K8S Utility No. 5 - kompose

This article was last updated on: July 24, 2024 am

Opening

📜 introduction：

  • Sharpen knives and do not chop wood by mistake
  • Better tools make good work

Kubernetes + Compose = Kompose

Conversion tools from Docker Compose to Kubernetes

What is Kompose?

Kompose is a tool for converting dockercompose to container orchestrators such as Kubernetes (or OpenShift).

Why do developers love it?

  • Simplify the development process with Docker Compose, then deploy containers to production clusters
  • Convert yours docker-compose.yaml A simple command is required kompose convert

Easy as pie

  1. Find one docker-compose.yaml File;
  2. Execute:kompose convert
  3. execute kubectl apply And check your k8s cluster for your newly deployed containers!
1
2
3
4
5
6
7
8
9
10
11
$ 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

Actual combat

For example, I want to install RssHub on the K8S, which is officially provided docker-compose.yml:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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:

execute kompose convert After, from docker-compose.yml Generate the following files:

1
2
3
4
5
6
7
$ 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

Each docker-compose container will be born as a deployment and automatically convert fields such as label and env for you rsshub-deployment.yaml Example:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
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 ports section, converted to SVC rsshub-service.yaml Example:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
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 volumes field, converted to PVC redis-data-persistentvolumeclaim.yaml Example:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  creationTimestamp: null
  labels:
    io.kompose.service: redis-data
  name: redis-data
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 100Mi
status: {}

At ease!

Installation

1
2
3
4
5
6
7
8
# 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

🎉🎉🎉