MBCDN

On all nodes

• Edit hostname
• Edit /etc/hosts file and add all nodes.
• Edit /etc/fstab and uncomment SWAP partition
• Edit /etc/initramfs-tools/conf.d/resume and uncomment swap uuid
• Find swap unit using systemctl –type swap and mask it using systemctl mask xxx.swap.

todo: what about fw, selinux?

apt update && apt install apt-transport-https curl

curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -

apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main"

apt update && apt install -y kubelet kubeadm kubectl docker.io

systemctl enable docker

Only on master node

kubeadm init --apiserver-advertise-address 192.168.0.100 --pod-network-cidr=172.16.0.0/16

# REMEMBER JOIN TOKEN output from last command !!!!!!!!!!!!!!!!!

# when done execute as regular user
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

# enable network addon
sudo kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml

Only on nodes except master

kubeadm join 192.168.0.100:6443 --token zbdvek.v8fnw7hw8xcdxk03 --discovery-token-ca-cert-hash sha256:724601e4cd00fd78312f1fbf3726b688e894fc88f2c25962f478e546a59929c7

API Token vergessen/abgelaufen?

kubeadm token create --print-join-command

Test on master node

kubectl run my-httpd --image=httpd --port=80
kubectl get pods -l app=demo
kubectl scale deployment [deployment] --replicas 3
kubectl exec -it my-httpd -- /bin/bash
kubectl set image deployment demo nginx=1.9.1
kubectl patch pod my-httpd --patch '{}'
kubectl delete pod myhttpd

Finally autostart

systemctl start kubelet
systemctl enable kubelet
systemctl start docker
systemctl start kubelet

apiVersion: v1
kind: Pod
metadata:
  name: demo
spec:
  containers:
  - image: nginx
    name: nginx
    imagePullPolicy: Always

kubectl create -f mypod.yml
kubectl delete pod demo

Update muss manuell vorgenommen werden (downtime).

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - name: nginx
        image: nginx
        imagePullPolicy: Always

kubectl create -f myreplica.yml
kubectl delete replicaset demo

Deployments nutzen intern replicaset und managen das rolling update von selbst.

apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: demo
  template:
    metadata:
      labels:
        app: demo
    spec:
      containers:
      - name: nginx
        image: nginx
        imagePullPolicy: Always
        env:
        - name: VERSION
          value: "v1"

kubectl create -f mydeployment.yml
kubectl delete deployment demo

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv0003
spec:
  capacity:
    storage: 5Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Recycle
  storageClassName: slow
  mountOptions:
    - hard
    - nfsvers=4.1
  nfs:
    path: /tmp
    server: 172.17.0.2

todo

• Host based
  • EmptyDir
  • HostPath
• Block Storage
  • Amazon EBS
  • GCE Persistent Disk
  • Azure Disk
  • vSphere Volume
  • …
• Distributed file system
  • NFS
  • Ceph
  • Gluster
  • Amazon EFS
  • Azure File System
  • …
• Other
  • Flocker
  • iSCSI
  • Git Repo
  • Quobyte
  • …

• Service types explained
• Full beginner course
• First steps after install
• Persistent volumes
• Kubectl secrets
• Ingress NginX
• The native web
• Networking
• Application deployment tutorial video todo
• Difference between deployment and replicaset
• K9s - Manage your Kubernetes Cluster with Style
• Die Rolle von HELM in Kubernetes