Translate a Docker Compose File to Kubernetes Resources

    More information can be found on the Kompose website at http://kompose.io.

    You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using or you can use one of these Kubernetes playgrounds:

    To check the version, enter kubectl version.

    Install Kompose

    We have multiple ways to install Kompose. Our preferred method is downloading the binary from the latest GitHub release.

    Kompose is released via GitHub on a three-week cycle, you can see all current releases on the GitHub release page.

    Alternatively, you can download the .

    Installing using go get pulls from the master branch with the latest development changes.

    1. go get -u github.com/kubernetes/kompose

    Kompose is in EPEL CentOS repository. If you don’t have repository already installed and enabled you can do it by running sudo yum install epel-release

    If you have EPEL enabled in your system, you can install Kompose like any other package.

    1. sudo yum -y install kompose

    Kompose is in Fedora 24, 25 and 26 repositories. You can install it like any other package.

    1. sudo dnf -y install kompose

    On macOS you can install latest release via :

    1. brew install kompose

    Use Kompose

    In a few steps, we’ll take you from Docker Compose to Kubernetes. All you need is an existing docker-compose.yml file.

    1. Go to the directory containing your docker-compose.yml file. If you don’t have one, test using this one.

      1. version: "2"
      3. services:
      5.   redis-master:
      6.     image: k8s.gcr.io/redis:e2e
      7.     ports:
      8.       - "6379"
      10.   redis-slave:
      11.     image: gcr.io/google_samples/gb-redisslave:v3
      12.     ports:
      13.       - "6379"
      14.     environment:
      15.       - GET_HOSTS_FROM=dns
      17.   frontend:
      18.     image: gcr.io/google-samples/gb-frontend:v4
      19.     ports:
      20.       - "80:80"
      21.     environment:
      22.       - GET_HOSTS_FROM=dns
      23.     labels:
      24.       kompose.service.type: LoadBalancer

    2. To convert the docker-compose.yml file to files that you can use with kubectl, run kompose convert and then kubectl apply -f <output file>.

      1. kompose convert

      The output is similar to:

      1. INFO Kubernetes file "frontend-service.yaml" created
      2.    INFO Kubernetes file "frontend-service.yaml" created
      3. INFO Kubernetes file "frontend-service.yaml" created
      4. INFO Kubernetes file "redis-master-service.yaml" created
      5.    INFO Kubernetes file "redis-master-service.yaml" created
      6. INFO Kubernetes file "redis-master-service.yaml" created
      7. INFO Kubernetes file "redis-slave-service.yaml" created
      8.    INFO Kubernetes file "redis-slave-service.yaml" created
      9. INFO Kubernetes file "redis-slave-service.yaml" created
      10. INFO Kubernetes file "frontend-deployment.yaml" created
      11.    INFO Kubernetes file "frontend-deployment.yaml" created
      12. INFO Kubernetes file "frontend-deployment.yaml" created
      13. INFO Kubernetes file "redis-master-deployment.yaml" created
      14.    INFO Kubernetes file "redis-master-deployment.yaml" created
      15. INFO Kubernetes file "redis-master-deployment.yaml" created
      16. INFO Kubernetes file "redis-slave-deployment.yaml" created
      17.    INFO Kubernetes file "redis-slave-deployment.yaml" created
      18. INFO Kubernetes file "redis-slave-deployment.yaml" created
      1.  kubectl apply -f frontend-service.yaml,redis-master-service.yaml,redis-slave-service.yaml,frontend-deployment.yaml,redis-master-deployment.yaml,redis-slave-deployment.yaml

      The output is similar to:

      1. service/frontend created
      2. service/redis-master created
      3. service/redis-slave created
      4. deployment.apps/frontend created
      5. deployment.apps/redis-master created
      6. deployment.apps/redis-slave created

    3. Access your application.

      If you’re already using minikube for your development process:

      1. minikube service frontend

      Otherwise, let’s look up what IP your service is using!

      1. kubectl describe svc frontend
      1. Namespace:              default
      2. Labels:                 service=frontend
      3. Selector:               service=frontend
      4. Type:                   LoadBalancer
      5. IP:                     10.0.0.183
      6. LoadBalancer Ingress:   192.0.2.89
      7. Port:                   80      80/TCP
      8. NodePort:               80      31144/TCP
      9. Endpoints:              172.17.0.4:80
      10. Session Affinity:       None
      11. No events.

      If you’re using a cloud provider, your IP will be listed next to LoadBalancer Ingress.

    Kompose has support for two providers: OpenShift and Kubernetes. You can choose a targeted provider using global option --provider. If no provider is specified, Kubernetes is set by default.

    kompose convert

    Kompose supports conversion of V1, V2, and V3 Docker Compose files into Kubernetes and OpenShift objects.

    1. kompose --file docker-voting.yml convert
    1. WARN Unsupported key networks - ignoring
    2. WARN Unsupported key build - ignoring
    3. INFO Kubernetes file "worker-svc.yaml" created
    5. INFO Kubernetes file "redis-svc.yaml" created
    6. INFO Kubernetes file "result-svc.yaml" created
    7. INFO Kubernetes file "vote-svc.yaml" created
    8. INFO Kubernetes file "redis-deployment.yaml" created
    9. INFO Kubernetes file "result-deployment.yaml" created
    10. INFO Kubernetes file "vote-deployment.yaml" created
    11. INFO Kubernetes file "worker-deployment.yaml" created
    12. INFO Kubernetes file "db-deployment.yaml" created
    1. ls
    1. db-deployment.yaml  docker-compose.yml         docker-gitlab.yml  redis-deployment.yaml  result-deployment.yaml  vote-deployment.yaml  worker-deployment.yaml
    2. db-svc.yaml         docker-voting.yml          redis-svc.yaml     result-svc.yaml        vote-svc.yaml           worker-svc.yaml

    You can also provide multiple docker-compose files at the same time:

    1. kompose -f docker-compose.yml -f docker-guestbook.yml convert
    1. INFO Kubernetes file "frontend-service.yaml" created         
    2. INFO Kubernetes file "mlbparks-service.yaml" created         
    3. INFO Kubernetes file "mongodb-service.yaml" created          
    4. INFO Kubernetes file "redis-master-service.yaml" created     
    5. INFO Kubernetes file "redis-slave-service.yaml" created      
    6. INFO Kubernetes file "frontend-deployment.yaml" created      
    7. INFO Kubernetes file "mlbparks-deployment.yaml" created      
    8. INFO Kubernetes file "mongodb-deployment.yaml" created       
    9. INFO Kubernetes file "mongodb-claim0-persistentvolumeclaim.yaml" created
    10. INFO Kubernetes file "redis-master-deployment.yaml" created  
    11. INFO Kubernetes file "redis-slave-deployment.yaml" created
    1. ls
    1. mlbparks-deployment.yaml  mongodb-service.yaml                       redis-slave-service.jsonmlbparks-service.yaml  
    2. frontend-deployment.yaml  mongodb-claim0-persistentvolumeclaim.yaml  redis-master-service.yaml
    3. frontend-service.yaml     mongodb-deployment.yaml                    redis-slave-deployment.yaml
    4. redis-master-deployment.yaml

    When multiple docker-compose files are provided the configuration is merged. Any configuration that is common will be over ridden by subsequent file.

    1. kompose --provider openshift --file docker-voting.yml convert
    1. WARN [worker] Service cannot be created because of missing port.
    2. INFO OpenShift file "vote-service.yaml" created             
    3. INFO OpenShift file "db-service.yaml" created               
    4. INFO OpenShift file "redis-service.yaml" created            
    5. INFO OpenShift file "result-service.yaml" created           
    6. INFO OpenShift file "vote-deploymentconfig.yaml" created    
    7. INFO OpenShift file "vote-imagestream.yaml" created         
    8. INFO OpenShift file "worker-deploymentconfig.yaml" created  
    9. INFO OpenShift file "worker-imagestream.yaml" created       
    10. INFO OpenShift file "db-deploymentconfig.yaml" created      
    11. INFO OpenShift file "db-imagestream.yaml" created           
    12. INFO OpenShift file "redis-deploymentconfig.yaml" created   
    13. INFO OpenShift file "redis-imagestream.yaml" created        
    14. INFO OpenShift file "result-deploymentconfig.yaml" created  
    15. INFO OpenShift file "result-imagestream.yaml" created

    It also supports creating buildconfig for build directive in a service. By default, it uses the remote repo for the current git branch as the source repo, and the current branch as the source branch for the build. You can specify a different source repo and branch using --build-repo and --build-branch options respectively.

    1. kompose --provider openshift --file buildconfig/docker-compose.yml convert
    1. WARN [foo] Service cannot be created because of missing port.
    2. INFO OpenShift Buildconfig using git@github.com:rtnpro/kompose.git::master as source.
    3. INFO OpenShift file "foo-deploymentconfig.yaml" created     
    4. INFO OpenShift file "foo-imagestream.yaml" created          
    5. INFO OpenShift file "foo-buildconfig.yaml" created

    Note: If you are manually pushing the OpenShift artifacts using oc create -f, you need to ensure that you push the imagestream artifact before the buildconfig artifact, to workaround this OpenShift issue: https://github.com/openshift/origin/issues/4518 .

    Build and Push Docker Images

    Kompose supports both building and pushing Docker images. When using the build key within your Docker Compose file, your image will:

    • Automatically be built with Docker using the image key specified within your file
    • Be pushed to the correct Docker repository using local credentials (located at .docker/config)

    Using an example Docker Compose file:

    Using kompose up with a build key:

    1. kompose up
    2. INFO Build key detected. Attempting to build and push image 'docker.io/foo/bar'
    3. INFO Building image 'docker.io/foo/bar' from directory 'build'
    4. INFO Pushing image 'foo/bar:latest' to registry 'docker.io'
    5. INFO Attempting authentication credentials 'https://index.docker.io/v1/
    6. INFO Successfully pushed image 'foo/bar:latest' to registry 'docker.io'
    7. 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 apply -f' commands instead.
    9. INFO Deploying application in "default" namespace
    10. INFO Successfully created Service: foo            
    11. INFO Successfully created Deployment: foo         
    13. Your application has been deployed to Kubernetes. You can run 'kubectl get deployment,svc,pods,pvc' for details.

    In order to disable the functionality, or choose to use BuildConfig generation (with OpenShift) --build (local|build-config|none) can be passed.

    1. # Disable building/pushing Docker images
    2. kompose up --build none
    4. # Generate Build Config artifacts for OpenShift
    5. kompose up --provider openshift --build build-config

    The default kompose transformation will generate Kubernetes and Services, in yaml format. You have alternative option to generate json with -j. Also, you can alternatively generate objects, Daemon Sets, or charts.

    1. kompose convert -j
    2. INFO Kubernetes file "redis-svc.json" created
    3. INFO Kubernetes file "web-svc.json" created
    4. INFO Kubernetes file "redis-deployment.json" created
    5. INFO Kubernetes file "web-deployment.json" created

    The *-deployment.json files contain the Deployment objects.

    1. kompose convert --replication-controller
    3. INFO Kubernetes file "web-svc.yaml" created
    4. INFO Kubernetes file "redis-replicationcontroller.yaml" created
    5. INFO Kubernetes file "web-replicationcontroller.yaml" created
    1. kompose convert --daemon-set
    2. INFO Kubernetes file "redis-svc.yaml" created
    3. INFO Kubernetes file "web-svc.yaml" created
    4. INFO Kubernetes file "redis-daemonset.yaml" created
    5. INFO Kubernetes file "web-daemonset.yaml" created

    The *-daemonset.yaml files contain the DaemonSet objects

    If you want to generate a Chart to be used with Helm run:

    1. kompose convert -c
    1. INFO Kubernetes file "web-svc.yaml" created
    2. INFO Kubernetes file "redis-svc.yaml" created
    3. INFO Kubernetes file "web-deployment.yaml" created
    4. INFO Kubernetes file "redis-deployment.yaml" created
    5. chart created in "./docker-compose/"
    1. tree docker-compose/
    1. docker-compose
    2. ├── Chart.yaml
    3. ├── README.md
    4. └── templates
    5.     ├── redis-deployment.yaml
    6.     ├── redis-svc.yaml
    7.     ├── web-deployment.yaml
    8.     └── web-svc.yaml

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

    Labels

    kompose supports Kompose-specific labels within the docker-compose.yml file in order to explicitly define a service’s behavior upon conversion.

    • kompose.service.type defines the type of service to be created.

    For example:

    1. version: "2"
    2. services:
    3.   nginx:
    4.     image: nginx
    5.     dockerfile: foobar
    6.     build: ./foobar
    7.     cap_add:
    8.       - ALL
    9.     container_name: foobar
    10.     labels:
    11.       kompose.service.type: nodeport
    • kompose.service.expose defines if the service needs to be made accessible from outside the cluster or not. If the value is set to “true”, the provider sets the endpoint automatically, and for any other value, the value is set as the hostname. If multiple ports are defined in a service, the first one is chosen to be the exposed.
      • For the Kubernetes provider, an ingress resource is created and it is assumed that an ingress controller has already been configured.
      • For the OpenShift provider, a route is created.

    For example:

    1. version: "2"
    2. services:
    3.   web:
    4.     image: tuna/docker-counter23
    5.     ports:
    6.      - "5000:5000"
    7.     links:
    8.      - redis
    9.     labels:
    10.       kompose.service.expose: "counter.example.com"
    11.   redis:
    12.     image: redis:3.0
    13.     ports:
    14.      - "6379"

    The currently supported options are:

    Note: The kompose.service.type label should be defined with ports only, otherwise kompose will fail.

    Restart

    If you want to create normal pods without controllers you can use restart construct of docker-compose to define that. Follow table below to see what happens on the restart value.

    docker-compose restartobject createdPod restartPolicy
    “”controller objectAlways
    alwayscontroller objectAlways
    on-failurePodOnFailure
    noPodNever

    Note: The controller object could be deployment or replicationcontroller.

    For example, the pival service will become pod down here. This container calculated value of pi.

    1. version: '2'
    3. services:
    4.   pival:
    5.     image: perl
    6.     restart: "on-failure"

    If the Docker Compose file has a volume specified for a service, the Deployment (Kubernetes) or DeploymentConfig (OpenShift) strategy is changed to “Recreate” instead of “RollingUpdate” (default). This is done to avoid multiple instances of a service from accessing a volume at the same time.

    If the Docker Compose file has service name with _ in it (eg.web_service), then it will be replaced by - and the service name will be renamed accordingly (eg.web-service). Kompose does this because “Kubernetes” doesn’t allow _ in object name.

    Please note that changing service name might break some files.

    Kompose supports Docker Compose versions: 1, 2 and 3. We have limited support on versions 2.1 and 3.2 due to their experimental nature.

    A full list on compatibility between all three versions is listed in our including a list of all incompatible Docker Compose keys.