C++ Learning Notes. 1. Knowledge Map. Architecture Program Language classification. Generic Programming

K8S network is divided into 3 levels. From inside to outside, there are 3 types: 1) Container Network. 2) Intra-Cluster Network. 3) External Cluster Network. Below is the details, 1. Container Network Docker networking is limited within the host itself. By default, it creates a virtual bridge named docker0 and for each container it allocates a virtual ethane which get attached to the bridge docker0. So, in Docker two containers can communicate with each other if they resident on the same host.

1. About K8S health check Health check is the important feature of the k8s orchestrating. K8s can monitor those containers and automatically restart them if they fail. If the container’s main process crashes, the k8s will restart the container. Also if your application has a bug that causes it to crash every once in a while, k8s will restart it automatically.There are two kinds of ways for health check. Liveness and Readiness.

1. How to write the YAML 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deploymnet spec: replicas: 3 selector: matchLabels: app: web_server template: metadata: labels: app: web_server spec: containers: - name: nginx image: nginx:1.7.9 Okay, Let us analysis this YAML sample. It used the indentation to represent the layer. Every layer was dependent and called each other.

A Deployment provides declarative updates for Pods and ReplicaSets. We can make use of many Deployment features. This chapter covers Updating a Deployment, rolling back a Deployment, Scalling a Deployment, Pausing and Resuming a Deployment and Deployment Status. First, we create a Deployment. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deploymnet spec: replicas: 3 selector: matchLabels: app: web_server template: metadata: labels: app: web_server spec: containers: - name: nginx image: nginx:1.

1. emptyDir It’s the basis of Volume. The life cycle depends on the Pod. The volume will be removed when the related Pod was removed. So we can think of it as the path of the Pod. All the containers of the pod share this voiume. Let’s show how to setup the volume configure. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 apiVersion: v1 kind: Pod metadata: name: producer-consumer spec: containers: - image: busybox name: producer volumeMounts: - mountPath: /producer_dir name: shared-volume args: - /bin/sh - -c - echo "hello world" > /producer_dir/hello; sleep 30000 - image: busybox name: consumer volumeMounts: - mountPath: /consumer_dir name: shared-volume args: - /bin/sh - -c - cat /consumer_dir/hello; sleep 30000 volumes: - name: shared-volume emptyDir: {} The above file is about configure the volume practice.