dmaizel / kata-operator

An operator to enhance an Openshift/Kubernetes cluster to support running Kata containers

ℹ️ If you are using OCP 4.6 please follow this README

Kata Operator

An operator to perform lifecycle management (install/upgrade/uninstall) of Kata Runtime on Openshift as well as Kubernetes cluster.

Installing the Kata Runtime on the Cluster using Kata Operator

Openshift

1. Make sure that oc is configured to talk to the cluster

2. Clone the Kata Operator repository and check out the branch matching with the Openshift version. e.g. If you are running Openshift 4.7 then,

   git clone https://github.com/openshift/kata-operator 
   git checkout -b master --track origin/master
   

3. Install the Kata Operator on the cluster,

   make install && make deploy IMG=quay.io/isolatedcontainers/kata-operator:4.7
   oc adm policy add-scc-to-user privileged -z default -n kata-operator-system
   

4. To begin the installation of the kata runtime on the cluster,

   oc create -f config/samples/kataconfiguration_v1_kataconfig.yaml
   

   Please follow this section if you wish to install the Kata Runtime only on selected worker nodes.

Monitoring the Kata Runtime Installation

Watch the description of the Kataconfig custom resource

oc describe kataconfig example-kataconfig

and look at the field 'Completed nodes' in the status. If the value matches the number of worker nodes the installation is completed.

Runtime Class

Once the kata runtime binaries are successfully installed on the intended workers, Kata Operator will create a runtime class kata. This runtime class can be used to deploy the pods that will use the Kata Runtime.

Run an Example Pod using the Kata Runtime

oc apply -f config/samples/example-fedora.yaml

Selectively Install the Kata Runtime on Specific Workers

Openshift

1. edit the custom resource file config/samples/kataconfiguration_v1_kataconfig.yaml and uncomment the kata pool selector fields in the spec as follows,

   apiVersion: kataconfiguration.openshift.io/v1alpha1
   kind: KataConfig
   metadata:
     name: example-kataconfig
   spec:
     kataConfigPoolSelector:
       matchLabels:
          custom-kata1: test

   If you wish, you can change the label "custom-kata1:test" to something of your choice.

2. Apply the chosen label to the desired nodes. e.g. oc label node <worker_node_name> custom-kata1=test

3. Create the custom resource to start the installation,

   oc create -f config/samples/kataconfiguration_v1_kataconfig.yaml
   

Uninstall

Openshift

oc delete kataconfig <KataConfig_CR_Name>

e.g.

oc delete kataconfig example-kataconfig

Troubleshooting

Openshift

1. During the installation you can watch the values of the kataconfig CR. Do watch oc describe kataconfig example-kataconfig.
2. To check if the nodes in the machine config pool are going through a config update watch the machine config pool resource. For this do watch oc get mcp kata-oc
3. Check the logs of the kata-operator controller pod to see detailled messages about what the steps it is executing. To find out the name of the controller pod, oc get pods -n kata-operator-system | grep kata-operator-controller-manager and then monitor the logs of the container manager in that pod.

Components

Openshift

The kata-operator uses three containers:

Container image name	Description	Container repository
kata-operator	It contains the controller part of the operator that watches and manages the kataconfig custom resource. It runs as a cluster scoped container. The operator itself is build with operator-sdk.	https://quay.io/isolatedcontainers/kata-operator
kata-operator-daemon	The daemon part of the operator that runs on the nodes and performs the actual installation. It pulls down the container kata-operator-payload image. Dockerfile and other content can be found in images/daemon/ subdirectory of this github repository	https://quay.io/isolatedcontainers/kata-operator-daemon
kata-operator-payload	The payload that is used by the daemon to install the kata binaries and dependencies (like e.g. QEMU). It's a container image with (currently) RPMs in it that will be installed on the chosen worker nodes by the daemon. Dockerfile and other content can be found in images/payload subdirectory of this github repository.	https://quay.io/isolatedcontaineres/kata-operator-payload

Upgrading Kata

Openshift

Not implemented yet

Kubernetes

Not implemented yet

Build from source

1. Install operator-sdk version 1.0 or above
2. make docker-build docker-push IMG=quay.io//kata-operator: