Translate a Docker Compose File to Kubernetes Resources
What’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 http://kompose.io.
- Before you begin
- Install Kompose
- Use Kompose
- User Guide
kompose convert
kompose up
kompose down
- Build and Push Docker Images
- Alternative Conversions
- Labels
- Restart
- Docker Compose Versions
Before you begin
You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using Minikube, 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.
# Linux
curl -L https://github.com/kubernetes/kompose/releases/download/v1.21.0/kompose-linux-amd64 -o kompose
# macOS
curl -L https://github.com/kubernetes/kompose/releases/download/v1.21.0/kompose-darwin-amd64 -o kompose
# Windows
curl -L https://github.com/kubernetes/kompose/releases/download/v1.21.0/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
Kompose is in EPEL CentOS repository.
If you don’t have EPEL 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.
sudo yum -y install kompose
Kompose is in Fedora 24, 25 and 26 repositories. You can install it just like any other package.
sudo dnf -y install kompose
On macOS you can install latest release via Homebrew:
brew install kompose
Use Kompose
In just 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.version: "2" services: redis-master: image: k8s.gcr.io/redis:e2e ports: - "6379" redis-slave: image: gcr.io/google_samples/gb-redisslave:v3 ports: - "6379" environment: - GET_HOSTS_FROM=dns frontend: image: gcr.io/google-samples/gb-frontend:v4 ports: - "80:80" environment: - GET_HOSTS_FROM=dns labels: kompose.service.type: LoadBalancer
Run the
kompose up
command to deploy to Kubernetes directly, or skip to the next step instead to generate a file to use withkubectl
.$ kompose up 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. INFO Successfully created Service: redis INFO Successfully created Service: web INFO Successfully created Deployment: redis INFO Successfully created Deployment: web Your application has been deployed to Kubernetes. You can run 'kubectl get deployment,svc,pods,pvc' for details.
To convert the
docker-compose.yml
file to files that you can use withkubectl
, runkompose convert
and thenkubectl apply -f <output file>
.$ kompose convert INFO Kubernetes file "frontend-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 "redis-master-deployment.yaml" created INFO Kubernetes file "redis-slave-deployment.yaml" created
$ 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 service/frontend created service/redis-master created service/redis-slave created deployment.apps/frontend created deployment.apps/redis-master created deployment.apps/redis-slave created
Your deployments are running in Kubernetes.
Access your application.
If you’re already using
minikube
for your development process:$ minikube service frontend
Otherwise, let’s look up what IP your service is using!
$ kubectl describe svc frontend Name: frontend Namespace: default Labels: service=frontend Selector: service=frontend Type: LoadBalancer IP: 10.0.0.183 LoadBalancer Ingress: 192.0.2.89 Port: 80 80/TCP NodePort: 80 31144/TCP Endpoints: 172.17.0.4:80 Session Affinity: None No events.
If you’re using a cloud provider, your IP will be listed next to
LoadBalancer Ingress
.$ curl http://192.0.2.89
User Guide
- CLI
- Documentation
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.
Kubernetes
$ kompose --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 over ridden by subsequent file.
OpenShift
$ kompose --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 usingoc 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 .
kompose up
Kompose supports a straightforward way to deploy your “composed” application to Kubernetes or OpenShift via kompose up
.
Kubernetes
$ kompose --file ./examples/docker-guestbook.yml up
We are going to create Kubernetes deployments and services for your Dockerized application.
If you need different kind of resources, use the 'kompose convert' and 'kubectl apply -f' commands instead.
INFO Successfully created service: redis-master
INFO Successfully created service: redis-slave
INFO Successfully created service: frontend
INFO Successfully created deployment: redis-master
INFO Successfully created deployment: redis-slave
INFO Successfully created deployment: frontend
Your application has been deployed to Kubernetes. You can run 'kubectl get deployment,svc,pods' for details.
$ kubectl get deployment,svc,pods
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
deployment.extensions/frontend 1 1 1 1 4m
deployment.extensions/redis-master 1 1 1 1 4m
deployment.extensions/redis-slave 1 1 1 1 4m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/frontend ClusterIP 10.0.174.12 <none> 80/TCP 4m
service/kubernetes ClusterIP 10.0.0.1 <none> 443/TCP 13d
service/redis-master ClusterIP 10.0.202.43 <none> 6379/TCP 4m
service/redis-slave ClusterIP 10.0.1.85 <none> 6379/TCP 4m
NAME READY STATUS RESTARTS AGE
pod/frontend-2768218532-cs5t5 1/1 Running 0 4m
pod/redis-master-1432129712-63jn8 1/1 Running 0 4m
pod/redis-slave-2504961300-nve7b 1/1 Running 0 4m
Note:
- You must have a running Kubernetes cluster with a pre-configured kubectl context.
- Only deployments and services are generated and deployed to Kubernetes. If you need different kind of resources, use the
kompose convert
andkubectl apply -f
commands instead.
OpenShift
$ kompose --file ./examples/docker-guestbook.yml --provider openshift up
We are going to create OpenShift DeploymentConfigs and Services for your Dockerized application.
If you need different kind of resources, use the 'kompose convert' and 'oc create -f' commands instead.
INFO Successfully created service: redis-slave
INFO Successfully created service: frontend
INFO Successfully created service: redis-master
INFO Successfully created deployment: redis-slave
INFO Successfully created ImageStream: redis-slave
INFO Successfully created deployment: frontend
INFO Successfully created ImageStream: frontend
INFO Successfully created deployment: redis-master
INFO Successfully created ImageStream: redis-master
Your application has been deployed to OpenShift. You can run 'oc get dc,svc,is' for details.
$ oc get dc,svc,is
NAME REVISION DESIRED CURRENT TRIGGERED BY
dc/frontend 0 1 0 config,image(frontend:v4)
dc/redis-master 0 1 0 config,image(redis-master:e2e)
dc/redis-slave 0 1 0 config,image(redis-slave:v1)
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
svc/frontend 172.30.46.64 <none> 80/TCP 8s
svc/redis-master 172.30.144.56 <none> 6379/TCP 8s
svc/redis-slave 172.30.75.245 <none> 6379/TCP 8s
NAME DOCKER REPO TAGS UPDATED
is/frontend 172.30.12.200:5000/fff/frontend
is/redis-master 172.30.12.200:5000/fff/redis-master
is/redis-slave 172.30.12.200:5000/fff/redis-slave v1
Note:
- You must have a running OpenShift cluster with a pre-configured
oc
context (oc login
)
kompose down
Once you have deployed “composed” application to Kubernetes, $ kompose down
will help you to take the application out by deleting its deployments and services. If you need to remove other resources, use the ‘kubectl’ command.
$ kompose --file docker-guestbook.yml down
INFO Successfully deleted service: redis-master
INFO Successfully deleted deployment: redis-master
INFO Successfully deleted service: redis-slave
INFO Successfully deleted deployment: redis-slave
INFO Successfully deleted service: frontend
INFO Successfully deleted deployment: frontend
Note:
- You must have a running Kubernetes cluster with a pre-configured kubectl context.
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:
version: "2"
services:
foo:
build: "./build"
image: docker.io/foo/bar
Using kompose up
with a build
key:
$ kompose up
INFO Build key detected. Attempting to build and push image 'docker.io/foo/bar'
INFO Building image 'docker.io/foo/bar' from directory 'build'
INFO Image 'docker.io/foo/bar' from directory 'build' built successfully
INFO Pushing image 'foo/bar:latest' to registry 'docker.io'
INFO Attempting authentication credentials 'https://index.docker.io/v1/
INFO Successfully pushed image 'foo/bar:latest' to registry 'docker.io'
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.
INFO Deploying application in "default" namespace
INFO Successfully created Service: foo
INFO Successfully created Deployment: foo
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.
# Disable building/pushing Docker images
$ kompose up --build none
# Generate Build Config artifacts for OpenShift
$ kompose up --provider openshift --build build-config
Alternative Conversions
The 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 Daemon Set objects
If you want to generate a Chart to be used with Helm simply do:
$ 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.
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:
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:
Key | Value |
---|---|
kompose.service.type | nodeport / clusterip / loadbalancer |
kompose.service.expose | true / hostname |
Note: Thekompose.service.type
label should be defined withports
only, otherwisekompose
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 restart |
object created | Pod restartPolicy |
---|---|---|
"" |
controller object | Always |
always |
controller object | Always |
on-failure |
Pod | OnFailure |
no |
Pod | Never |
Note: The controller object could bedeployment
orreplicationcontroller
, etc.
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 Config’s
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 docker-compose
files.
Docker Compose Versions
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 conversion document including a list of all incompatible Docker Compose keys.
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