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[kubernetes] kubespray를 이용한 kubernetes 클러스터 배포

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kubespray를 이용한 kubernetes 클러스터 배포

릴리스 히스토리

쿠버네티스 프로젝트는 가장 최신의 3개 마이너(minor) 릴리스(1.25, 1.24, 1.23)에 대해서 릴리스 브랜치를 관리한다. 쿠버네티스 1.19 및 이후 신규 버전은 약 1년간 패치 지원을 받을 수 있다. 쿠버네티스 1.18 및 이전 버전은 약 9개월간의 패치 지원을 받을 수 있다.

쿠버네티스 버전은 x.y.z 의 형태로 표현되는데, x 는 메이저(major) 버전, y 는 마이너(minor), z 는 패치(patch) 버전을 의미하며, 이는 시맨틱(semantic) 버전의 용어를 따른 것이다.

https://kubernetes.io/ko/releases/

버전 차이 정책(Version Skew Policy)

- https://kubernetes.io/releases/version-skew-policy/

배포 도구로 쿠버네티스 설치하기
https://kubernetes.io/ko/docs/setup/production-environment/tools/

Kubernetes The Hard Way - https://github.com/kelseyhightower/kubernetes-the-hard-way

kubeadm - https://github.com/kubernetes/kubeadm
kubespary(kubeadm + ansible) - https://github.com/kubespray
minikube - https://github.com/kubernetes/minikube, https://minikube.sigs.k8s.io/docs/start/
kops - https://github.com/kubernetes/kops

테스트 환경

$ cat /proc/cpuinfo | egrep 'model name' | head -n1
model name	: Intel(R) Xeon(R) CPU E5-2690 v4 @ 2.60GHz

$ free -h
              total        used        free      shared  buff/cache   available
Mem:           27Gi        10Gi       6.9Gi        13Mi       9.8Gi        16Gi
Swap:         2.0Gi       1.0Mi       2.0Gi

$ df -h | egrep -v 'tmpfs|loop'
Filesystem      Size  Used Avail Use% Mounted on
udev             14G     0   14G   0% /dev
/dev/vda5       196G   24G  163G  13% /
/dev/vda1       511M  4.0K  511M   1% /boot/efi

서버 구성 현황

호스트명 IP 역할 CPU Memory 비고
kube-control1 192.168.56.11 Control Plane 4 4096  
kube-node1 192.168.56.21 Node 2 4096  
kube-node2 192.168.56.22 Node 2 4096  
kube-node3 192.168.56.23 Node 2 4096  

사전 작업

1. swap 메모리 비활성화

swapoff -a
sed -i 's/.*swap.*/#&/' /etc/fstab

2. ip forward 설정 및 확인

echo 1 > /proc/sys/net/ipv4/ip_forward
$ cat /proc/sys/net/ipv4/ip_forward
1
cat > /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1 
net.bridge.bridge-nf-call-iptables = 1
EOF
sysctl --system

kubespray 설치

Control Plane 작업

ssh 키 생성 및 복사(계정 정보 : vagrant / vagrant)

ssh-keygen -f ~/.ssh/id_rsa -N ''
$ ssh-keygen -f ~/.ssh/id_rsa -N ''
Generating public/private rsa key pair.
Your identification has been saved in /home/vagrant/.ssh/id_rsa
Your public key has been saved in /home/vagrant/.ssh/id_rsa.pub
The key fingerprint is:
SHA256:6wHWOUrODYmeMAZJLNJk2FnOJd0R0ueiY+tkFBpBk8s vagrant@kube-control1
The key's randomart image is:
+---[RSA 3072]----+
|.*o+*ooooo       |
|=++o.=..o .      |
|=  .+..  o       |
| .  E+ +...      |
|  + o B.S.       |
| . + B+= o       |
|    o.*o+        |
|     o.. .       |
|     .. .        |
+----[SHA256]-----+
ssh-copy-id vagrant@192.168.56.11
ssh-copy-id vagrant@192.168.56.21
$ ssh-copy-id vagrant@192.168.56.21
/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/home/vagrant/.ssh/id_rsa.pub"
The authenticity of host '192.168.56.21 (192.168.56.21)' can't be established.
ECDSA key fingerprint is SHA256:QLk+YEc2ZU1qNye9PcvqL9B33bemsEU1VSmycNLmx6s.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed
/usr/bin/ssh-copy-id: INFO: 1 key(s) remain to be installed -- if you are prompted now it is to install the new keys
vagrant@192.168.56.21's password:

Number of key(s) added: 1

Now try logging into the machine, with:   "ssh 'vagrant@192.168.56.21'"
and check to make sure that only the key(s) you wanted were added.
ssh-copy-id vagrant@192.168.56.22
ssh-copy-id vagrant@192.168.56.23
sudo timedatectl set-timezone Asia/Seoul

python3, pip, git 설치

sudo apt update
sudo apt install -y python3 python3-pip git vim

kubespray 설치

cd ~

kubespray git 저장소 클론(최신 릴리즈)

git clone --single-branch --branch v2.19.1 https://github.com/kubernetes-sigs/kubespray.git
cd kubespray

의존성 확인 및 설치

$ cat requirements.txt
ansible==5.7.1
ansible-core==2.12.5
cryptography==3.4.8
jinja2==2.11.3
netaddr==0.7.19
pbr==5.4.4
jmespath==0.9.5
ruamel.yaml==0.16.10
ruamel.yaml.clib==0.2.6
MarkupSafe==1.1.1
sudo pip3 install -r requirements.txt
$ sudo pip3 install -r requirements.txt
Collecting ansible==5.7.1
  Downloading ansible-5.7.1.tar.gz (35.7 MB)
     |████████████████████████████████| 35.7 MB 1.6 kB/s
Collecting ansible-core==2.12.5
  Downloading ansible-core-2.12.5.tar.gz (7.8 MB)
     |████████████████████████████████| 7.8 MB 13 kB/s
...

인벤토리 생성(sample 사용)

cp -rfp inventory/sample inventory/mycluster

inventory.ini 편집

vim inventory/mycluster/inventory.ini
[all]
kube-control1	ansible_host=192.168.56.11 ip=192.168.56.11
kube-node1	ansible_host=192.168.56.21 ip=192.168.56.21
kube-node2	ansible_host=192.168.56.22 ip=192.168.56.22
kube-node3	ansible_host=192.168.56.23 ip=192.168.56.23

[kube_control_plane]
kube-control1

[etcd]
kube-control1

[kube_node]
kube-node1
kube-node2
kube-node3

[calico_rr]

[k8s_cluster:children]
kube_control_plane
kube_node
calico_rr

addons.yml 편집(파라미터 확인 및 변경)

vim inventory/mycluster/group_vars/k8s_cluster/addons.yml
metrics_server_enabled: true
ingress_nginx_enabled: true
metallb_enabled: true
metallb_ip_range:
  - "192.168.56.200-192.168.56.209"
metallb_protocol: "layer2"

k8s-cluster.yml 편집(파라미터 확인 및 변경)

vim inventory/mycluster/group_vars/k8s_cluster/k8s-cluster.yml
kube_proxy_strict_arp: true
container_manager: docker

ansible 통신 확인

ansible all -i inventory/mycluster/inventory.ini -m ping
$ ansible all -i inventory/mycluster/inventory.ini -m ping
[WARNING]: Skipping callback plugin 'ara_default', unable to load
kube-node3 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
kube-node2 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
kube-node1 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
kube-control1 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}

apt 캐시 업데이트(모든 노드)

ansible all -i inventory/mycluster/inventory.ini -m apt -a 'update_cache=yes' --become
$ ansible all -i inventory/mycluster/inventory.ini -m apt -a 'update_cache=yes' --become
[WARNING]: Skipping callback plugin 'ara_default', unable to load
kube-control1 | CHANGED => {
    "cache_update_time": 1663594656,
    "cache_updated": true,
    "changed": true
}
kube-node3 | CHANGED => {
    "cache_update_time": 1663594662,
    "cache_updated": true,
    "changed": true
}
kube-node1 | CHANGED => {
    "cache_update_time": 1663594663,
    "cache_updated": true,
    "changed": true
}
kube-node2 | CHANGED => {
    "cache_update_time": 1663594662,
    "cache_updated": true,
    "changed": true
}

timezone 설정 및 time, timezone 확인

ansible all -i inventory/mycluster/inventory.ini -a 'sudo timedatectl set-timezone Asia/Seoul' --become
$ ansible all -i inventory/mycluster/inventory.ini -a 'sudo timedatectl set-timezone Asia/Seoul' --become
[WARNING]: Skipping callback plugin 'ara_default', unable to load
kube-node1 | CHANGED | rc=0 >>

kube-node3 | CHANGED | rc=0 >>

kube-node2 | CHANGED | rc=0 >>

kube-control1 | CHANGED | rc=0 >>
ansible all -i inventory/mycluster/inventory.ini -a 'date'
$ ansible all -i inventory/mycluster/inventory.ini -a 'date'
[WARNING]: Skipping callback plugin 'ara_default', unable to load
kube-control1 | CHANGED | rc=0 >>
Mon Sep 19 22:43:04 KST 2022
kube-node3 | CHANGED | rc=0 >>
Mon Sep 19 22:43:04 KST 2022
kube-node2 | CHANGED | rc=0 >>
Mon Sep 19 22:43:04 KST 2022
kube-node1 | CHANGED | rc=0 >>
Mon Sep 19 22:43:04 KST 2022
ansible all -i inventory/mycluster/inventory.ini -a 'timedatectl'
$ ansible all -i inventory/mycluster/inventory.ini -a 'timedatectl'
[WARNING]: Skipping callback plugin 'ara_default', unable to load
kube-node2 | CHANGED | rc=0 >>
               Local time: Mon 2022-09-19 22:44:55 KST
           Universal time: Mon 2022-09-19 13:44:55 UTC
                 RTC time: Mon 2022-09-19 13:44:53
                Time zone: Asia/Seoul (KST, +0900)
System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no
kube-node3 | CHANGED | rc=0 >>
               Local time: Mon 2022-09-19 22:44:55 KST
           Universal time: Mon 2022-09-19 13:44:55 UTC
                 RTC time: Mon 2022-09-19 13:44:53
                Time zone: Asia/Seoul (KST, +0900)
System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no
kube-node1 | CHANGED | rc=0 >>
               Local time: Mon 2022-09-19 22:44:55 KST
           Universal time: Mon 2022-09-19 13:44:55 UTC
                 RTC time: Mon 2022-09-19 13:44:54
                Time zone: Asia/Seoul (KST, +0900)
System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no
kube-control1 | CHANGED | rc=0 >>
               Local time: Mon 2022-09-19 22:44:55 KST
           Universal time: Mon 2022-09-19 13:44:55 UTC
                 RTC time: Mon 2022-09-19 13:44:53
                Time zone: Asia/Seoul (KST, +0900)
System clock synchronized: no
              NTP service: inactive
          RTC in local TZ: no

ansible 플레이북 실행(kubernetes v1.22.10 설치)

ansible-playbook -i inventory/mycluster/inventory.ini cluster.yml -e kube_version=v1.22.10 --become

자격증명 가져오기

mkdir ~/.kube
sudo cp /etc/kubernetes/admin.conf ~/.kube/config
sudo chown $USER:$USER ~/.kube/config

kubectl 명령 자동 완성

kubectl completion bash | sudo tee /etc/bash_completion.d/kubectl
echo 'source <(kubectl completion bash)' >>~/.bashrc
exec bash

kubernetes 클러스터 확인

kubectl get nodes
$ kubectl get nodes
NAME            STATUS   ROLES                  AGE   VERSION
kube-control1   Ready    control-plane,master   70m   v1.22.10
kube-node1      Ready    <none>                 67m   v1.22.10
kube-node2      Ready    <none>                 67m   v1.22.10
kube-node3      Ready    <none>                 67m   v1.22.10
kubectl api-versions
$ kubectl api-versions
admissionregistration.k8s.io/v1
apiextensions.k8s.io/v1
apiregistration.k8s.io/v1
apps/v1
authentication.k8s.io/v1
authorization.k8s.io/v1
autoscaling/v1
autoscaling/v2beta1
autoscaling/v2beta2
batch/v1
batch/v1beta1
certificates.k8s.io/v1
coordination.k8s.io/v1
crd.projectcalico.org/v1
discovery.k8s.io/v1
discovery.k8s.io/v1beta1
events.k8s.io/v1
events.k8s.io/v1beta1
flowcontrol.apiserver.k8s.io/v1beta1
metrics.k8s.io/v1beta1
networking.k8s.io/v1
node.k8s.io/v1
node.k8s.io/v1beta1
policy/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
scheduling.k8s.io/v1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1
kubectl get pods -A

kubectl api-resources

 

참고URL

- [리눅스] vagrant 패키지 설치 및 ubuntu 배포 : https://scbyun.com/1322

- kubectl 자동 완성 활성화 : https://kubernetes.io/docs/tasks/tools/included/optional-kubectl-configs-bash-linux

 

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