollback to an earlier version
Restart Deployment

Controls Pods rollout RollingUpdate (default)

A new ReplicaSet starts scalingh up and the old ReplicaSet starts scaling download

Recreate Terminates all Pods in the current ReplicaSet set prior to scaling up the new ReplicaSet

Used when applicationm don't suppot running diffrent versions cincurrently

apiVersion: apps/v1
kind: Deployment
...
spec:
  replicas: 20
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 20%
      maxSurge: 5
...
template:
...
   spec:
     containers:
...  
      readinessProb:
        httpGet:
          path: /index.html
          port: 8080
        initialDelaySeconds: 10
        periodSeconds: 10

Pausing and Resuming a Deployment.
changes to the Deployment while paused are not rolled out
Batch changes togetherm then resumes the rollout

starts Up a new ReplicaSet with the new changes

kubectl rollout paused deployement my-deployment
kubectl rollout resume my-deployment

rolling Back Deployment

kubectl rollout history deployment hello-world

kubectl rollout history deployment hello-world --revision=1

kubectl rollout undo deployment hello-world

kubectl rollout undo deployment hello-world --to -revision=1

REstarting a Deployment

Effectively restarts all the Pods But no Pod is ever "recreated" New ReplicaSet with the same Pod spec Uses Deployment's Update strategy
RollingUpdate
Recreate

kubectl rollout restart deployement hello-world

Observe behavior since new image wasn't available, the ReplicaSet doesn't go below maxUnavailable

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: hello-world
  name: hello-world
spec:
  progressDeadlineSeconds: 10
  replicas: 10
  selector:
    matchLabels:
      app: hello-world   #Match
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: hello-world #Match
    spec:
      containers:
      - name: hello-app
        image: gcr.io/google-samples/hello-ap:2.0
        ports:
        - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: hello-world
  name: hello-world
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8080
  selector:
    app: hello-world
status:
  loadBalancer: {}

kubectl apply -f deployment2.yaml

kubectl apply -f deployment.broken.yaml

### why isn't this finisheing...? after progressDeadlineSeconds which we set to 10 seconds (default to 10 minutes)
kubectl rollout status deployment hello-world

kubectl get pods
NAME                           READY   STATUS             RESTARTS   AGE
hello-world-66f5964f8c-6v7gb   0/1     ImagePullBackOff   0          99s
hello-world-66f5964f8c-9bxhm   0/1     ImagePullBackOff   0          99s
hello-world-66f5964f8c-blspc   0/1     ErrImagePull       0          99s
hello-world-66f5964f8c-gvx6j   0/1     ImagePullBackOff   0          99s
hello-world-66f5964f8c-mtvbw   0/1     ImagePullBackOff   0          99s
hello-world-84c65f5f46-2bzlw   1/1     Running            0          108s
hello-world-84c65f5f46-5n6j5   1/1     Running            0          109s
hello-world-84c65f5f46-k74x9   1/1     Running            0          108s
hello-world-84c65f5f46-qwbdc   1/1     Running            0          108s
hello-world-84c65f5f46-sd4tz   1/1     Running            0          109s
hello-world-84c65f5f46-trkg9   1/1     Running            0          109s
hello-world-84c65f5f46-v2cfj   1/1     Running            0          109s
hello-world-84c65f5f46-xm896   1/1     Running            0          108s

kubectl describe deployments hello-world

kubectl rollout history deployment hello-world

kubectl describe deployments hello-world  | head
## you can see Annotations:            deployment.kubernetes.io/revision: 2

kubectl rollout history deployment hello-world --revision=2

kubectl rollout history deployment hello-world --revision=1

### Let's under out rollout to revision2, which is our v2 container.

kubectl rollout undo deployment hello-world --to-revision=2

kubectl rollout status deployment hello-world

echo $?

Demo 3 Controlling the rate and update strategy of a Deployment update.

Let's deploy a Deployment with Readliness Probes

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: hello-world
  name: hello-world
spec:
  progressDeadlineSeconds: 10
  replicas: 10
  selector:
    matchLabels:
      app: hello-world   #Match
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: hello-world #Match
    spec:
      containers:
      - name: hello-app
        image: gcr.io/google-samples/hello-app:1.0
        ports:
        - containerPort: 8080
        readinessProbe:
          httpGet:
            path: /index.html
            port: 8080
          initialDelaySeconds: 10
          periodSeconds: 10
---
apiVersion: v1
kind: Service
metadata:
  creationTimestamp: null
  labels:
    app: hello-world
  name: hello-world
spec:
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8080
  selector:
    app: hello-world
status:
  loadBalancer: {}

kubectl apply -f deployment.probes-1.yaml --record
kubectl describe deployment hello-world

kubectl rollout status deployment hello-world

kubectl get replicaset

kubectl rollout history  deployment hello-world
  deployment.apps/hello-world 
  REVISION  CHANGE-CAUSE
    1         kubectl apply --filename=deployment.probes-1.yaml --record=true
    2         kubectl apply --filename=deployment.probes-2.yaml --record=true

kubectl rollout history  deployment hello-world --revision=1
kubectl rollout history  deployment hello-world --revision=2

kubectl rollout undo deployment hello-world --to-revision=2

Let's restart deployment

kubectl rollout restart deployment hello-world
kubectl describe deployment hello-world
### clean test
kubectl delete deployment hello-world 
kubectl delete service hello-world

Scaling Deployment

kubectl scale deployment hello-world --replicas=10

kubectl apply -f deployment.yaml

Introducing Daemonset

Ensures that all or some Nodes run Pod
Effectively an init daemon inside your cluster
Example workloads
Kube-proxy for network services
Log cpllection
Metrics services
Resource monitoring agents
storage daemons

apiVersion: apps/v1
kind: DaemonSet
metadata:
  labels:
    app: hello-world-app
  name: hello-world-ds
spec:
  selector:
    matchLabels:
      app: hello-world-app   #Match
  template:
    metadata:
      labels:
        app: hello-world-app
    spec:
      nodeSelector:
        node: hello-world-ns
      containers:
      - name: hello-wold
        image: gcr.io/google-samples/hello-app:1.0

DaemonSet Update strategy

RollingUpdate
onDelete

Creating a DaemonSet

kubectl get daemonsets --namespace kube-system kube-proxy

kubectl apply -f DaemonSet.yaml

kubectl get daemonsets

kubectl get daemonsets -o wide

kubectl describe daemonset hello-world  | more

#### no Selector

apiVersion: apps/v1
kind: DaemonSet
metadata:
  labels:
    app: hello-world-app
  name: hello-world-ds
spec:
  selector:
    matchLabels:
      app: hello-world-app   #Match
  template:
    metadata:
      labels:
        app: hello-world-app
    spec:
      # nodeSelector:
      #   node: hello-world-ns
      containers:
      - name: hello-wold
        image: gcr.io/google-samples/hello-app:1.0

Each Pods create with our label

kubectl get pods --show-labels

If we change the lable to one of our Pods

MYPOD=$(kubectl get pods -l app=hello-world-app | grep hello-world | head -n 1 | awk {'print $1'})
echo $MYPOD

kubectl label pods $MYPOD app=not-hello-world --overwrite

kubectl get pods --show-labels

We need a node that satisfies the Node Selector

kubectl label node worker1 node=hello-world-ns

What's going to happen if we remove the lable

kubectl label node worker1 node-

kubectl describe daemonsets hello-world-ds

kubectl delete daemonsets hello-world-ds

## Examine what our update stategy is ...default to rollingUpdate
kuecbtl get daemonSet hello-world -o yaml | more

Introducing jobs

Jobs create one or more Pods
Runs a program in a container to completion
Ensure that specified number of Pods complete successfully

Ensuring Jobs Run to completion

Interrupted Execution
None-zero Exit code
Rescheduled
restartPolicy
NoteJobs: Lifecycle

apiVersion: batch/v1
kind: Job
metadata:
  name: hello-world
spec:
  template:
    spec:
      containers:
      - name: ubuntu
        image: ubuntu
        command:
         - /bin/bash
         - "-c"
         - "/bin/echo Hello from Pod $(hostname) at $(date)"
      restartPolicy: Never

Controlling Job Execution

backoffLimit - number of Job retries
before it's marked failed
activeDeadlineSeconds - max execution time for the job
parallelism - max number of running pods in a Job at a point in time
completions - number of Pods that need to finish successfully

Introducing Cronjobs

CronJob will run a Job on a given time based schedule
Conceptually similar to UNIX/LINUX cron Job
CronJob resource is created when the object is submitted to the Api server

Controlling CronJobs Execution

schedule - a cron formatted schedule
suspend -suspends the CronJob
startingDeadlineSeconds the Job hasn't started in this amount of time mark it as failed
concurrencyPolicy - handles concurrent executions of a job. Allow, Forbid or Replice

apiVersion: batch/v1
kind: CronJob
metadata:
  name: hello-world-cron
spec:
  schedule: "*1 * * * *"
  jobTemplate:
     spec:
       template:
          spec:
            containers:
            - name: ubuntu

Jobs

apiVersion: batch/v1
kind: Job
metadata:
  name: hello-world-job
spec:
  template:
    spec:
      containers:
      - name: ubuntu
        image: ubuntu
        command:
         - /bin/bash
         - "-c"
         - "/bin/echo Hello from Pod $(hostname) at $(date)"
      restartPolicy: Never

kubecl apply -f job.yaml
kubectl get job --watch
kubectl get pods
kubectl describe job hello-world-job

### Get the logs from stdout from the job Pod

kubectl get pods -l job-name=hello-world-job
kubectl logs hello-world-job-258rj

kubectl  delete job hello-world-job
kubectl get jobs

Job-failure-onfailure.yaml

apiVersion: batch/v1
kind: Job
metadata:
  name: hello-world-job
spec:
  backoffLimit: 2
  template:
    spec:
      containers:
      - name: ubuntu
        image: ubuntu
        command:
         - /bin/bash
         - "-c"
         - "/bin/echo Hello from Pod $(hostname) at $(date)"
      restartPolicy: Never

kubectl get pods --watch
kubectl get jobs

Demo 3 Defining a Parallel Job

kubectl apply -f paralleljob.yaml

apiVersion: batch/v1
kind: Job
metadata:
  name: hello-world-job
spec:
  completions: 50
  parallelism: 10
  template:
    spec:
      containers:
      - name: ubuntu
        image: ubuntu
        command:
         - /bin/bash
         - "-c"
         - "/bin/echo Hello from Pod $(hostname) at $(date)"
      restartPolicy: Never

kubectl get pods
watch 'kubectl describe job | head -n 11'
kubectl delete -f paralleljob.yaml

Demo 5 scheduling tasks with CronJobs

kubectl apply -f cronjob.yaml

Cronjob samole

apiVersion: batch/v1
kind: CronJob
metadata:
  name: hello-world-cron
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: ubuntu
            image: ubuntu
            command:
            - "/bin/bash"
            - "-c"
            - "/bin/echo Hello from Pod $(hostname) at $(date)"
          restartPolicy: Never

kubectl describe cronjobs | more
kubectl get pods --watch
kubectl get cronjob -o yaml

Statefulsets

Database workloads
Caching servers
Application state for web farms
Naming Storage Headless Service

Dry run

kubectl apply -f  deployment --dry-run=server
kubectl apply -f  deployment --dry-run=client
kubectl create deployment nginx --image=nginx --dry-run=client -o yaml > deployment.new.yaml

Working with kubectl diff

kubectl diff -f newdeployment.yaml
kubectl diff -f newdeployment.yaml | more

Api Discovery

#Get information anout our current cluster context
kubectl config get-contexts

### Change our context if needed by soecifying the Name
kubectl config use-context kubernetes-admin@kubernetes

kubectl cluster-info
#Get a list of Api
kubectl api-resources | more

# Using kubectl explain to see the structure of a resource..specifically

kubectl explain pods | more

Api Group

Pod
Node
namespace
PersistentVolume
PersistantVolumeClaim

Named Api Group

Apps - Deployment
Storage.k8s.io - StorageClass
rbac.authorization.k8s.io - Role

Api Version

Api is versioned
Provide stability for existing implementions
Enable forward change

Alpha - Beta -> Stable

No direct relation to release version

kubectl api-resources |more

kubectl api-resources --api-group=apps

kubectl explain deployment --api-version=apps/v1 | more

kubectl api-versions | sort | more

Core API (Legacy)

http://apiserver:port/api/$VERSION/$RESOURCE_TYPE
http://apiserver:port/api/$VERSION/$NAMESPACE/$RESOURCE_TYPE/$RESOURCE_NAME

API Group

http://apiserver:port/api/$GROUPNAME/$VERSION/namespaces/$NAMESPACE/$RESOURCE_TYPE/$RESOURCE_NAME

Conaction-->Authentication-->Authorization-->Admission Control

# we can use the -v option to increse the verbosity of out request
kubectl get pod hello-world-64cfbbd96c-44ls6 -v 6
#####################
kubectl get pod hello-world-64cfbbd96c-44ls6 -v 7
I1014 13:19:52.627860  797543 loader.go:395] Config loaded from file:  /etc/kubernetes/admin.conf
I1014 13:19:52.632851  797543 round_trippers.go:463] GET https://172.20.45.20:6443/api/v1/namespaces/default/pods/hello-world-64cfbbd96c-44ls6
I1014 13:19:52.632968  797543 round_trippers.go:469] Request Headers:
I1014 13:19:52.633099  797543 round_trippers.go:473]     Accept: application/json;as=Table;v=v1;g=meta.k8s.io,application/json;as=Table;v=v1beta1;g=meta.k8s.io,application/json
I1014 13:19:52.633236  797543 round_trippers.go:473]     User-Agent: kubectl/v1.30.5 (linux/amd64) kubernetes/74e84a9
I1014 13:19:52.641417  797543 round_trippers.go:574] Response Status: 200 OK in 8 milliseconds
NAME                           READY   STATUS    RESTARTS   AGE
hello-world-64cfbbd96c-44ls6   1/1     Running   0          97s

Start up a kubectl proxy session, This will authenticate use to the API server

kubectl proxy &

curl http://localhost:8001/api/v1/namespaces/default/pods/hello-world | head -n 20

kubectl get pods --watch -v 6

Organizing Object in Kubernetes

namespace
Labels
Annotations

apiVersion: v1
kind: Namespace
metadata:
  name: playgroundinyaml
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-world
  labels:
    app: hello-world
  namespace: playgroundinyaml
spec:
  replicas: 4
  selector:
    matchLables:
      app: hello-world
  template:
    metadata:
      labels:
        app: hello-world-app
    spec:
      # nodeSelector:
      #   node: hello-world-ns
      containers:
      - name: hello-wold
        image: gcr.io/google-samples/hello-app:1.0

kubectl get namespces

kubectl api-resources --namespaces=true |head
kubectl api-resource --namespaces=false | head

kubectl describe namespaces

kubectl get pods --all-namespaces

kubectl get all --all-namespaces

kubectl create namespace playgroupd1

kubectl get pods -n playgroupd1

kubectl delete pods -all --namespace playgroupd1

Labels

Used to organize resource - Pods,Nodes and more
Lables Selector are used to select/query Objects
Creating resource with Labels

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
  labels:
    app: v1
    tier: PROD
spec:
  ...

kubectl label pod nginx tier=PROD app=v1
kubectl label pod nginx tier=DEBUG app=v1 --overwrite
kuebctl label pod nignx app-

kubectl get pods --show-labels
kubectl get pods --selector tier=Prod
kubectl get pods -l 'tier in (prod,qa)'
kubectl get pods -l 'tier notin (prod,qa)'

Controller and Services match pods using selector
Scheduling to specific Nodes
Special hardware (SSD or GPU)

kind: Deployment
...
spec:
 selector:
   matchLabels:
     run: hello-world ## mache
...
  template:
    metadata:
      labels:
        run: hello-world ## mache
    spec:
      contaners:
---

kind: Service
...
spec:
  selector:
    run: hello-world ## mache
  ports:
  - port: 80
    protocol: TCP
    targetPort: 8080

Name		Name	Last commit message	Last commit date
Latest commit History 417 Commits
.github		.github
ELK		ELK
LXC_LXD		LXC_LXD
alert_manager_glusterfs_automount		alert_manager_glusterfs_automount
alpine		alpine
ansible_custome		ansible_custome
awk		awk
aws		aws
bash		bash
cicd		cicd
create_repository		create_repository
databases		databases
disk		disk
dns		dns
docker		docker
filim		filim
freebsd		freebsd
gafana_dashboard		gafana_dashboard
git		git
go		go
google-authenticator		google-authenticator
hackerrank		hackerrank
haproxy for wordpress		haproxy for wordpress
haproxy		haproxy
health_check_opensatck		health_check_opensatck
helmchart		helmchart
kernel		kernel
kubernetes		kubernetes
learning terraform		learning terraform
linux_command		linux_command
loki		loki
makefile		makefile
monito_linux _performance		monito_linux _performance
mysql		mysql
namespace		namespace
netbox		netbox
network		network
nginx		nginx
nixos		nixos
ntp_server		ntp_server
opensatck/araz_cloud		opensatck/araz_cloud
openstack		openstack
openvpn		openvpn
ping2/code		ping2/code
programmer		programmer
prometheus		prometheus
regex		regex
repair_boot		repair_boot
sdn		sdn
squid		squid
ssh		ssh
storage		storage
tmux		tmux
tunning_os		tunning_os
vagrant		vagrant
vaja		vaja
vim		vim
wordpress		wordpress
yubikey		yubikey
README.md		README.md
bootloader		bootloader
command_automation_ssh		command_automation_ssh
configuration_keepalived.txt		configuration_keepalived.txt
connect_harbor_keycloak.md		connect_harbor_keycloak.md
crontab-debugging.md		crontab-debugging.md
dd.txt		dd.txt
ffmpeg.md		ffmpeg.md
find.txt		find.txt
hetzner-rescue.md		hetzner-rescue.md
journal_log_routate		journal_log_routate
keycloak.md		keycloak.md
lxc_destory.txt		lxc_destory.txt
pips_linux.txt		pips_linux.txt
second_monitor		second_monitor
systemd		systemd
userdata		userdata
vim.txt		vim.txt

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