[kubernetes] 쿠버네티스 설치 및 설정

kubernetes cluster install tools

google kubernetes engine (GKE)

• create account on GKE
• add method of payment
• intall and use gcloud - Vendor-specific command to manage GKE
• https://console.cloud.google.com/getting-started

$ gcloud container clusters create xxxx
$ gcloud container clusters list
$ kubectl get nodes
$ gcloud container clusters delete xxxx

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Minikube

• open source project within Github kubernetes
• download from google
• assumes VirtualBox already installed
• useful for developers
• uses Go binary localkube
• Also uses Docker

$ curl -Lo minikube https://storage.googleapis.com/minikube/releases/latest/minikube-darwin-amd64
$ chmod +x minikube
$ sudo mv minikube /usr/local/bin
$ minikube start
$ kubectl get nodes

 

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kubespray

https://github.com/kubernetes-incubator/kubespray

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kubernetes operations (kops)

• AWS 지원, GKE beta, VMWare alpha

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kubeadm

• available since kubernetes 1.4.0
• works with ubuntu 16.04 and cent os 7.1
• main-step
  - Run kubeadm init on the head node
  - Create a network for IP-per-Pod criteria
  - Run kubeadm join on worker or secondary master nodes
• documentation
  https://kubernetes.io/docs/setup/independent/create-cluster-kubeadm/
• install A Pod Network
  1) Only one pod network per per cluster
  2) Several to choose from
  - Calico : projectcalico.org
  - Canal
  - Flannel : github.com/coreos/flannel
  - Kube-router : github.com/cloudnativelabs/kube-router
  - Romana : github.com/romana/romana
  - Weave Net : weave.works/oss/net
  $ kubectl create -f https://git.io./weave-kube
  3) Can become complicated to manage
  4) Several add-ons available

 

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kubectl 설치

• install or compile kubectl
• main binary for working with objects
• available for common distributions via dedicated repos
• configuration file : ~/.kube/config
  - endpoints
  - SSL keys
  - contexts

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설치시 고려 사항

• Which provider should I use?
  Public or private cloud?
  
• Which operating system should I use?
• Which networking solution should I use?
  Do I need an overlay?
• Where should I run my etcd cluster?
  3 node 형태로 많이 쓰임
  
• Should I configure Highly-Available head nodes (master node)?
  고가용성 3가지
  - 서비스 자체 관점의 H/A
  - master 노드의 H/A (api-server, controller, scheduler..)
  - DB (ETCD) H/A

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주요 구성 설정들

• single-node
• Single head node(master node), multiple workers
• Multiple head nodes with HA, multiple workers
• HA etcd, HA head nodes, multiple workers
• Federation(multi cloud) also provides higher availablility

 

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kubernetes를 위한 systemd unit file

• https://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/

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Hyperkube 사용한 설치

• 각 이미지를 실행하여 master를 설치 할 수 있다.

$ docker run --rm gcr.io/google_containers/hyperkube:v1.10.12 /hyperkube apiserver --help
$ docker run --rm gcr.io/google_containers/hyperkube:v1.10.12 /hyperkube scheduler --help
$ docker run --rm gcr.io/google_containers/hyperkube:v1.10.12 /hyperkube controller-manager --help

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source 로 부터 직접 컴파일

• Configure Golang environment
• Clone source code
• May need to install other compiler and libraries

 

 

참조) CKA 대비 간단 실습

01. kubeadm 을 이용한 설치 및 세팅
02. kubernetes 클러스터 노드 확장 및 셋팅
03. 간단한 application 배포, yaml템플릿, 서비스 expose 해보기
04. deployment 의 CPU, Memory 제약
05. namespace 를 위한 resource limit 설정
06. 좀더 복잡한 deployment 배포해보기
07. 기본 Node 의 maintenance (유지보수)
08. API AND ACCESS
09. API 객체
10. Managing State with Deployments
11. Service Resource
12. Volumes and Data : ConfigMap 간단 테스트
13. PV 와 PVC 생성
14. ResourceQuota 사용 (PVC Count 와 Usage를 제한)
15. ingress 간단 실습
16. Scheduling - label 사용한 pod 할당
17. Scheduling - Taint를 이용한 pod 배포 관리
18. 로깅과 트러블슈팅 : 로그위치와 로그 출력 보기
19. 로깅과 트러블슈팅 : Metrics와 DashBoard
20. CRD (Custom Resource Definition)
21. helm
22. Security - TLS
23. Security - Authentication, Authorization, Admission
24. HA(High Availability) 구성 - master node