Kubernetes allows for extensions to its architecture in the form of 3rd party resources: http://kubernetes.io/docs/user-guide/thirdpartyresources/. KubeVirt represents virtual machines as 3rd party resources and manages changes to libvirt domains based on the state of those resources.
- virt-api: This component provides a HTTP RESTful entrypoint to manage the virtual machines within the cluster.
- virt-controller: This component manages the state of each VM within the Kubernetes cluster.
- virt-handler: This is a daemon that runs on each Kubernetes node. It is responsible for monitoring the state of VMs according to Kubernetes and ensuring the corresponding libvirt domain is booted or halted accordingly.
- virt-launcher: This component is a place-holder, one per running VM. Its job is to remain running as long as the VM is defined. This simply prevents a crash-loop state.
- ha-proxy: This daemon proxies connections from 192.168.200.2 to the running master node--making it possible to establish connections in a consistent manner.
cluster/sync.sh: After deploying a fresh vagrant environment, or after making changes to code in this tree, this script will sync the Pods and DaemonSets in the running KubeVirt environment with the state of this tree.cluster/kubectl.sh: This is a wrapper around Kubernete's kubectl command so that it can be run directly from this checkout without logging into a node.cluster/sync_config.sh: This script will contact the master node and collect its config and kubectl. It is called by sync.sh so does not generally need to be run separately.cluster/vm-isolation-check.sh: This script will run a series of tests to ensure the system is set up correctly.