Introduction to Kubernetes

Editor's Notes

1. PodCIDR represents the pod IP range assigned to the node External ID of the node assigned by some machine database (e.g. a cloud provider)
2. type Registry interface { List() (currentMinions []string, err error) Insert(minion string) error Delete(minion string) error Contains(minion string) (bool, error) }
3. const ( // PodPending means the pod has been accepted by the system, but one or more of the containers // has not been started. This includes time before being bound to a node, as well as time spent // pulling images onto the host. // PodRunning means the pod has been bound to a node and all of the containers have been started. // At least one container is still running or is in the process of being restarted. // PodSucceeded means that all containers in the pod have voluntarily terminated // with a container exit code of 0, and the system is not going to restart any of these containers. // PodFailed means that all containers in the pod have terminated, and at least one container has // terminated in a failure (exited with a non-zero exit code or was stopped by the system). // PodUnknown means that for some reason the state of the pod could not be obtained, typically due // to an error in communicating with the host of the pod. ) HostNetwork : Uses the host's network namespace. If this option is set, the ports that will be used must be specified. Optional: Default to false.
4. ListPods(selector labels.Selector) ([]api.Pod, error) // Watch for new/changed/deleted pods WatchPods(resourceVersion uint64) (watch.Interface, error) // Get a specific pod GetPod(podID string) (*api.Pod, error) // Create a pod based on a specification, schedule it onto a specific machine. CreatePod(machine string, pod api.Pod) error // Update an existing pod UpdatePod(pod api.Pod) error // Delete an existing pod DeletePod(podID string) error
5. // Service is a named abstraction of software service (for example, mysql) consisting of local port // (for example 3306) that the proxy listens on, and the selector that determines which pods // will answer requests sent through the proxy. type Service struct { JSONBase `json:",inline" yaml:",inline"` Port int `json:"port,omitempty" yaml:"port,omitempty"` // This service's labels. Labels map[string]string `json:"labels,omitempty" yaml:"labels,omitempty"` // This service will route traffic to pods having labels matching this selector. Selector map[string]string `json:"selector,omitempty" yaml:"selector,omitempty"` CreateExternalLoadBalancer bool `json:"createExternalLoadBalancer,omitempty" yaml:"createExternalLoadBalancer,omitempty"` // ContainerPort is the name of the port on the container to direct traffic to. // Optional, if unspecified use the first port on the container. ContainerPort util.IntOrString `json:"containerPort,omitempty" yaml:"containerPort,omitempty"` }
6. ListServices() (api.ServiceList, error) CreateService(svc api.Service) error GetService(name string) (*api.Service, error) DeleteService(name string) error UpdateService(svc api.Service) error UpdateEndpoints(e api.Endpoints) error
7. type Kubelet struct { hostname string dockerClient DockerInterface rootDirectory string podWorkers podWorkers resyncInterval time.Duration // Optional, no events will be sent without it etcdClient tools.EtcdClient // Optional, no statistics will be available if omitted cadvisorClient CadvisorInterface // Optional, defaults to simple implementaiton healthChecker health.HealthChecker // Optional, defaults to simple Docker implementation dockerPuller DockerPuller // Optional, defaults to /logs/ from /var/log logServer http.Handler // Optional, defaults to simple Docker implementation runner ContainerCommandRunner }
8. type Kubelet struct { hostname string dockerClient DockerInterface rootDirectory string podWorkers podWorkers resyncInterval time.Duration // Optional, no events will be sent without it etcdClient tools.EtcdClient // Optional, no statistics will be available if omitted cadvisorClient CadvisorInterface // Optional, defaults to simple implementaiton healthChecker health.HealthChecker // Optional, defaults to simple Docker implementation dockerPuller DockerPuller // Optional, defaults to /logs/ from /var/log logServer http.Handler // Optional, defaults to simple Docker implementation runner ContainerCommandRunner }