ubuntu 20.04 K8s 설치 노트

OpenStack에서 Ubuntu 20.04위에 Multi-cluster k8s설치 기록입니다

 

1. 도커 설치 

sudo apt-get update
 
sudo apt-get install \
    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=$(dpkg --print-architecture) 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

sudo systemctl enable docker
sudo systemctl start docker

 

1.1 설치 이후 containerd설정파일을 수정

vim /etc/containerd/config.toml

이부분을 주석처리 해준다
#disable_plugins = ["cri"]

containerd 재시작

systemctl stop containerd
systemctl start containerd

 

2. K8s 설치

#swap영역을 꺼준다
swapoff -a && sed -i '/swap/s/^/#/' /etc/fstab

#ubuntu 20.04에서는 기본적으로 keyrings폴더가 없어서 다르게 설정함
sudo curl -fsSLo /usr/share/keyrings/kubernetes-archive-keyring.gpg https://dl.k8s.io/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 -y

#k8s 설치 및 버전 홀드 명령어
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

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

 export KUBECONFIG=/etc/kubernetes/admin.conf

 

3. K8s control-plane 설정

 

sudo kubeadm init --control-plane-endpoint [controlplane IP]:6443 --upload-certs

#이후 다음과같은 URL들이 생성됨

kubeadm join 10.10.10.46:6443 --token ygmu0q.07f8v7xz3ghq6k1t \
	--discovery-token-ca-cert-hash sha256:f16a98dbc6fedbe229f57ba2c8bf531623be8ca8d0f536afb3e363a3ca14f527 \
	--control-plane --certificate-key 3964d2b0dc528a3c2000d51383aa2825197305d31ab935a92069741628e1ca8d
#위 URL은 join할 control-plane node에서 실행해 주면 됨

kubeadm join 10.10.10.46:6443 --token nf8qv9.g3iu91lv102w17yt --discovery-token-ca-cert-hash sha256:f16a98dbc6fedbe229f57ba2c8bf531623be8ca8d0f536afb3e363a3ca14f527
#위 URL은 join할 worker-node 에서 실행해 주면 됨

 

만약 url을 잃어버렸을경우 재 발급 방법

#일반 node join문 재 출력 명령어
kubeadm token create --print-join-command

#Control-plane join문 재 출력 
echo $(kubeadm token create --print-join-command) --control-plane --certificate-key $(kubeadm init phase upload-certs --upload-certs | grep -vw -e certificate -e Namespace)

 

4. Calico 설치

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

#시간좀 지난뒤 Pod 생성 및 구동 확인

kubectl get pods -A

NAMESPACE     NAME                                       READY   STATUS              RESTARTS      AGE
kube-system   calico-kube-controllers-7ddc4f45bc-vhsxq   0/1     ContainerCreating   0             17s
kube-system   calico-node-4rwvz                          0/1     Init:2/3            0             17s
kube-system   calico-node-v7x54                          0/1     Init:2/3            0             17s
kube-system   coredns-5dd5756b68-7q2vm                   0/1     ContainerCreating   0             19m
kube-system   coredns-5dd5756b68-vzr8g                   0/1     ContainerCreating   0             19m
kube-system   etcd-issac-master                          1/1     Running             1             19m
kube-system   etcd-issac-master3                         1/1     Running             0             18m
kube-system   kube-apiserver-issac-master                1/1     Running             1             19m
kube-system   kube-apiserver-issac-master3               1/1     Running             0             18m
kube-system   kube-controller-manager-issac-master       1/1     Running             1 (18m ago)   19m
kube-system   kube-controller-manager-issac-master3      1/1     Running             0             18m
kube-system   kube-proxy-6kd4x                           1/1     Running             0             18m
kube-system   kube-proxy-8f8h9                           1/1     Running             0             19m
kube-system   kube-scheduler-issac-master                1/1     Running             2 (18m ago)   19m

#k8s control-plane node ready상태 확인

kubectl get nodes

root@issac-master:/home/ubuntu# k get nodes
NAME            STATUS   ROLES           AGE   VERSION
issac-master    Ready    control-plane   20m   v1.28.2
issac-master3   Ready    control-plane   18m   v1.28.2