# Translate a Docker Compose File to Kubernetes Resources

Translate a Docker Compose File to Kubernetes ResourcesWhat's Kompose? It's a conversion tool for all things compose (namely Docker Compose) to container orchestrators (Kubernetes or OpenShift).More information can be found on the Kompose website at https://kompose.io/.Before you beginYou 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 minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesTo check the version, enter kubectl version.Install KomposeWe 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.# Linux curl -L https://github.com/kubernetes/kompose/releases/download/v1.34.0/kompose-linux-amd64 -o kompose # macOS curl -L https://github.com/kubernetes/kompose/releases/download/v1.34.0/kompose-darwin-amd64 -o kompose # Windows curl -L https://github.com/kubernetes/kompose/releases/download/v1.34.0/kompose-windows-amd64.exe -o kompose.exe chmod +x kompose sudo mv ./kompose /usr/local/bin/kompose Alternatively, you can download the tarball.Installing using go get pulls from the master branch with the latest development changes.go get -u github.com/kubernetes/kompose On macOS you can install the latest release via Homebrew:brew install kompose Use KomposeIn a few steps, we'll take you from Docker Compose to Kubernetes. All you need is an existing docker-compose.yml file.Go to the directory containing your docker-compose.yml file. If you don't have one, test using this one. services: redis-leader: container_name: redis-leader image: redis ports: - "6379" redis-replica: container_name: redis-replica image: redis ports: - "6379" command: redis-server --replicaof redis-leader 6379 --dir /tmp web: container_name: web image: quay.io/kompose/web ports: - "8080:8080" environment: - GET_HOSTS_FROM=dns labels: kompose.service.type: LoadBalancer 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>.kompose convert The output is similar to:INFO Kubernetes file "redis-leader-service.yaml" created INFO Kubernetes file "redis-replica-service.yaml" created INFO Kubernetes file "web-tcp-service.yaml" created INFO Kubernetes file "redis-leader-deployment.yaml" created INFO Kubernetes file "redis-replica-deployment.yaml" created INFO Kubernetes file "web-deployment.yaml" created kubectl apply -f web-tcp-service.yaml,redis-leader-service.yaml,redis-replica-service.yaml,web-deployment.yaml,redis-leader-deployment.yaml,redis-replica-deployment.yaml The output is similar to:deployment.apps/redis-leader created deployment.apps/redis-replica created deployment.apps/web created service/redis-leader created service/redis-replica created service/web-tcp created Your deployments are running in Kubernetes.Access your application.If you're already using minikube for your development process:minikube service web-tcp Otherwise, let's look up what IP your service is using!kubectl describe svc web-tcp Name: web-tcp Namespace: default Labels: io.kompose.service=web-tcp Annotations: kompose.cmd: kompose convert kompose.service.type: LoadBalancer kompose.version: 1.33.0 (3ce457399) Selector: io.kompose.service=web Type: LoadBalancer IP Family Policy: SingleStack IP Families: IPv4 IP: 10.102.30.3 IPs: 10.102.30.3 Port: 8080 8080/TCP TargetPort: 8080/TCP NodePort: 8080 31624/TCP Endpoints: 10.244.0.5:8080 Session Affinity: None External Traffic Policy: Cluster Events: <none> If you're using a cloud provider, your IP will be listed next to LoadBalancer Ingress.curl http://192.0.2.89 Clean-up.After you are finished testing out the example application deployment, simply run the following command in your shell to delete the resources used.kubectl delete -f web-tcp-service.yaml,redis-leader-service.yaml,redis-replica-service.yaml,web-deployment.yaml,redis-leader-deployment.yaml,redis-replica-deployment.yaml User GuideCLIkompose convertDocumentationAlternative ConversionsLabelsRestartDocker Compose VersionsKompose 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 convertKompose supports conversion of V1, V2, and V3 Docker Compose files into Kubernetes and OpenShift objects.Kubernetes kompose convert examplekompose --file docker-voting.yml convert WARN Unsupported key networks - ignoring WARN Unsupported key build - ignoring INFO Kubernetes file "worker-svc.yaml" created INFO Kubernetes file "db-svc.yaml" created INFO Kubernetes file "redis-svc.yaml" created INFO Kubernetes file "result-svc.yaml" created INFO Kubernetes file "vote-svc.yaml" created INFO Kubernetes file "redis-deployment.yaml" created INFO Kubernetes file "result-deployment.yaml" created INFO Kubernetes file "vote-deployment.yaml" created INFO Kubernetes file "worker-deployment.yaml" created INFO Kubernetes file "db-deployment.yaml" created ls db-deployment.yaml docker-compose.yml docker-gitlab.yml redis-deployment.yaml result-deployment.yaml vote-deployment.yaml worker-deployment.yaml 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:kompose -f docker-compose.yml -f docker-guestbook.yml convert INFO Kubernetes file "frontend-service.yaml" created INFO Kubernetes file "mlbparks-service.yaml" created INFO Kubernetes file "mongodb-service.yaml" created INFO Kubernetes file "redis-master-service.yaml" created INFO Kubernetes file "redis-slave-service.yaml" created INFO Kubernetes file "frontend-deployment.yaml" created INFO Kubernetes file "mlbparks-deployment.yaml" created INFO Kubernetes file "mongodb-deployment.yaml" created INFO Kubernetes file "mongodb-claim0-persistentvolumeclaim.yaml" created INFO Kubernetes file "redis-master-deployment.yaml" created INFO Kubernetes file "redis-slave-deployment.yaml" created ls mlbparks-deployment.yaml mongodb-service.yaml redis-slave-service.jsonmlbparks-service.yaml frontend-deployment.yaml mongodb-claim0-persistentvolumeclaim.yaml redis-master-service.yaml frontend-service.yaml mongodb-deployment.yaml redis-slave-deployment.yaml redis-master-deployment.yaml When multiple docker-compose files are provided the configuration is merged. Any configuration that is common will be overridden by subsequent file.OpenShift kompose convert examplekompose --provider openshift --file docker-voting.yml convert WARN [worker] Service cannot be created because of missing port. INFO OpenShift file "vote-service.yaml" created INFO OpenShift file "db-service.yaml" created INFO OpenShift file "redis-service.yaml" created INFO OpenShift file "result-service.yaml" created INFO OpenShift file "vote-deploymentconfig.yaml" created INFO OpenShift file "vote-imagestream.yaml" created INFO OpenShift file "worker-deploymentconfig.yaml" created INFO OpenShift file "worker-imagestream.yaml" created INFO OpenShift file "db-deploymentconfig.yaml" created INFO OpenShift file "db-imagestream.yaml" created INFO OpenShift file "redis-deploymentconfig.yaml" created INFO OpenShift file "redis-imagestream.yaml" created INFO OpenShift file "result-deploymentconfig.yaml" created 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.kompose --provider openshift --file buildconfig/docker-compose.yml convert WARN [foo] Service cannot be created because of missing port. INFO OpenShift Buildconfig using git@github.com:rtnpro/kompose.git::master as source. INFO OpenShift file "foo-deploymentconfig.yaml" created INFO OpenShift file "foo-imagestream.yaml" created 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 .Alternative ConversionsThe default kompose transformation will generate Kubernetes Deployments and Services, in yaml format. You have alternative option to generate json with -j. Also, you can alternatively generate Replication Controllers objects, Daemon Sets, or Helm charts.kompose convert -j INFO Kubernetes file "redis-svc.json" created INFO Kubernetes file "web-svc.json" created INFO Kubernetes file "redis-deployment.json" created INFO Kubernetes file "web-deployment.json" created The *-deployment.json files contain the Deployment objects.kompose convert --replication-controller INFO Kubernetes file "redis-svc.yaml" created INFO Kubernetes file "web-svc.yaml" created INFO Kubernetes file "redis-replicationcontroller.yaml" created INFO Kubernetes file "web-replicationcontroller.yaml" created The *-replicationcontroller.yaml files contain the Replication Controller objects. If you want to specify replicas (default is 1), use --replicas flag: kompose convert --replication-controller --replicas 3.kompose convert --daemon-set INFO Kubernetes file "redis-svc.yaml" created INFO Kubernetes file "web-svc.yaml" created INFO Kubernetes file "redis-daemonset.yaml" created 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:kompose convert -c INFO Kubernetes file "web-svc.yaml" created INFO Kubernetes file "redis-svc.yaml" created INFO Kubernetes file "web-deployment.yaml" created INFO Kubernetes file "redis-deployment.yaml" created chart created in "./docker-compose/" tree docker-compose/ docker-compose ├── Chart.yaml ├── README.md └── templates ├── redis-deployment.yaml ├── redis-svc.yaml ├── web-deployment.yaml └── web-svc.yaml The chart structure is aimed at providing a skeleton for building your Helm charts.Labelskompose 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:version: "2" services: nginx: image: nginx dockerfile: foobar build: ./foobar cap_add: - ALL container_name: foobar labels: 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:version: "2" services: web: image: tuna/docker-counter23 ports: - "5000:5000" links: - redis labels: kompose.service.expose: "counter.example.com" redis: image: redis:3.0 ports: - "6379" The currently supported options are:KeyValuekompose.service.typenodeport / clusterip / loadbalancerkompose.service.exposetrue / hostnameNote:The kompose.service.type label should be defined with ports only, otherwise kompose will fail.RestartIf 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 objectAlwaysalwayscontroller objectAlwayson-failurePodOnFailurenoPodNeverNote:The controller object could be deployment or replicationcontroller.For example, the pival service will become pod down here. This container calculated value of pi.version: '2' services: pival: image: perl command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"] restart: "on-failure" Warning about Deployment ConfigurationsIf 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 (for example, web_service), then it will be replaced by - and the service name will be renamed accordingly (for example, web-service). Kompose does this because "Kubernetes" doesn't allow _ in object name.Please note that changing service name might break some docker-compose files.Docker Compose VersionsKompose 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 conversion document including a list of all incompatible Docker Compose keys.