7/6 Kubernetes 설치 및 Cluster 만들기 실습

클러스터 : 여러개의 오브젝트를 하나로 묶은것

클러스터링 : 클러스터를 하는것

시스템 클러스터 : 시스템을 하나로 묶어주는것

*방식 2가지

hp(high performance): 여러개의 시스템을 묶어서 고성능의 성능을 내는것. 대용량의 작업을 여러개의 시스템이 하는것. 슈퍼컴퓨터가 그 예시

ha(high availiability): 고 가용성

 

---

 

웹서버와 웹어플리케이션서버 구분할 줄 알아야함

*Web Browser

- html, css, js, picture (client side)-> 얘네를 렌더링 하는것, 보기좋게 비쥬얼라이징 해줌

 

*Web Server 정적(static) 인 컨텐츠 -> 같은것만 보여줌

-apache

-nginx

-IIS

- html, css, js, pictures

 

*Web Application Server(WAS): 어플리케이션 서버는 앱을 실행시키는 역할, 동적인 컨텐츠

-tomcat(WAS의 기능에 부합하지 않음: web container)

-Web logic

-Web Sphere

...

-apache/nginx + module

 

(server side)

-JSP/Sevlet

-Python(Django, Flask)

-Ruby(Ruby on Rails)

-.net(ASP.net) - ASP

-node.js(javascript)

...

 

https://roadmap.sh/

Developer Roadmaps

 

https://landscape.cncf.io/

 

CNCF Cloud Native Interactive Landscape

 

노드는 컨테이너를 실행하는 컨테이너 시스템

 

https://kubernetes.io/docs/concepts/overview/components/

Kubernetes Components

 

https://github.com/kelseyhightower/kubernetes-the-hard-way

kelseyhightower/kubernetes-the-hard-way

https://kubernetes.io/ko/docs/setup/production-environment/tools/kubeadm/install-kubeadm/

kubeadm 설치하기

---

cd vagrant/

mkdir k8s

cd k8s

code Vagrantfile

vagrant up

 

# -*- mode: ruby -*-
# vi: set ft=ruby :

Vagrant.configure("2") do |config|
    config.vm.define "k-control" do |ubuntu|
        ubuntu.vm.box = "ubuntu/focal64"
        ubuntu.vm.hostname = "k-control" 
        ubuntu.vm.network "private_network", ip: "192.168.200.50"
        ubuntu.vm.provider "virtualbox" do |vb|
            vb.name = "k-control"
            vb.cpus = 2
            vb.memory = 3000
        end
    end
    config.vm.define "k-node1" do |ubuntu|
        ubuntu.vm.box = "ubuntu/focal64"
        ubuntu.vm.hostname = "k-node1" 
        ubuntu.vm.network "private_network", ip: "192.168.200.51"
        ubuntu.vm.provider "virtualbox" do |vb|
            vb.name = "k-node1"
            vb.cpus = 2
            vb.memory = 3000
        end
    end
    config.vm.define "k-node2" do |ubuntu|
        ubuntu.vm.box = "ubuntu/focal64"
        ubuntu.vm.hostname = "k-node2" 
        ubuntu.vm.network "private_network", ip: "192.168.200.52"
        ubuntu.vm.provider "virtualbox" do |vb|
            vb.name = "k-node2"
            vb.cpus = 2
            vb.memory = 3000
        end
    end
    config.vm.define "k-node3" do |ubuntu|
        ubuntu.vm.box = "ubuntu/focal64"
        ubuntu.vm.hostname = "k-node3" 
        ubuntu.vm.network "private_network", ip: "192.168.200.53"
        ubuntu.vm.provider "virtualbox" do |vb|
            vb.name = "k-node3"
            vb.cpus = 2
            vb.memory = 3000
        end
    end
end

 

 

 

(설치 참고: https://docs.docker.com/engine/install/ubuntu/)

sudo apt-get remove docker docker-engine docker.io containerd runc
sudo apt-get update

sudo apt-get install \
    apt-transport-https \
    ca-certificates \
    curl \
    gnupg \
    lsb-release
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
echo \
  "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update
sudo apt-get install docker-ce docker-ce-cli containerd.io

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*kubeadm, kubelet 및 kubectl 설치(k-control, k-node1...각각 들어가서 설치)
(설치 참고: https://kubernetes.io/ko/docs/setup/production-environment/tools/kubeadm/install-kubeadm/)

sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates curl
sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://packages.cloud.google.com/apt/doc/apt-key.gpg
echo "deb [signed-by=/usr/share/keyrings/kubernetes-archive-keyring.gpg] https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

 

* k-control
(https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/)


sudo kubeadm init --control-plane-endpoint 192.168.200.50 --pod-network-cidr 192.168.0.0/16 --apiserver-advertise-address 192.168.200.50
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
ls -l ~/.kube/config
-rw------- 1 vagrant vagrant 5594 Jul  6 06:44 /home/vagrant/.kube/config



(https://docs.projectcalico.org/getting-started/kubernetes/self-managed-onprem/onpremises)

kubectl apply -f https://docs.projectcalico.org/manifests/calico.yaml
kubectl get nodes     -> ready 상태인지 확인
kubeadm token list
TOKEN                     TTL         EXPIRES                USAGES                   DESCRIPTION                                                EXTRA GROUPS
bkoyxl.3aht0jk9ws0d4nfj   23h         2021-07-07T06:42:57Z   authentication,signing   The default bootstrap token generated by 'kubeadm init'.   system:bootstrappers:kubeadm:default-node-token

openssl x509 -pubkey -in /etc/kubernetes/pki/ca.crt | openssl rsa -pubin -outform der 2>/dev/null | \
>    openssl dgst -sha256 -hex | sed 's/^.* //'
015ac96083dbcdeece03ff30344df57cf26c0785570975dbeece3c90f0eff824


*k-node123 가서 명령어 입력
(ubeadm join --token <token> <control-plane-host>:<control-plane-port> --discovery-token-ca-cert-hash sha256:<hash>)
sudo kubeadm join 192.168.200.50:6443 --token bkoyxl.3aht0jk9ws0d4nfj --discovery-token-ca-cert-hash sha256:015ac96083dbcdeece03ff30344df57cf26c0785570975dbeece3c90f0eff824 

*다시 k-control 가서 노드 확인
kubectl get nodes

*cka (쿠버네티스 자격증)->설치 업그레이드 할줄알아야함 안그러면 빵점

sudo apt-cache madison kubeadm

sudo apt install kubeadm=1.18.19-00 kubectl=1.18.19-00 kubelet=1.18.19-00

 

*sudo kubeadm reset

*리셋말고 vagrant destroy -f 해서 다시 설치

sudo apt install kubeadm=1.18.19-00 kubectl=1.18.19-00 kubelet=1.18.19-00

 

 

*노드 확인시 계속 not ready 상태일 경우 k-control, k-node123 전부 이대로 pull 해주기

sudo docker login
sudo docker pull calico/node:v3.19.1
sudo docker pull calico/pod2daemon-flexvol:v3.19.1
sudo docker pull calico/cni:v3.19.1
sudo docker pull calico/kube-controllers:v3.19.1
kubectl get nodes             -> k-control 에서 확인