Insider of container network hard core technology (7) sailing on the sea depends on the helmsman

Let's summarize based on docker The container network of the engine ：

Every docker The container needs to be connected to the network , In order to provide external services , Otherwise, its existence has no meaning . therefore , On each host by default , There is one docker0 bridge , All containers are connected to this bridge by default , As shown in the figure below ：

Pictured ,172.17.0.2 This container runs ubuntu example , and 172.17.0.3 This container runs nginx example , Both can be through docker0 Interworking .

For accessing a network other than the host , Need to pass through NAT：

Of course , External access to the container inside the host , It also needs to go through NAT.

For mutual visits between two host computers , You can use swarm Implementation is based on VXLAN Interworking of tunnels ：

With these basic container network mechanisms , We can build a container based external service system .

However , Only docker engine , Is not enough ……

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We know , It is China's hundreds of millions of workers , Unite closely , Just defeated three mountains 、 The United Nations 、 Schistosomiasis and novel coronavirus .

We also know that , stay linux + docker In the system , Create a container 、 Destruction of the container 、 Connect the container to the network 、 Monitor container performance and other operations , All need to be done manually .

If a single container cannot meet the requirements of performance or function , Nor can it be expanded automatically by automatic means , Or couple and associate multiple containers with different functions .

Only let the container unite , To play a greater role ！

DOCKERS OF THE WORLD, UNITE!

A ghost , The ghost of cloud primordial , Quietly wandering in the Internet field of China and the United States, where the productivity is the most developed ——

Engineers created a container layout platform ：Kubernetes.

Kubernetes The literal meaning of is “ helmsman ”.

Kubernetes Container resources can be automatically scheduled , Create containers 、 Access network 、 Expansion and destruction , combination Harbor Mirror warehouse 、Istio API gateway 、Prometheus Performance monitoring 、Jenkins Build assembly lines and other components , It can realize from code submission to automatic deployment CI/CD( Continuous integration / Continuous development ), Make the container really drive into the blue ocean ——

Sailing in the sea depends on the helmsman ！

“ helmsman ” kubernetes The architecture of is as follows ：

In such a complex architecture , At present, we only need to master ：

1. Kubernetes The container resource allocation unit of is pod, One pod There can be multiple containers in , But yes pod The outside presents as a whole ( One IP Address );
2. Kubernetes The container operation carrier of is node, One node Can run multiple Pod.node It has its own operating system ( It's usually Linux).

We can node Analogy to the host in the virtual machine world ,pod The analogy is... In the virtual machine world VM.

The following discussion is based on this .

Please look forward to the next issue ——