kompose

README

Kubernetes compose (Kompose)

===============================

kompose is a tool to help users familiar with docker-compose move to Kubernetes support. It takes a Docker Compose file and translates it into Kubernetes objects, it then submits those objects to a Kubernetes endpoint.

kompose is a convenience tool to go from local Docker development to managing your application with Kubernetes. We don't assume that the transformation from docker compose format to Kubernetes API objects will be perfect, but it helps tremendously to start Kubernetizing your application.

Download

Grab the latest release

Usage

You need a Docker Compose file handy. There is a sample gitlab compose file in the samples/ directory for testing. You will convert the compose file to K8s objects with kompose k8s convert.

$ cd examples/

$ ls
docker-gitlab.yml

$ kompose convert -f docker-gitlab.yml -y

$ ls
docker-gitlab.yml       gitlab-rc.yaml   postgresql-deployment.yaml  postgresql-svc.yaml      redisio-rc.yaml
gitlab-deployment.yaml  gitlab-svc.yaml  postgresql-rc.yaml          redisio-deployment.yaml  redisio-svc.yaml

Next step you will submit these above objects to a kubernetes endpoint that is automatically taken from kubectl.

$ kompose up

Check that the replication controllers and services have been created.

$ kubectl get rc
NAME         DESIRED   CURRENT   AGE
gitlab       1         1         1m
postgresql   1         1         1m
redisio      1         1         1m

$ kubectl get svc
NAME         CLUSTER-IP     EXTERNAL-IP   PORT(S)               AGE
gitlab       10.0.247.129   nodes         10080/TCP,10022/TCP   1m
kubernetes   10.0.0.1       <none>        443/TCP               17h
postgresql   10.0.237.13    <none>        5432/TCP              1m
redisio      10.0.242.93    <none>        6379/TCP              1m

By default, svc generated by kompose uses Type: ClusterIP which means svc is only accessible internally. Sometimes you might be interesting to make it public from outside, simply run:

$ kubectl edit svc gitlab

Change Service.Spec.Type to NodePort and save.

$ kubectl describe svc gitlab
Name:                       gitlab
Namespace:                  default
Labels:                     service=gitlab
Selector:                   service=gitlab
Type:                       NodePort
IP:                             10.0.247.129
Port:                       10080       10080/TCP
NodePort:                   10080       31925/TCP
Endpoints:                  10.244.0.12:80
Port:                       10022       10022/TCP
NodePort:                   10022       30232/TCP
Endpoints:                  10.244.0.12:22
Session Affinity:       None
No events.

Then you can access to gitlab at: http://Node_IP:31925

kompose also allows you to list the replication controllers and services with the ps subcommand. You can delete them with the delete subcommand.

$ kompose ps --rc
Name           Containers     Images                        Replicas  Selectors           
redisio        redisio        sameersbn/redis               1         service=redisio
postgresql     postgresql     sameersbn/postgresql:9.4-18   1         service=postgresql
gitlab         gitlab         sameersbn/gitlab:8.6.4        1         service: gitlab

$ kompose ps --svc
Name         Cluster IP          Ports                   Selectors
gitlab       10.0.247.129        TCP(10080),TCP(10022)   service=gitlab
postgresql   10.0.237.13         TCP(5432)               service=postgresql
redisio      10.0.242.93         TCP(6379)               service=redisio


$ kompose delete --rc --name gitlab
$ kompose ps --rc
Name           Containers     Images                        Replicas  Selectors
redisio        redisio        sameersbn/redis               1         service=redisio
postgresql     postgresql     sameersbn/postgresql:9.4-18   1         service=postgresql

And finally you can scale a replication controller with scale.

$ kompose scale --scale 3 --rc redisio
Scaling redisio to: 3
$ kompose ps --rc
Name           Containers     Images                        Replicas  Selectors           
redisio        redisio        sameersbn/redis               3         service=redisio

Note that you can of course manage the services and replication controllers that have been created with kubectl. The command of kompose have been extended to match the docker-compose commands.

Alternate formats

The default kompose transformation will generate replication controllers and services and in format of json. You have alternative option to generate yaml with -y. Also, you can alternatively generate Deployment objects, DeamonSet, ReplicaSet or Helm charts.

$ kompose convert -d -y
$ ls
$ tree
.
├── docker-compose.yml
├── redis-deployment.yaml
├── redis-rc.yaml
├── redis-svc.yaml
├── web-deployment.yaml
└── web-rc.yaml

The *deployment.yaml files contain the Deployments objects

$ kompose convert --ds -y
$ tree .
  .
  ├── redis-daemonset.yaml
  ├── redis-rc.yaml
  ├── redis-svc.yaml
  ├── web-daemonset.yaml
  ├── web-rc.yaml
  └── web-svc.yaml

The *daemonset.yaml files contain the DaemonSet objects

$ kompose convert --rs -y
$ tree .
.
├── redis-rc.yaml
├── redis-replicaset.yaml
├── redis-svc.yaml
├── web-rc.yaml
├── web-replicaset.yaml
└── web-svc.yaml

The *replicaset.yaml files contain the ReplicaSet objects

$ kompose convert -c -y
$ tree docker-compose/
docker-compose/
├── Chart.yaml
├── README.md
└── manifests
    ├── redis-rc.yaml
    ├── redis-svc.yaml
    └── web-rc.yaml

The chart structure is aimed at providing a skeleton for building your Helm charts.

Building

Building with go

• You need go v1.5
• You need to set export GO15VENDOREXPERIMENT=1 environment variable
• If your working copy is not in your GOPATH, you need to set it accordingly.

$ go build -o kompose ./cli/main

Contributing and Issues

kompose is a work in progress, we will see how far it takes us. We welcome any pull request to make it even better. If you find any issues, please file it.

Community, discussion, contribution, and support

Learn how to engage with the Kubernetes community on the community page.

You can reach the maintainers of this project at:

• Slack: #kubernetes-dev
• Mailing List: https://groups.google.com/forum/#!forum/kubernetes-dev

Code of conduct

Participation in the Kubernetes community is governed by the Kubernetes Code of Conduct.