K8S 实用工具之五 -kompose

本文最后更新于:2024年7月24日 晚上

开篇

📜 引言

  • 磨刀不误砍柴工
  • 工欲善其事必先利其器

Kubernetes + Compose = Kompose

从 Docker Compose 到 Kubernetes 的转换工具

什么是 Kompose?

Kompose 是 dockercompose 到 Kubernetes (或 OpenShift) 等容器编排器的转换工具。

为什么开发者喜欢它?

  • 使用 Docker Compose 简化开发过程,然后将容器部署到生产集群
  • 转换你的 docker-compose.yaml 需要一个简单的命令 kompose convert

易如反掌

  1. 找一个 docker-compose.yaml 文件;
  2. 执行:kompose convert
  3. 执行 kubectl apply 并检查您的 k8s 集群为您新部署的容器!
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$ wget https://raw.githubusercontent.com/kubernetes/kompose/master/examples/docker-compose-v3.yaml -O docker-compose.yaml

$ kompose convert

$ kubectl apply -f .

$ kubectl get po
NAME READY STATUS RESTARTS AGE
frontend-591253677-5t038 1/1 Running 0 10s
redis-master-2410703502-9hshf 1/1 Running 0 10s
redis-slave-4049176185-hr1lr 1/1 Running 0 10s

实战

比如我要在 K8S 上安装 RssHub,这是官方提供的 docker-compose.yml:

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version: '3'
services:
rsshub:
image: diygod/rsshub
restart: always
ports:
- '1200:1200'
environment:
NODE_ENV: production
CACHE_TYPE: redis
REDIS_URL: 'redis://redis:6379/'
PUPPETEER_WS_ENDPOINT: 'ws://browserless:3000'
depends_on:
- redis
- browserless
browserless:
# See issue 6680
image: browserless/chrome:1.43-chrome-stable
restart: always
ulimits:
core:
hard: 0
soft: 0
redis:
image: redis:alpine
restart: always
volumes:
- redis-data:/data
volumes:
redis-data:

执行 kompose convert 后,从 docker-compose.yml 生成以下文件:

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$ ll
.rw-r--r-- 711 casey 1 Dec 21:20 browserless-deployment.yaml
.rw-r--r-- 715 casey 1 Dec 21:20 docker-compose.yml
.rw-r--r-- 243 casey 1 Dec 21:20 redis-data-persistentvolumeclaim.yaml
.rw-r--r-- 867 casey 1 Dec 21:20 redis-deployment.yaml
.rw-r--r-- 1.0k casey 1 Dec 21:20 rsshub-deployment.yaml
.rw-r--r-- 352 casey 1 Dec 21:20 rsshub-service.yaml

每个 docker-compose 容器,会生成为一个 deployment,并为你自动转换好 label 和 env 等字段,以 rsshub-deployment.yaml 为例:

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apiVersion: apps/v1
kind: Deployment
metadata:
annotations:
kompose.cmd: kompose convert
kompose.version: 1.26.0 (40646f47)
creationTimestamp: null
labels:
io.kompose.service: rsshub
name: rsshub
spec:
replicas: 1
selector:
matchLabels:
io.kompose.service: rsshub
strategy: {}
template:
metadata:
annotations:
kompose.cmd: kompose convert
kompose.version: 1.26.0 (40646f47)
creationTimestamp: null
labels:
io.kompose.service: rsshub
spec:
containers:
- env:
- name: CACHE_TYPE
value: redis
- name: NODE_ENV
value: production
- name: PUPPETEER_WS_ENDPOINT
value: ws://browserless:3000
- name: REDIS_URL
value: redis://redis:6379/
image: diygod/rsshub
name: rsshub
ports:
- containerPort: 1200
resources: {}
restartPolicy: Always
status: {}

Docker compose 的 ports 部分,会转换为 SVC,以 rsshub-service.yaml 为例:

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apiVersion: v1
kind: Service
metadata:
annotations:
kompose.cmd: kompose convert
kompose.version: 1.26.0 (40646f47)
creationTimestamp: null
labels:
io.kompose.service: rsshub
name: rsshub
spec:
ports:
- name: "1200"
port: 1200
targetPort: 1200
selector:
io.kompose.service: rsshub
status:
loadBalancer: {}

Docker compose 的 volumes 字段,会转换为 PVC,以 redis-data-persistentvolumeclaim.yaml 为例:

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apiVersion: v1
kind: PersistentVolumeClaim
metadata:
creationTimestamp: null
labels:
io.kompose.service: redis-data
name: redis-data
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 100Mi
status: {}

安逸!

安装

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# Linux
curl -L https://github.com/kubernetes/kompose/releases/download/v1.25.0/kompose-linux-amd64 -o kompose

# macOS
curl -L https://github.com/kubernetes/kompose/releases/download/v1.25.0/kompose-darwin-amd64 -o kompose

chmod +x kompose
sudo mv ./kompose /usr/local/bin/kompose

That’s All

🎉🎉🎉

参考链接


K8S 实用工具之五 -kompose
https://ewhisper.cn/posts/35291/
作者
东风微鸣
发布于
2021年12月13日
许可协议