GitOps

[GunSik2]

GitOps

• 2017년에 개척된 Kubernetes 클러스터 관리 및 애플리케이션 제공을 수행하는 방법
• 클라우드 네이티브 애플리케이션 구축을 위한 운영 모델로, 다음 두 가지로 요약됨
  1. Kubernetes 및 기타 클라우드 네이티브 기술을 위한 운영 모델로, 컨테이너화된 클러스터 및 애플리케이션에 대한 Git 배포, 관리 및 모니터링을 통합하는 모범 사례 세트를 제공
  2. 애플리케이션 관리를 위한 개발자 경험으로 가는 길 종단 간 CICD 파이프라인과 Git 워크플로가 운영과 개발 모두에 적용
• GitOps의 원칙
  1. 전체 시스템을 선언적으로 정의
  2. 원하는 시스템 상태는 Git에서 버전 관리
  3. Git 변경 승인은 시스템에 자동으로 적용
  4. 소프트웨어 에이전트가 시스템의 정확성을 보장하고 경고
• 요약 모델

GitOps 개발자 환경

• Skaffold

참고자료

• GitOps 개념과 사례
• Weaveworks GitOps Core 오픈소스 툴
• GitOps template 사례
• GitOps Developer Toolkit. Part one: Skaffold

[GunSik2]

GitOps Quick Start

설치

curl -L "https://github.com/weaveworks/weave-gitops/releases/download/v0.3.0/gitops-$(uname)-$(uname -m)" -o gitops
chmod +x gitops
sudo mv ./gitops /usr/local/bin/gitops
gitops version

$ gitops install
$ kubectl get pods --namespace wego-system
NAME                                           READY   STATUS    RESTARTS   AGE
helm-controller-b5c45677f-zz6r7                1/1     Running   0          80s
image-automation-controller-57f8bf65c7-km8qn   1/1     Running   0          80s
image-reflector-controller-558c56b989-nnsbw    1/1     Running   0          80s
kustomize-controller-7fd4d6b4c8-jwbks          1/1     Running   0          80s
notification-controller-66545867f4-bsmqk       1/1     Running   0          80s
source-controller-5d469c75b6-vtjqf             1/1     Running   0          80s

GitHub에서 예시용 레퍼지토리 Fork

• https://github.com/wego-example/podinfo-deploy

GitOps 시험

1. GitOps 앱 등록

   
   $ git clone https://github.com/GunSik2/podinfo-deploy
   $ cd podinfo-deploy/
   $ ◎ Checking cluster status
   ✔ GitOps installed
   ⚠️ Setting the "GITHUB_TOKEN" environment variable to a valid token will allow ongoing use of the CLI without requiring a browser-based auth flow...

Visit this URL to authenticate with Github:

https://github.com/login/device

Type the following code into the page at the URL above: 735C-2CC2

Waiting for authentication flow completion...

Authentication successful!

Existing deploy key found Adding application:

Name: podinfo-deploy URL: ssh://git@github.com/GunSik2/podinfo-deploy.git Path: ./ Branch: main Type: kustomize

✚ Generating Source manifest ✚ Generating GitOps automation manifests ✚ Generating Application spec manifest ► Cloning ssh://git@github.com/GunSik2/podinfo-deploy.git Pull Request created: https://github.com/GunSik2/podinfo-deploy/pull/1

► Applying manifests to the cluster ► Committing and pushing gitops updates for application ✔ App is up to date

2. 중간에 Github 접속하여 인증 필요: https://github.com/login/device
![image](https://user-images.githubusercontent.com/11453229/135553089-0efe2f85-e9c1-4edb-86c3-90830e5c3c1a.png)

3. GitOps Pull Request 확인
![image](https://user-images.githubusercontent.com/11453229/135554836-bbf87246-f98a-414a-8474-145f5fd83641.png)

4. GitOps Pull Request 승인
![image](https://user-images.githubusercontent.com/11453229/135554890-220cc691-3dae-4b62-b497-535f0b46eef8.png)

5. App 배포 확인

$ kubectl get pod -n test NAME READY STATUS RESTARTS AGE backend-6597979bbf-njhtr 1/1 Running 0 2m frontend-745f795d57-dgbwx 1/1 Running 0 2m

$ gitops app status podinfo-deploy NAME READY MESSAGE REVISION SUSPENDED gitrepository/podinfo-deploy True Fetched revision: main/dfd72488c9be9ee52fd0726ba7e118dd7d84e48d main/dfd72488c9be9ee52fd0726ba7e118dd7d84e48d False

NAME READY MESSAGE REVISION SUSPENDED kustomization/podinfo-deploy True Applied revision: main/dfd72488c9be9ee52fd0726ba7e118dd7d84e48d main/dfd72488c9be9ee52fd0726ba7e118dd7d84e48d False

// 초기 배포 시 자동 생성된 파일 $ git pull $ tree .wego/ .wego/ ├── apps │   └── podinfo-deploy │   └── app.yaml └── targets └── local └── podinfo-deploy ├── podinfo-deploy-gitops-deploy.yaml └── podinfo-deploy-gitops-source.yaml

// Ingress 배포 (k8s v1.18은 ingress CLI 배포 미 지원) // $ kubectl create ingress podinfo --rule="podinfo.test.14.xx.xx.xx.xip.io/*=frontend:9898" -n test $ vi ingress.yml

apiVersion: networking.k8s.io/v1beta1 kind: Ingress metadata: name: podinfo namespace: test spec: rules:

• host: podinfo.14.xxx.xxx.xxx.xip.io http: paths:

  • backend: serviceName: frontend servicePort: 9898

    
    7. 앱 접속 확인
    ![image](https://user-images.githubusercontent.com/11453229/135608506-bea75137-8bb9-45f4-9f67-c9675520ae16.png)

8. Git 업데이트

   
   $ vi frontend/deployment.yaml
       env:
       - name: PODINFO_UI_COLOR
         value: "#888888"
   $ git add .
   $ git commit -m "change color"
   $ git push

// 자동 배포 확인 $ kubectl get pods --namespace test NAME READY STATUS RESTARTS AGE backend-6597979bbf-njhtr 1/1 Running 0 8h frontend-5557476b4-t6pbp 1/1 Running 0 95s

8. 앱 업데이트 확인
![image](https://user-images.githubusercontent.com/11453229/135608423-bf5175d3-54fe-4e0d-bc5a-74f750f4b0a0.png)

참고
- https://docs.gitops.weave.works/docs/getting-started/
- https://github.com/weaveworks/weave-gitops

[GunSik2]

오류 해결

ssh: handshake 문제

• 오류

  ► Cloning ssh://git@github.com/GunSik2/podinfo-deploy.git
  Error: failed to add the app : failed to clone application repo: failed cloning user repo: ssh://git@github.com/GunSik2/podinfo-deploy.git: ssh: handshake failed: knownhosts: key is unknown

• 조치 : SSH 인증 실행하여 ~.ssh/known_host 에 등록

  $ git clone git@github.com:GunSik2/podinfo-deploy.git
  Cloning into 'podinfo-deploy'...
  The authenticity of host 'github.com (52.78.231.108)' can't be established.
  RSA key fingerprint is SHA256:nThbg6kXUpJWGl7E1IGOCspRomTxdCARLviKw6E5SY8.
  Are you sure you want to continue connecting (yes/no)? yes

  failed to create ingress: the server could not find the requested resource

• 오류

  $ kubectl create ingress frontend --rule="podinfo.14.xx.xxx.xxx.xip.io/*=frontend:9898"  -n test 
  error: failed to create ingress: the server could not find the requested resource

• 조치 : kubectl 버전 서버와 일치

  
  // 버전 차이 확인
  $ kubectl version
  Client Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.1", GitCommit:"632ed300f2c34f6d6d15ca4cef3d3c7073412212", GitTreeState:"clean", BuildDate:"2021-08-19T15:45:37Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}
  Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.20", GitCommit:"1f3e19b7beb1cc0110255668c4238ed63dadb7ad", GitTreeState:"clean", BuildDate:"2021-06-16T12:51:17Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}
  WARNING: version difference between client (1.22) and server (1.18) exceeds the supported minor version skew of +/-1

// kubectl 재설치 $ curl -LO https://dl.k8s.io/release/v1.18.0/bin/linux/amd64/kubectl $ chmod +x kubectl $ sudo mv kubectl /usr/local/bin/kubectl

// 버전 확인 $ kubectl version Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.0", GitCommit:"9e991415386e4cf155a24b1da15becaa390438d8", GitTreeState:"clean", BuildDate:"2020-03-25T14:58:59Z", GoVersion:"go1.13.8", Compiler:"gc", Platform:"linux/amd64"} Server Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.20", GitCommit:"1f3e19b7beb1cc0110255668c4238ed63dadb7ad", GitTreeState:"clean", BuildDate:"2021-06-16T12:51:17Z", GoVersion:"go1.13.15", Compiler:"gc", Platform:"linux/amd64"}

[GunSik2]

GitOps 개발자 환경

• Skaffold

참고

• https://www.weave.works/blog/weaveworks-gitops-developer-toolkit-part-one-skaffold