podman-kube-generate - Man Page
Generate Kubernetes YAML based on containers, pods or volumes
Synopsis
podman kube generate [options] container... | pod... | volume...
Description
podman kube generate generates Kubernetes YAML (v1 specification) from Podman containers, pods or volumes. Regardless of whether the input is for containers or pods, Podman generates the specification as a Pod by default. The input may be in the form of one or more containers, pods or volumes names or IDs.
Podman Containers or Pods
Volumes appear in the generated YAML according to two different volume types. Bind-mounted volumes become hostPath volume types and named volumes become persistentVolumeClaim volume types. Generated hostPath volume types are one of three subtypes depending on the state of the host path: DirectoryOrCreate when no file or directory exists at the host, Directory when host path is a directory, or File when host path is a file. The value for claimName for a persistentVolumeClaim is the name of the named volume registered in Podman.
Potential name conflicts between volumes are avoided by using a standard naming scheme for each volume type. The hostPath volume types are named according to the path on the host machine, replacing forward slashes with hyphens less any leading and trailing forward slashes. The special case of the filesystem root, /, translates to the name root. Additionally, the name is suffixed with -host to avoid naming conflicts with persistentVolumeClaim volumes. Each persistentVolumeClaim volume type uses the name of its associated named volume suffixed with -pvc.
Note that if an init container is created with type once and the pod has been started, it does not show up in the generated kube YAML as once type init containers are deleted after they are run. If the pod has only been created and not started, it is in the generated kube YAML. Init containers created with type always are always generated in the kube YAML as they are never deleted, even after running to completion.
Note: When using volumes and generating a Kubernetes YAML for an unprivileged and rootless podman container on an SELinux enabled system, one of the following options must be completed:
* Add the "privileged: true" option to the pod spec
* Add type: spc_t under the securityContext seLinuxOptions in the pod spec
* Relabel the volume via the CLI command chcon -t container_file_t -R <directory>
Once completed, the correct permissions are in place to access the volume when the pod/container is created in a Kubernetes cluster.
Note that the generated Kubernetes YAML file can be used to re-run the deployment via podman-play-kube(1).
Note that if the pod being generated was created with the --infra-name flag set, then the generated kube yaml will have the io.podman.annotations.infra.name set where the value is the name of the infra container set by the user.
Note that both Deployment and DaemonSet can only have restartPolicy set to Always.
Note that Job can only have restartPolicy set to OnFailure or Never. By default, podman sets it to Never when generating a kube yaml using kube generate.
Options
--filename, -f=filename
Output to the given file instead of STDOUT. If the file already exists, kube generate refuses to replace it and returns an error.
--podman-only
Add podman-only reserved annotations in generated YAML file (Cannot be used by Kubernetes)
--replicas, -r=replica count
The value to set replicas to when generating a Deployment kind. Note: this can only be set with the option --type=deployment.
--service, -s
Generate a Kubernetes service object in addition to the Pods. Used to generate a Service specification for the corresponding Pod output. In particular, if the object has portmap bindings, the service specification includes a NodePort declaration to expose the service. A random port is assigned by Podman in the specification.
--type, -t=pod | deployment | daemonset | job
The Kubernetes kind to generate in the YAML file. Currently, the only supported Kubernetes specifications are Pod, Deployment, Job, and DaemonSet. By default, the Pod specification is generated.
Examples
Create Kubernetes Pod YAML for the specified container.
$ podman kube generate some-mariadb # Save the output of this file and use kubectl create -f to import # it into Kubernetes. # # Created with podman-4.8.2 # NOTE: If you generated this yaml from an unprivileged and rootless podman container on an SELinux # enabled system, check the podman generate kube man page for steps to follow to ensure that your pod/container # has the right permissions to access the volumes added. --- apiVersion: v1 kind: Pod metadata: creationTimestamp: "2024-01-09T02:24:55Z" labels: app: some-mariadb-pod name: some-mariadb-pod spec: containers: - args: - mariadbd env: - name: MARIADB_ROOT_PASSWORD value: x image: docker.io/library/mariadb:10.11 name: some-mariadb ports: - containerPort: 3306 hostPort: 34891 volumeMounts: - mountPath: /var/lib/mysql name: mariadb_data-pvc volumes: - name: mariadb_data-pvc persistentVolumeClaim: claimName: mariadb_data
Create Kubernetes Deployment YAML with 3 replicas for the specified container.
$ podman kube generate --type deployment --replicas 3 dep-ct r # Save the output of this file and use kubectl create -f to import # it into Kubernetes. # # Created with podman-4.5.0-dev apiVersion: apps/v1 kind: Deployment metadata: creationTimestamp: "2023-03-27T20:45:08Z" labels: app: dep-ctr-pod name: dep-ctr-pod-deployment spec: replicas: 3 selector: matchLabels: app: dep-ctr-pod template: metadata: annotations: io.podman.annotations.ulimit: nofile=524288:524288,nproc=127332:127332 creationTimestamp: "2023-03-27T20:45:08Z" labels: app: dep-ctr-pod name: dep-ctr-pod spec: containers: - command: - top image: docker.io/library/alpine:latest name: dep-ctr
Create Kubernetes Pod YAML for the specified container with the host directory /home/user/my-data bind-mounted onto the container path /volume.
$ podman kube generate my-container-with-bind-mounted-data # Save the output of this file and use kubectl create -f to import # it into Kubernetes. # # Created with podman-3.1.0-dev apiVersion: v1 kind: Pod metadata: creationTimestamp: "2021-03-18T16:26:08Z" labels: app: my-container-with-bind-mounted-data name: my-container-with-bind-mounted-data spec: containers: - command: - /bin/sh image: docker.io/library/alpine:latest name: test-bind-mount volumeMounts: - mountPath: /volume name: home-user-my-data-host restartPolicy: Never volumes: - hostPath: path: /home/user/my-data type: Directory name: home-user-my-data-host
Create Kubernetes Pod YAML for the specified container with named volume priceless-data mounted onto the container path /volume.
$ podman kube generate my-container-using-priceless-data # Save the output of this file and use kubectl create -f to import # it into Kubernetes. # # Created with podman-3.1.0-dev apiVersion: v1 kind: Pod metadata: creationTimestamp: "2021-03-18T16:26:08Z" labels: app: my-container-using-priceless-data name: my-container-using-priceless-data spec: containers: - command: - /bin/sh image: docker.io/library/alpine:latest name: test-bind-mount volumeMounts: - mountPath: /volume name: priceless-data-pvc restartPolicy: Never volumes: - name: priceless-data-pvc persistentVolumeClaim: claimName: priceless-data
Create Kubernetes Pod YAML for the specified pod and include a service.
$ sudo podman kube generate -s demoweb # Save the output of this file and use kubectl create -f to import # it into Kubernetes. # # Created with podman-0.12.2-dev apiVersion: v1 kind: Pod metadata: creationTimestamp: 2018-12-18T15:16:06Z labels: app: demoweb name: demoweb-libpod spec: containers: - command: - python3 - /root/code/graph.py image: quay.io/baude/demoweb:latest name: practicalarchimedes tty: true workingDir: /root/code --- apiVersion: v1 kind: Service metadata: creationTimestamp: 2018-12-18T15:16:06Z labels: app: demoweb name: demoweb-libpod spec: ports: - name: "8050" nodePort: 31269 port: 8050 targetPort: 0 selector: app: demoweb type: NodePort status: loadBalancer: {}
See Also
podman(1), podman-container(1), podman-pod(1), podman-kube-play(1), podman-kube-down(1)
History
December 2018, Originally compiled by Brent Baude (bbaude at redhat dot com)
Referenced By
podman-generate(1), podman-kube(1), podman-kube-apply(1), podman-kube-down(1), podman-kube-play(1).
The man pages docker-generate-kube(1), docker-kube-generate(1) and podman-generate-kube(1) are aliases of podman-kube-generate(1).