k8s by the master node of the cluster generally, node node, ETCD database, stored independently composition.
Total production environment, master station has at least three sections, ETCD may be mounted on a separate server, it may be installed on the master node. etcd is to save the state of the cluster database.
k8s minimum logical unit is scheduled pod, the pod by one or more service container and a root container (the Pause container) composition, there are four categories pod:
. 1, the system in the pod space kube-system
2, in the manual master pod created
3, each pod on the master controller automatically creates
a static pod 4, on the master node is not manually created management
The main components of the master node comprising:
. 1, Kube-apiserver: cluster control entrance, and HTTP REST service
2, kube-controller-manager: Kubernetes cluster automation control center for all resource objects
3, kube-scheduler: responsible for the Pod scheduling
4, etcd database (it can also be installed on a separate server)
The main components on node node includes:
1, kubelet: responsible for creating the Pod, start, monitor, restart, job destruction, etc., and in collaboration with the Master node
2, kube-proxy: enable communication and load balancing Kubernetes Service of
3, container engine (Container runtime) as docker
All nodes installed plugins are required:
1, DNS plug coredns
2, such as the network plug flannel
Controller Manager plurality of management controllers:
. 1, the controller pod
2, node controller
3, namespace controller
4, service controller
5, endpoint controller
6, resourcequota controller
pod controller Category:
1、ReplicationController
2、ReplicaSet
3、Deployment
4、StatefulSet
5、DaemonSet
6、Job,Cronjob
7、HPA
k8s resource objects include:
1, the workload classes: pod and the pod controller
2, and the load balancing classes found:-Service, Endpoint, Ingress
. 3, and the configuration storage class: Volume, ConfigMap
. 4, the cluster categories: namespace, node, Role, clusterrole, rolebinding, clusterrolebinding
. 5, the metadata categories: HPA, pod template, limitrange
k8s network has three layers:
1, the network node
2, service network (cluster network)
3, POD network
k8s a communication:
1, the communication between the containers within the same pod
2, the communication between the pod
communication between. 3, pod and service
communication between 4 and external pod client