云原生Java架构实战 K8s+Docker+KubeSphere+DevOps（上）

云原生Java架构 K8s+Docker+KubeSphere+DevOps

云平台
- 私有网络VPC
- VPC的子网计算
- VPC的交换机
- 重要概念
容器化
- docker概念
- 青云服务器
- - centos安装docker
- docker实战
- docker进阶
- - 部署redis
  - 创建Java应用
Kubernetes
- 基础概念
- - 简介
  - 集群的方式
- 集群搭建
- - 创建服务器
  - docker容器化环境安装
  - 预备环境创建
  - 安装集群三大件
  - 使用kubeadm引导启动集群
  - 部署dashboard
- 核心实战
- - 操作NameSpace
  - 理解Pod
  - 可视化方式操作pod和pod细节
  - 使用Deployment部署应用
  - Deployment扩缩容
  - 自愈&故障转移
  - 服务网络
  - Ingress
  - - Ingress的使用
- 存储抽象
- - 环境准备
  - PV&PVC
  - ConfigMap
  - Secret
end

简介：摘自尚硅谷雷锋阳老师的语雀文档

云平台

学会使用按量付费的云服务器，开发测试性价比高

私有网络VPC

和网络有关的概念，如何在云服务器开通一个集群

一个云服务器有两个IP：公网IP和私网IP

公网IP：对外暴露资源的访问，可能会发生改变，按量付费服务器每次启动可能都会发生改变
私网IP：服务器内部网卡使用的IP，需要固定不变，集群内部交互用

VPC的子网计算

VPC：私有网络、专有网络

网段的概念

将IP地址转化为二进制就是如下，每个段有八位二进制，16掩码表示掩去前16位，只后16位变化，而8位最大二进制 11111111转化为10 进制就是 256 ，而IP包括一个零那就是255，所以此网段的变化为
192.168.0.0 ~ 192.168.255.255 有 65536 个IP

通过子网计算，实际可用为65534个

VPC的交换机

因为专有网络的可用IP太多了不好区分，单16位掩码的IP就有65534个，所以交换机的作用是用来规定专有网络下的哪些IP能用，避免专有网络使用太过混乱
在创建专有网络时同时制定或创建交换机，如下图的设定，表示创建24位掩码，指定第三段的号段，那么可用IP就在第4号段变化，将可用IP由65534个缩小到了252个，避免了混乱

重要概念

不同VPC网络下，即使私有网络IP相同，他们之间内部是无法平通的，所以一个VPC相当于一个局域网的隔离，

容器化 docker概念

差异化保存

资源隔离
● cpu、memory资源隔离与限制
● 访问设备隔离与限制
● 网络隔离与限制
● 用户、用户组隔离限制

架构

Docker_Host：
○ 安装Docker的主机
Docker Daemon：
○ 运行在Docker主机上的Docker后台进程
Client：
○ 操作Docker主机的客户端（命令行、UI等）
Registry：
○ 镜像仓库
○ Docker Hub
Images：
○ 镜像，带环境打包好的程序，可以直接启动运行
Containers：
○ 容器，由镜像启动起来正在运行中的程序

青云服务器 centos安装docker

1、移除以前docker相关包

sudo yum remove docker 
                  docker-client 
                  docker-client-latest 
                  docker-common 
                  docker-latest 
                  docker-latest-logrotate 
                  docker-logrotate 
                  docker-engine

2、配置yum源

sudo yum install -y yum-utils
sudo yum-config-manager 
--add-repo 
http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

3、安装docker

sudo yum install -y docker-ce docker-ce-cli containerd.io


#以下是在安装k8s的时候使用 指定版本
yum install -y docker-ce-20.10.7 docker-ce-cli-20.10.7  containerd.io-1.4.6

4、启动和开机启动

systemctl enable docker --now

5、配置加速

sudo mkdir -p /etc/docker
sudo tee /etc/docker/daemon.json <<-'EOF'
{
  "registry-mirrors": ["https://vgcihl1j.mirror.aliyuncs.com"]
}
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

docker实战

1、找镜像

docker pull nginx  #下载最新版

镜像名:版本名（标签）

docker pull nginx:1.20.1


docker pull redis  #下载最新
docker pull redis:6.2.4

## 下载来的镜像都在本地
docker images  #查看所有镜像

redis = redis:latest

docker rmi 镜像名:版本号/镜像id

2、启动容器

启动nginx应用容器，并映射88端口，测试的访问

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

【docker run  设置项   镜像名  】 镜像启动运行的命令（镜像里面默认有的，一般不会写）

# -d：后台运行
# --restart=always: 开机自启
docker run --name=mynginx   -d  --restart=always -p  88:80   nginx
# 端口映射   [-p 主机端口:容器端口]



# 查看正在运行的容器
docker ps
# 查看所有
docker ps -a
# 删除停止的容器
docker rm  容器id/名字
docker rm -f mynginx   #强制删除正在运行中的

#停止容器
docker stop 容器id/名字
#再次启动
docker start 容器id/名字

#应用开机自启
docker update 容器id/名字 --restart=always

3、进入容器修改内容

[root@i-r686cdnl ~] docker ps
ConTAINER ID   IMAGE     COMMAND                  CREATED         STATUS         PORTS                               NAMES
33040453a360   nginx     "/docker-entrypoint.…"   2 minutes ago   Up 2 minutes   0.0.0.0:88->80/tcp, :::88->80/tcp   mynginx
[root@i-r686cdnl ~] docker exec -it 33040453a360 /bin/sh
root@33040453a360:/bin] cd /usr/share/nginx/html
root@33040453a360:/usr/share/nginx/html] echo "hello atguigu" > index.html

docker run --name=mynginx   
-d  --restart=always 
-p  88:80 
-v /data/html:/usr/share/nginx/html:ro  
nginx

# -v 主机目录:容器目录:读写权限
# 修改页面只需要去 主机的 /data/html

4、提交改变
将指定容器提交成新容器

[root@i-r686cdnl ~]# docker ps
ConTAINER ID   IMAGE     COMMAND                  CREATED          STATUS          PORTS                               NAMES
33040453a360   nginx     "/docker-entrypoint.…"   12 minutes ago   Up 12 minutes   0.0.0.0:88->80/tcp, :::88->80/tcp   mynginx
[root@i-r686cdnl ~]# docker commit --help

Usage:  docker commit [OPTIONS] ConTAINER [REPOSITORY[:TAG]]

Create a new image from a container's changes

Options:
  -a, --author string    Author (e.g., "John Hannibal Smith ")
  -c, --change list      Apply Dockerfile instruction to the created image
  -m, --message string   Commit message
  -p, --pause            Pause container during commit (default true)
[root@i-r686cdnl ~] docker commit -a "作者" -m "描述" 33040453a360 gugunginx:v1.0
sha256:50eecfacab35a36f8dfd3aefd205e04dfe5742e590fdc6061aaf490ecedfa3bf

[root@i-r686cdnl ~] docker images
REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
gugunginx    v1.0      50eecfacab35   6 seconds ago   133MB
nginx        latest    87a94228f133   9 days ago      133MB

镜像传输

# 将镜像保存成压缩包
docker save -o abc.tar guignginx:v1.0

# 别的机器加载这个镜像
docker load -i abc.tar


# 离线安装

5、推送远程仓库
推送镜像到docker hub；应用市场

docker tag local-image:tagname new-repo:tagname
docker push new-repo:tagname


# 把旧镜像的名字，改成仓库要求的新版名字
docker tag guignginx:v1.0 leifengyang/guignginx:v1.0

# 登录到docker hub
docker login       


docker logout（推送完成镜像后退出）

# 推送
docker push leifengyang/guignginx:v1.0


# 别的机器下载
docker pull leifengyang/guignginx:v1.0

6、补充

docker logs 容器名/id   排错

docker exec -it 容器id /bin/bash


# docker 经常修改nginx配置文件
docker run -d -p 80:80 
-v /data/html:/usr/share/nginx/html:ro 
-v /data/conf/nginx.conf:/etc/nginx/nginx.conf 
--name mynginx-02 
nginx


#把容器指定位置的东西复制出来 
docker cp 5eff66eec7e1:/etc/nginx/nginx.conf  /data/conf/nginx.conf
#把外面的内容复制到容器里面
docker cp  /data/conf/nginx.conf  5eff66eec7e1:/etc/nginx/nginx.conf

docker进阶部署redis

部署一个Redis+应用，尝试应用操作Redis产生数据
注意先创建好主机的文件挂载目录和配置文件

mkdir -p /data/redis/
vi redis.conf 
appendonly yes

-------------------------------

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

#redis使用自定义配置文件启动

docker run 
-v /data/redis/redis.conf:/etc/redis/redis.conf 
-v /data/redis/data:/data 
-d --name myredis  
-p 6379:6379 
redis:latest  redis-server /etc/redis/redis.conf #启动时额外命令 redis-server 以/etc/redis/redis.conf 配置文件加载启动

设置redis密码登录

vi redis.conf 
requirepass 123xxx
docker restart myredis #重启redis

创建Java应用

1、用redis简单的统计功能

@RestController
public class CounterController {

    @Autowired
    StringRedisTemplate redisTemplate;

    @GetMapping("/hello")
    public String count(){

        Long increment = redisTemplate.opsForValue().increment("count-people");
        return "有"+ increment +" 访问了页面";
    }

}

2、将应用打包成镜像

以前：Java为例

SpringBoot打包成可执行jar
把jar包上传给服务
服务器运行java -jar

现在：所有机器都安装Docker，任何应用都是镜像，所有机器都可以运行

3、怎么打包-Dockerfile

FROM openjdk:8-jdk-slim	#基础运行环境,相当去掉了 duoker pull
LABEL maintainer=leifengyang #作者

COPY target#&/' /etc/fstab

#允许 iptables 检查桥接流量
cat < 
安装集群三大件 
安装kubelet、kubeadm、kubectl 
# 设置镜像源
cat < 
使用kubeadm引导启动集群 
1、提前下载各个机器需要的镜像，避免因网络原因造成的安装失败 
# 生成一个sh文件，循环下载定义的镜像
sudo tee ./images.sh <<-'EOF'
#!/bin/bash
images=(
kube-apiserver:v1.20.9
kube-proxy:v1.20.9
kube-controller-manager:v1.20.9
kube-scheduler:v1.20.9
coredns:1.7.0
etcd:3.4.13-0
pause:3.2
)
for imageName in ${images[@]} ; do
docker pull registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/$imageName
done
EOF
   
# 给文件执行权限并执行
chmod +x ./images.sh && ./images.sh
 
2、初始化主节点 
#所有机器添加master域名映射，以下需要修改为自己的master节点的私网IP
# 让所有节点知道主节点的位置IP
echo "172.31.0.2  cluster-endpoint" >> /etc/hosts



#主节点初始化
kubeadm init 
--apiserver-advertise-address=172.31.0.2 
--control-plane-endpoint=cluster-endpoint 
--image-repository registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images 
--kubernetes-version v1.20.9 
--service-cidr=10.96.0.0/16 
--pod-network-cidr=192.168.0.0/16

#所有网络范围不重叠

 
初始化后返回的信息 
Your Kubernetes control-plane has initialized successfully!

# 第一步 要使用这个集群还要执行下面这些步骤。需要马上执行
To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config


Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf
  
# 还应该再来部署一个pod网络插件,这个插件将集群之间的机器打通互相通讯
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

# 你可以加入任意多的主节点
You can now join any number of control-plane nodes by copying certificate authorities
and service account keys on each node and then running the following as root:

  kubeadm join cluster-endpoint:6443 --token 2n4gns.e3n0mqlip1nmbbqa 
    --discovery-token-ca-cert-hash sha256:786bc6e4ac9d96e6d6764d94b16e4cd40e599669e4824ebba5a7eba31bb2a983 
    --control-plane 

# 还可以加入任意多的工作节点，运行下面的kubeadm加入子节点
Then you can join any number of worker nodes by running the following on each as root:

kubeadm join cluster-endpoint:6443 --token epjqlx.25mfge9y4rgw1n4o 
    --discovery-token-ca-cert-hash sha256:5298e8db61faebe5eca8bfc5ec788d5f9bb4bad16dbe924027d33c05416c3738
 
运行上面第一步，完成主节点创建 
现在能用到的一些命令 
#查看集群所有节点
kubectl get nodes

#根据配置文件，给集群创建资源
kubectl apply -f xxxx.yaml

#查看集群部署了哪些应用？
docker ps   ===   kubectl get pods -A
# 运行中的应用在docker里面叫容器，在k8s里面叫Pod
kubectl get pods -A
 
3、安装网络组件 
curl https://docs.projectcalico.org/manifests/calico.yaml -O

kubectl apply -f calico.yaml
 
4、加入node节点
 在子节点，运行上面初始化master节点时生成的命令，这个命令24小时内有效 
kubeadm join cluster-endpoint:6443 --token 2n4gns.e3n0mqlip1nmbbqa 
    --discovery-token-ca-cert-hash sha256:786bc6e4ac9d96e6d6764d94b16e4cd40e599669e4824ebba5a7eba31bb2a983 
 
若令牌过期，主节点创建新令牌
 kubeadm token create --print-join-command 
等待一会查看节点准备状况，至此k8s集群准备就绪 
[root@k8s-master ~] kubectl get nodes
NAME         STATUS   ROLES                  AGE   VERSION
k8s-master   Ready    control-plane,master   34m   v1.20.9
k8s-node1    Ready                     83s   v1.20.9
k8s-node2    Ready                     78s   v1.20.9
 
部署dashboard 
1、部署 
kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.3.1/aio/deploy/recommended.yaml
 
# Copyright 2017 The Kubernetes Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR ConDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

apiVersion: v1
kind: Namespace
metadata:
  name: kubernetes-dashboard

---

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard

---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 443
      targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-certs
  namespace: kubernetes-dashboard
type: Opaque

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-csrf
  namespace: kubernetes-dashboard
type: Opaque
data:
  csrf: ""

---

apiVersion: v1
kind: Secret
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-key-holder
  namespace: kubernetes-dashboard
type: Opaque

---

kind: ConfigMap
apiVersion: v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard-settings
  namespace: kubernetes-dashboard

---

kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
rules:
  # Allow Dashboard to get, update and delete Dashboard exclusive secrets.
  - apiGroups: [""]
    resources: ["secrets"]
    resourceNames: ["kubernetes-dashboard-key-holder", "kubernetes-dashboard-certs", "kubernetes-dashboard-csrf"]
    verbs: ["get", "update", "delete"]
    # Allow Dashboard to get and update 'kubernetes-dashboard-settings' config map.
  - apiGroups: [""]
    resources: ["configmaps"]
    resourceNames: ["kubernetes-dashboard-settings"]
    verbs: ["get", "update"]
    # Allow Dashboard to get metrics.
  - apiGroups: [""]
    resources: ["services"]
    resourceNames: ["heapster", "dashboard-metrics-scraper"]
    verbs: ["proxy"]
  - apiGroups: [""]
    resources: ["services/proxy"]
    resourceNames: ["heapster", "http:heapster:", "https:heapster:", "dashboard-metrics-scraper", "http:dashboard-metrics-scraper"]
    verbs: ["get"]

---

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
rules:
  # Allow Metrics Scraper to get metrics from the Metrics server
  - apiGroups: ["metrics.k8s.io"]
    resources: ["pods", "nodes"]
    verbs: ["get", "list", "watch"]

---

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: kubernetes-dashboard
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kubernetes-dashboard

---

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: kubernetes-dashboard
subjects:
  - kind: ServiceAccount
    name: kubernetes-dashboard
    namespace: kubernetes-dashboard

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: kubernetes-dashboard
  template:
    metadata:
      labels:
        k8s-app: kubernetes-dashboard
    spec:
      containers:
        - name: kubernetes-dashboard
          image: kubernetesui/dashboard:v2.3.1
          imagePullPolicy: Always
          ports:
            - containerPort: 8443
              protocol: TCP
          args:
            - --auto-generate-certificates
            - --namespace=kubernetes-dashboard
            # Uncomment the following line to manually specify Kubernetes API server Host
            # If not specified, Dashboard will attempt to auto discover the API server and connect
            # to it. Uncomment only if the default does not work.
            # - --apiserver-host=http://my-address:port
          volumeMounts:
            - name: kubernetes-dashboard-certs
              mountPath: /certs
              # Create on-disk volume to store exec logs
            - mountPath: /tmp
              name: tmp-volume
          livenessProbe:
            httpGet:
              scheme: HTTPS
              path: /
              port: 8443
            initialDelaySeconds: 30
            timeoutSeconds: 30
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      volumes:
        - name: kubernetes-dashboard-certs
          secret:
            secretName: kubernetes-dashboard-certs
        - name: tmp-volume
          emptyDir: {}
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule

---

kind: Service
apiVersion: v1
metadata:
  labels:
    k8s-app: dashboard-metrics-scraper
  name: dashboard-metrics-scraper
  namespace: kubernetes-dashboard
spec:
  ports:
    - port: 8000
      targetPort: 8000
  selector:
    k8s-app: dashboard-metrics-scraper

---

kind: Deployment
apiVersion: apps/v1
metadata:
  labels:
    k8s-app: dashboard-metrics-scraper
  name: dashboard-metrics-scraper
  namespace: kubernetes-dashboard
spec:
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      k8s-app: dashboard-metrics-scraper
  template:
    metadata:
      labels:
        k8s-app: dashboard-metrics-scraper
      annotations:
        seccomp.security.alpha.kubernetes.io/pod: 'runtime/default'
    spec:
      containers:
        - name: dashboard-metrics-scraper
          image: kubernetesui/metrics-scraper:v1.0.6
          ports:
            - containerPort: 8000
              protocol: TCP
          livenessProbe:
            httpGet:
              scheme: HTTP
              path: /
              port: 8000
            initialDelaySeconds: 30
            timeoutSeconds: 30
          volumeMounts:
          - mountPath: /tmp
            name: tmp-volume
          securityContext:
            allowPrivilegeEscalation: false
            readOnlyRootFilesystem: true
            runAsUser: 1001
            runAsGroup: 2001
      serviceAccountName: kubernetes-dashboard
      nodeSelector:
        "kubernetes.io/os": linux
      # Comment the following tolerations if Dashboard must not be deployed on master
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
      volumes:
        - name: tmp-volume
          emptyDir: {}
 
2、设置访问端口 
这里需要修改集群中的资源 
kubectl edit svc kubernetes-dashboard -n kubernetes-dashboard
 

 将type的值改为NodePort 
kubectl get svc -A |grep kubernetes-dashboard
## 找到端口，在安全组放行
 
 
访问： https://集群任意IP:端口 
3、创建访问账号 
#创建访问账号，准备一个yaml文件； vi dash.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard
 
kubectl apply -f dash.yaml
 
4、令牌访问 
#获取访问令牌
kubectl -n kubernetes-dashboard get secret $(kubectl -n kubernetes-dashboard get sa/admin-user -o jsonpath="{.secrets[0].name}") -o go-template="{{.data.token | base64decode}}"
 
复制返回的密钥就能登录 
核心实战 
操作NameSpace 
名称空间用来对资源隔离划分。默认只隔离资源，不隔离网络 
创建删除名称空间 
kubectl create ns hello
kubectl delete ns hello
 
通过文件创建名称空间 
apiVersion: v1
kind: Namespace
metadata:
  name: hello
 
通过文件创建的ns也通过文件删除 
kubectl apply -f hello.yml
kubectl delete -f hello.yml
 
理解Pod 
运行中的一组容器，Pod是kubernetes中应用的最小单位。一个pod中可能包含多个docker的容器 
查看pod能看到ready， 准备好的容器数量/总共的容器数量 

  
kubectl命令行方式创建第一个pod 
# 运行一个容器名字为mynginx 以 镜像nginx
kubectl run mynginx --image=nginx

# 查看default名称空间的Pod
kubectl get pod 
# 描述
kubectl describe pod 你自己的Pod名字
# 删除
kubectl delete pod Pod名字
# 查看Pod的运行日志
kubectl logs Pod名字

# 每个Pod - k8s都会分配一个ip
kubectl get pod -owide
# 使用Pod的ip+pod里面运行容器的端口
curl 192.168.169.136

# 集群中的任意一个机器以及任意的应用都能通过Pod分配的ip来访问这个Pod
 
以配置文件创建 
apiVersion: v1
kind: Pod
metadata:
  labels:
    run: mynginx
  name: mynginx
#  namespace: default
spec:
  containers:
  - image: nginx
    name: mynginx
 
kubectl apply -f 配置文件
kubectl delete -f 配置文件
 
可视化方式操作pod和pod细节 

 可视化控制台直接查看容器日志，和进入容器的内部相当于 docker exec -it /bin/bash 
# 进入容器，交互模式
kubectl exec -it myapp -- /bin/bash
 
# 每个Pod - k8s都会分配一个ip
kubectl get pod -owide
# 使用Pod的ip+pod里面运行容器的端口；集群内访问
curl 192.168.169.136
 
一个pod中启动两个容器 
apiVersion: v1
kind: Pod
metadata:
  labels:
    run: myapp
  name: myapp
spec:
  containers:
  - image: nginx
    name: nginx
  - image: tomcat:8.5.68
    name: tomcat
 

 此时的应用还不能外部访问，只能内部互相调用 
使用Deployment部署应用 
控制Pod，使Pod拥有多副本，自愈，扩缩容等能，
 即使主动执行删除pod指令kubectl delete pod xxx，集群也会恢复这个pod，这就是自愈 
# 清除所有Pod，比较下面两个命令有何不同效果？
kubectl run mynginx --image=nginx

kubectl create deployment mytomcat --image=tomcat:8.5.68
# 自愈能力

 
多副本部署 
kubectl create deployment my-dep --image=nginx --replicas=3
 
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: my-dep
  name: my-dep
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-dep
  template:
    metadata:
      labels:
        app: my-dep
    spec:
      containers:
      - image: nginx
        name: nginx
 
查看部署
 kubectl get deploy xxxx 
Deployment扩缩容 
kubectl scale --replicas=5 deployment/my-dep
 
自愈&故障转移 
启动了一个deployment有三个容器部署，其中node2两个，node1一个 
我们关机node2服务器，集群默认5分钟后才会做故障转移工作 
 
# 查看pod详细信息
kubectl get pod -owide

# 监控pod
kubectl get pod -w
 
4、滚动更新
 不停机更新，更改deploy对部署镜像，集群就会对deploy进行更新，老的镜像容器不回立马停机，而是等到新镜像容器启动成功后再替换掉老镜像容器，完成了不停机更新、滚动部署 
# 获取deploy部署的 yaml信息，详细查看具体用的什么镜像
kubectl get deploy my-dep -oyaml

# 修改dep的镜像，修改完成后立即开始滚动部署
kubectl set image deployment/my-dep nginx=nginx:1.16.1 --record


kubectl rollout status deployment/my-dep

 
5、版本回退 
#历史记录
kubectl rollout history deployment/my-dep


#查看某个历史详情
kubectl rollout history deployment/my-dep --revision=2

#回滚(回到上次)
kubectl rollout undo deployment/my-dep

#回滚(回到指定版本)
kubectl rollout undo deployment/my-dep --to-revision=2


# 获取部署的信息以yml输出 筛选image
kubectl get deploy/my-dep -oyaml|grep image


 
除了Deployment，k8s还有 StatefulSet 、DaemonSet 、Job 等 类型资源。我们都称为 工作负载。
 有状态应用使用 StatefulSet 部署，无状态应用使用 Deployment 部署
 https://kubernetes.io/zh/docs/concepts/workloads/controllers/ 
其他工作负载 
 
服务网络 
Service 
 
将一组 Pods 公开为网络服务的抽象方法。 
#暴露Deploy 指定外部端口8000映射至集群内部端口80
kubectl expose deployment my-dep --port=8000 --target-port=80 --type=ClusterIP
# 查询service暴露的ip
kubectl get svc


#使用标签检索Pod
kubectl get pod -l app=my-dep
 
服务器内部就可以用暴露的IP访问
 
 集群内部额外的还能使用service名.命名空间.svc:端口 
curl my-dep.default.svc:8000
 
但是此时，集群外，服务器无法直接用service名访问 
service的服务发现，下线pod 流量会自动转到其他service的pod不影响访问，再加入pod也会自动负载均衡 
1、ClusterIP 
# 等同于没有可以不加 --type 默认clusterIP，集群内访问
kubectl expose deployment my-dep --port=8000 --target-port=80 --type=ClusterIP
 
2、NodePort 
kubectl expose deployment my-dep --port=8000 --target-port=80 --type=NodePort
 
先删除之前的clusterip type，暴露为nodeport。随机分配一个端口31586 ，8000用作集群内访问，随机端口用作公网访问
  
Ingress 

 1、安装 
wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.47.0/deploy/static/provider/baremetal/deploy.yaml
#修改镜像
vi deploy.yaml

#将323行的镜像地址改为阿里云镜像地址
image: k8s.gcr.io/ingress-nginx/controller:v0.46.0@sha256:52f0058bed0a17ab0fb35628ba97e8d52b5d32299fbc03cc0f6c7b9ff036b61a
----改为
image: registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/ingress-nginx-controller:v0.46.0

# 检查安装的结果
kubectl get pod,svc -n ingress-nginx

# 最后别忘记把svc暴露的端口要放行
 
安装完成后 
# ingress的安装会产生一个service，ingress要承接所有的流量，
# 所以产生一个service对外暴露承接流量的端口
# 查看svc详细信息
kubectl get svc -A

ingress-nginx          ingress-nginx-controller             NodePort    10.96.189.29            80:31735/TCP,443:31607/TCP   88s

# 暴露了http访问的80和https访问的443端口，并随机映射到集群内nodeport端口
# nodeport的端口范围在
30000 - 32767
 
任意集群服务器的公网IP都能通过这两个端口访问到ingress 
Ingress的使用 
官网地址：https://kubernetes.github.io/ingress-nginx/
 就是nginx做的 
应用如下yaml，准备好测试环境 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-server
spec:
  replicas: 2
  selector:
    matchLabels:
      app: hello-server
  template:
    metadata:
      labels:
        app: hello-server
    spec:
      containers:
      - name: hello-server
        image: registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/hello-server
        ports:
        - containerPort: 9000
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx-demo
  name: nginx-demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-demo
  template:
    metadata:
      labels:
        app: nginx-demo
    spec:
      containers:
      - image: nginx
        name: nginx
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: nginx-demo
  name: nginx-demo
spec:
  selector:
    app: nginx-demo
  ports:
  - port: 8000
    protocol: TCP
    targetPort: 80
---
apiVersion: v1
kind: Service
metadata:
  labels:
    app: hello-server
  name: hello-server
spec:
  selector:
    app: hello-server
  ports:
  - port: 8000
    protocol: TCP
    targetPort: 9000
 
此yml文件的动作为，前两部分为：产生了两个deployment，每个部署了两个pod。
 后两部分，产生了两个service，service selector分别选中了之前两次部署的pod，新开端口port映射到pod的端口targetPort，做到负载均衡 
deployment ：部署的作用是做到pod的自愈
 service：作用是负载均衡 
添加Ingress的域名访问规则，相当于Spring cloud的GateWay了 
apiVersion: networking.k8s.io/v1
kind: Ingress  
metadata:
  name: ingress-host-bar
spec:
  ingressClassName: nginx
  rules:
  - host: "hello.atguigu.com"
    http:
      paths:
      - pathType: Prefix
        path: "/"
        backend:
          service:
            name: hello-server
            port:
              number: 8000
  - host: "demo.atguigu.com"
    http:
      paths:
      - pathType: Prefix
        path: "/nginx"  # 把请求会转给下面的服务，下面的服务一定要能处理这个路径，不能处理就是404
        backend:
          service:
            name: nginx-demo  ## java，比如使用路径重写，去掉前缀nginx
            port:
              number: 8000
 
修改本机host文件，因为集群内任意服务器的公网IP都能访问到集群
 
 此时通过 
# 查看Ingress的暴露端口来访问Ingress
kubectl get svc -A

http://hello.atguigu.com:31735/
http://demo.atguigu.com:31735/nginx
 
成功负载均衡的访问到 service下的pod 
Ingress的路径重写 
apiVersion: networking.k8s.io/v1
kind: Ingress  
metadata:
  annotations:   # 路径重写
    nginx.ingress.kubernetes.io/rewrite-target: /$2
  name: ingress-host-bar
spec:
  ingressClassName: nginx
  rules:
  - host: "hello.atguigu.com"
    http:
      paths:
      - pathType: Prefix
        path: "/"
        backend:
          service:
            name: hello-server
            port:
              number: 8000
  - host: "demo.atguigu.com"
    http:
      paths:
      - pathType: Prefix
        path: "/nginx(/|$)(.*)"  #(路径重写) 把请求会转给下面的服务，下面的服务一定要能处理这个路径，不能处理就是404
        backend:
          service:
            name: nginx-demo  ## java，比如使用路径重写，去掉前缀nginx
            port:
              number: 8000
 
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-limit-rate
  annotations:
    nginx.ingress.kubernetes.io/limit-rps: "1"
spec:
  ingressClassName: nginx
  rules:
  - host: "haha.atguigu.com"
    http:
      paths:
      - pathType: Exact
        path: "/"
        backend:
          service:
            name: nginx-demo
            port:
              number: 8000
 
Ingress网络模型总结 
 
存储抽象 
 
环境准备 
1、所有节点 
#所有机器安装
yum install -y nfs-utils
 
2、主节点 
#nfs主节点暴露/nfs/data/ 目录 *所有人。 非安全、读写
echo "/nfs/data/ *(insecure,rw,sync,no_root_squash)" > /etc/exports

# 主节点创建那个目录
mkdir -p /nfs/data
systemctl enable rpcbind --now
systemctl enable nfs-server --now
#配置生效
exportfs -r
 
3、从节点 
#  查看主节点挂载详情 主节点IP
showmount -e 172.31.0.2

#执行以下命令挂载 nfs 服务器上的共享目录到本机路径 /root/nfsmount
mkdir -p /nfs/data

mount -t nfs 172.31.0.2:/nfs/data /nfs/data
# 写入一个测试文件
echo "hello nfs server" > /nfs/data/test.txt
 
4、Deployment使用NFS挂载 
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx-pv-demo
  name: nginx-pv-demo
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-pv-demo
  template:
    metadata:
      labels:
        app: nginx-pv-demo
    spec:
      containers:
      - image: nginx
        name: nginx
        volumeMounts:
        - name: html
          mountPath: /usr/share/nginx/html
      volumes:
        - name: html
          nfs:
            server: 172.31.0.2
            path: /nfs/data/nginx-pv
 
创建时 
# 查看容器运行情况
kubectl get pod -A 

# 查看容器描述
kubectl describe NAME
 
发现容器创建错误，没有指定目录，我们删除本次deployment，重新部署。注意先创建挂载目录 
PV&PVC 
PV：持久卷（Persistent Volume），将应用需要持久化的数据保存到指定位置（场地）
 PVC：持久卷申明（Persistent Volume Claim），申明需要使用的持久卷规格（场地申明） 
PVC会自动合理的选择大小合适的PV 
1、创建pv池 
#nfs主节点
mkdir -p /nfs/data/01
mkdir -p /nfs/data/02
mkdir -p /nfs/data/03
 
创建PV 
文件分成了三块所以会申明三个pv， 
apiVersion: v1
kind: PersistentVolume # 资源类型，pv
metadata:
  name: pv01-10m #别名
spec:
  capacity:
    storage: 10M #限制容量大小
  accessModes:
    - ReadWriteMany #读写模式 可读、写、多节点
  storageClassName: nfs # class别名
  nfs:
    path: /nfs/data/01
    server: 172.31.0.2 # 当前节点地址 master
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv02-1gi
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/02
    server: 172.31.0.2
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv03-3gi
spec:
  capacity:
    storage: 3Gi
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/03
    server: 172.31.0.2
 
查看创建情况 
kubectl get persistentvolume(pv)
 
2、PVC创建与绑定
 创建pvc 
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: nginx-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 200Mi
  storageClassName: nfs
 
实际使用中还是pod不再绑定nfs而是绑定pvc
 创建Pod绑定PVC 
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx-deploy-pvc
  name: nginx-deploy-pvc
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-deploy-pvc
  template:
    metadata:
      labels:
        app: nginx-deploy-pvc
    spec:
      containers:
      - image: nginx
        name: nginx
        volumeMounts:
        - name: html
          mountPath: /usr/share/nginx/html
      volumes: # 这里指定pvc
        - name: html
          persistentVolumeClaim:
            claimName: nginx-pvc
 
# 修改挂载卷的内容后，进入容器查看内容是否一同变化
kubectl exec -ti nginx-deploy-pvc-79fc8558c7-hmhq2 /bin/bash

 
ConfigMap 
抽取应用配置，并且可以自动更新 
redis示例 
1、把预先创建好的配置文件设置为配置集 
# 创建配置，redis保存到k8s的etcd；
kubectl create cm redis-conf --from-file=redis.conf
 
kubectl get cm redis-conf -oyml
 获取到生成的配置文件内容 
apiVersion: v1
data:    #data是所有真正的数据，key：默认是文件名   value：配置文件的内容
  redis.conf: |
    appendonly yes
kind: ConfigMap
metadata:
  name: redis-conf
  namespace: default
 
2、创建Pod 
apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis
    image: redis
    command:
      - redis-server
      - "/redis-master/redis.conf"  #指的是redis容器内部的位置
    ports:
    - containerPort: 6379
    volumeMounts:
    - mountPath: /data
      name: data
    - mountPath: /redis-master
      name: config
  volumes:
    - name: data
      emptyDir: {}
    - name: config
      configMap:
        name: redis-conf
        items:
        - key: redis.conf
          path: redis.conf
 
 
3、检查默认配置 
kubectl exec -it redis -- redis-cli

127.0.0.1:6379> ConFIG GET appendonly
127.0.0.1:6379> ConFIG GET requirepass
 
4、修改ConfigMap 
kubectl edit cm redis-conf 
apiVersion: v1
kind: ConfigMap
metadata:
  name: example-redis-config
data:
  redis-config: |
    appendonly yes
    requirepass 123123
 
再次检查配置
 有些配置需要重启pod才会生效 
Secret 
Secret 对象类型用来保存敏感信息，例如密码、OAuth 令牌和 SSH 密钥。 将这些信息放在 secret 中比放在 Pod 的定义或者 容器镜像 中来说更加安全和灵活。 
kubectl create secret docker-registry leifengyang-docker 
--docker-username=leifengyang 
--docker-password=Lfy123456 
--docker-email=534096094@qq.com

##命令格式
kubectl create secret docker-registry regcred 
  --docker-server=<你的镜像仓库服务器> 
  --docker-username=<你的用户名> 
  --docker-password=<你的密码> 
  --docker-email=<你的邮箱地址>
 
apiVersion: v1
kind: Pod
metadata:
  name: private-nginx
spec:
  containers:
  - name: private-nginx
    image: leifengyang/guignginx:v1.0
  imagePullSecrets: # 指定存储好的secret
  - name: leifengyang-docker
 
end

云原生Java架构实战 K8s+Docker+KubeSphere+DevOps（上）

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