It's Me, Tommy

Kubernetes: Kompose

Kompose is a conversion tool for Docker Compose to container orchestrators such as Kubernetes (or OpenShift). In this example, I’ll be using a Mac along with Minikube. I’ll be exposing a NodePort in order to view the services within a browser.

Install

macOS: Homebrew

brew install kompose

Create docker-comose.yaml

vi docker-compose.yaml
version: '3'

services:
  httpd:
    image: httpd
    ports:
      - 80:80
    labels:
      kompose.service.type: Nodeport
  nginx:
    image: nginx
    ports:
      - 80:80
    labels:
      kompose.service.type: Nodeport

Create

kompose up
INFO We are going to create Kubernetes Deployments, Services and PersistentVolumeClaims for your Dockerized application. If you need different kind of resources, use the 'kompose convert' and 'kubectl create -f' commands instead.

INFO Deploying application in "default" namespace
INFO Successfully created Service: httpd
INFO Successfully created Service: nginx
INFO Successfully created Deployment: httpd
INFO Successfully created Deployment: nginx

Your application has been deployed to Kubernetes. You can run 'kubectl get deployment,svc,pods,pvc' for details.

View details

kubectl get deployment,svc,pods,pvc
NAME                          DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
deployment.extensions/httpd   1         1         1            1           18s
deployment.extensions/nginx   1         1         1            1           18s

NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
service/httpd        NodePort    10.105.90.34    <none>        80:32735/TCP   18s
service/kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        47m
service/nginx        NodePort    10.107.12.222   <none>        80:30180/TCP   18s

NAME                         READY     STATUS    RESTARTS   AGE
pod/httpd-69c7f65b8c-xxlld   1/1       Running   0          18s
pod/nginx-5684848c75-8szsk   1/1       Running   0          18s

View service in browser

minikube service httpd
minikube service nginx

Delete

kompose down
INFO Deleting application in "default" namespace
INFO Successfully deleted Service: httpd
INFO Successfully deleted Service: nginx
INFO Successfully deleted Deployment: httpd
INFO Successfully deleted Deployment: nginx

Convert

Kompose also has the ability to take existing compose files and generate the related Kubernetes Manifest files.

kompose convert

ll | grep yaml
-rw-r--r--@ 1 tommy  staff   223B Jan  2 10:49 docker-compose.yaml
-rw-r--r--@ 1 tommy  staff   564B Jan  2 10:50 httpd-deployment.yaml
-rw-r--r--@ 1 tommy  staff   381B Jan  2 10:50 httpd-service.yaml
-rw-r--r--@ 1 tommy  staff   564B Jan  2 10:50 nginx-deployment.yaml
-rw-r--r--@ 1 tommy  staff   381B Jan  2 10:50 nginx-service.yaml

Kompose also supports different Kubernetes distributions, for example OpenShift.

kompose --provider openshift convert

By default, Kompose generates YAML files. It is also possible to generate JSON based files by specifying the -j parameter.

kompose convert -j

Tommy Elmesewdy

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