table of Contents
Kubernetes Profile
1. What is Kubernetes
Kubernetes (commonly referred K8s, K8s 8 is a letter "ubernete" is replaced with the abbreviation "8") is a container to the central infrastructure, it may be implemented on a scheduled physical cluster or cluster and virtual machines running the container, provided container automatically deploy, scale and manage open source platform. To meet the needs of some common applications in a production environment: a copy of the application example, the level of the automatic extension, naming and discovery, load balancing, rolling upgrades, resource monitoring.
2. History of development Kubernetes
Kubernetes (Greek "helmsman" or "Pilot") was founded by Joe Beda, Brendan Burns and Craig McLuckie, by other Google engineers, including Brian Grant and Tim Hockin creation were joined by Google first announced in 2014. Its development and design of Borg deeply influenced by Google system, before many of its top contributors also Borg system developers. In internal Google, Kubernetes the original code used to be Seven, namely Star Trek friendly Borg (Borg) role. Kubernetes identifies seven spokes in the wheel is the code name of the project to pay tribute.
Kubernetes v1.0 released on July 21, 2015. With the v1.0 release, Google Linux Foundation, set up in cooperation with the Cloud Native Computing Foundation (CNCF) and the Kubernetes as seed technology to provide.
Rancher Labs release contains Kubernetes of its Rancher container management platform. Kubernetes also a lot of other company's products are used, such as Red Hat in OpenShift products, CoreOS of Tectonic products, as well as IBM's IBM private cloud products.
3. Kubernetes Features
1, portable: support public cloud, private cloud, hybrid cloud, cloud multiple (multi-cloud)
2, can be extended: a modular, plug-in technology, can be mounted, may be combined
3, automation: automatic deployment, automatic restart, automatic replication, automatic retractable / expansion
4, quickly deploy applications, rapid expansion application
5, seamless new application functionality
6, save resources, optimize the use of hardware resources
4.Kubernetes core components
Kubernetes follow the Master-Slave Architecture . Kubernetes components may be divided into a single management node and control components of the planar portion.
Kubernetes Master is the primary control unit of the cluster, to manage their workloads and direct communication of the whole system. Kubernetes control plane by a respective process, each component can run on a single master node may support high-availability clusters running on multiple nodes of the master.
Kubernetes mainly consists of the following core components:
| Component Name | Explanation |
|---|---|
| etcd | Save the state of the entire cluster; |
| apiserver | It provides the only entrance resources operations, and to provide authentication, authorization, access control, API registration and discovery mechanisms; |
| controller manager | Responsible for maintaining the state of the cluster, such as fault detection, automatic extension, rollover, etc.; |
| scheduler | Responsible for scheduling resources according to a predetermined scheduling policy to schedule the Pod corresponding machine; |
| omelet | Responsible for maintaining the life cycle of the container, is also responsible for managing Volume (CVI) and network (CNI) of; |
| Container runtime | Responsible for image management and Pod and containers actually run (CRI); |
| kube-proxy | Service is responsible for providing internal cluster service discovery and load balancing; |
FIG structural core components
1.master node workflow diagram:
2.node node port mapping:
3.pod work flow chart:
In addition to the core components, there are some recommended Add-ons:
| Component Name | Explanation |
|---|---|
| dome-dns | DNS is responsible for providing services for the entire cluster |
| Ingress Controller | For service providers outside the network entrance |
| Heapster | Provide resource monitoring |
| Dashboard | It provides a GUI |
| Federation | It provides cluster across the available area |
| Fluentd-elasticsearch | It provides cluster log collection, storage and query |