Kubernetes(K8s 1.27.x) 快速上手+实践，无废话纯享版（视频笔记）-编程知识

视频源：1.03-k8s是什么？_哔哩哔哩_bilibili

1 基础知识

1.1 K8s 有用么？

K8s有没有用

K8s要不要学？

参考资料:
https://www.infoq.com/articles/devops-and-cloud-trends-2022/?itm_source=articles_about_InfoQ-trends-report&itm_medium=link&itm_campaign=InfoQ-trends-report

1.2 K8s 是什么？

1.3 k8s 部署方式

目前Kubernetes的两类部署样式

1.4 k8s 环境解析

网络环境解析

部署结构解析

2 环境部署

2.1 基础环境配置

主机名规划

序号	主机ip	主机名规划
1	10.0.0.12	kubernetes-master.sswang.com kubernetes-master
2	10.0.0.15	kubernetes-node1.sswang.com kubernetes-node1
3	10.0.0.16	kubernetes-node2.sswang.com kubernetes-node2
4	10.0.0.17	kubernetes-node3.sswang.com kubernetes-node3
5	10.0.0.20	kubernetes-register.sswang.com kubernetes-register

跨主机免密码认证

生成秘钥对
ssh-keygen -t rsa 跨主机免密码认证
ssh-copy-id root@远程主机ip地址

Swap环境配置(所有主机操作)

临时禁用
swapoff -a永久禁用
sed -i 's/.*swap.*/#&/' /etc/fstab 内核参数调整
cat >> /etc/sysctl.d/k8s.conf << EOF
vm.swappiness=0
EOF
sysctl -p /etc/sysctl.d/k8s.conf

网络参数调整(所有主机操作)

配置iptables参数，使得流经网桥的流量也经过iptables/netfilter防火墙
cat >> /etc/sysctl.d/k8s.conf << EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
net.ipv4.ip_forward = 1
EOF配置生效
modprobe br_netfilter
modprobe overlay
sysctl -p /etc/sysctl.d/k8s.conf

2.2 容器环境操作

注意：所有主机操作

部署docker软件源

定制软件源
yum install -y yum-utils device-mapper-persistent-data lvm2
yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

安装最新版docker
yum list docker-ce --showduplicates | sort -r
yum install -y docker-ce
systemctl enable docker
systemctl start docker

docker加速器配置

配置加速器文件
]# cat >> /etc/docker/daemon.json <<-EOF
{"registry-mirrors": ["http://74f21445.m.daocloud.io","https://registry.docker-cn.com","http://hub-mirror.c.163.com","https://docker.mirrors.ustc.edu.cn"], "insecure-registries": ["kubernetes-register.sswang.com"], "exec-opts": ["native.cgroupdriver=systemd"]
}
EOF重启docker服务
systemctl restart docker

2.3 cri环境操作

注意：所有主机操作

获取软件

下载软件
mkdir /data/softs && cd /data/softs
wget https://github.com/Mirantis/cri-dockerd/releases/download/v0.3.2/cri-dockerd-0.3.2.amd64.tgz解压软件
tar xf cri-dockerd-0.3.2.amd64.tgz
mv cri-dockerd/cri-dockerd /usr/local/bin/检查效果
cri-dockerd --version

定制配置

定制配置文件
cat > /etc/systemd/system/cri-dockerd.service<<-EOF
[Unit]
Description=CRI Interface for Docker Application Container Engine
Documentation=https://docs.mirantis.com
After=network-online.target firewalld.service docker.service
Wants=network-online.target
[Service]
Type=notify
ExecStart=/usr/local/bin/cri-dockerd --pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google_containers/pause:3.9--network-plugin=cni --cni-conf-dir=/etc/cni/net.d --cni-bin-dir=/opt/cni/bin --container-runtime-endpoint=unix:///var/run/cri-dockerd.sock --cri-dockerd-root-directory=/var/lib/dockershim --docker-endpoint=unix:///var/run/docker.sock --cri-dockerd-root-directory=/var/lib/docker
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
StartLimitBurst=3
StartLimitInterval=60s
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
TasksMax=infinity
Delegate=yes
KillMode=process
[Install]
WantedBy=multi-user.target
EOF

定制配置
cat > /etc/systemd/system/cri-dockerd.socket <<-EOF
[Unit]
Description=CRI Docker Socket for the API
PartOf=cri-docker.service[Socket]
ListenStream=/var/run/cri-dockerd.sock
SocketMode=0660
SocketUser=root
SocketGroup=docker[Install]
WantedBy=sockets.target
EOF

设置服务开机自启动
systemctl daemon-reload
systemctl enable cri-dockerd.service
systemctl restart cri-dockerd.service

2.4 harbor仓库操作

准备工作

安装docker环境
参考 上一节docker环境部署

安装docker-compose
yum install -y docker-compose

获取软件

下载软件
mkdir /data/{softs,server} -p && cd /data/softs
wget https://github.com/goharbor/harbor/releases/download/v2.5.0/harbor-offline-installer-v2.5.0.tgz解压软件
tar -zxvf harbor-offline-installer-v2.5.0.tgz -C  /data/server/
cd /data/server/harbor/加载镜像
docker load < harbor.v2.5.0.tar.gz
docker images备份配置
cp harbor.yml.tmpl harbor.yml

修改配置

修改配置
[root@kubernetes-register /data/server/harbor]# vim harbor.yml.tmpl# 修改主机名hostname: kubernetes-register.sswang.comhttp:port: 80#https:  注释ssl相关的部分#  port: 443#  certificate: /your/certificate/path#  private_key: /your/private/key/path# 修改harbor的登录密码harbor_admin_password: 123456# 设定harbor的数据存储目录data_volume: /data/server/harbor/data

配置harbor
./prepare启动harbor
./install.sh检查效果
docker-compose ps

定制服务启动文件

定制服务启动文件 /etc/systemd/system/harbor.service
[Unit]
Description=Harbor
After=docker.service systemd-networkd.service systemd-resolved.service
Requires=docker.service
Documentation=http://github.com/vmware/harbor[Service]
Type=simple
Restart=on-failure
RestartSec=5
#需要注意harbor的安装位置
ExecStart=/usr/bin/docker-compose --file /data/server/harbor/docker-compose.yml up
ExecStop=/usr/bin/docker-compose --file /data/server/harbor/docker-compose.yml down[Install]
WantedBy=multi-user.target

加载服务配置文件
systemctl daemon-reload
启动服务
systemctl start harbor
检查状态
systemctl status harbor
设置开机自启动
systemctl enable harbor

harbor仓库定制

浏览器访问域名，用户名: admin, 密码：123456
创建sswang用户专用的项目仓库，名称为 sswang，权限为公开的

harbor仓库测试

登录仓库
# docker login kubernetes-register.sswang.com -u sswang
Password:   # 输入登录密码 A12345678a下载镜像
docker pull busybox定制镜像标签
docker tag busybox kubernetes-register.sswang.com/sswang/busybox:v0.1推送镜像
docker push kubernetes-register.sswang.com/sswang/busybox:v0.1

2.5 k8s集群初始化

软件部署

定制阿里云的关于kubernetes的软件源
]# cat > /etc/yum.repos.d/kubernetes.repo << EOF
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=0
repo_gpgcheck=0
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF更新软件源
yum makecache fast

master环境软件部署
yum install kubeadm kubectl kubelet -ynode环境软件部署
yum install kubeadm kubectl kubelet -y

确认基本配置

检查镜像文件列表
kubeadm config images list获取镜像文件
images=$(kubeadm config images list --kubernetes-version=1.27.3 | awk -F "/" '{print $NF}')
for i in ${images}
dodocker pull registry.aliyuncs.com/google_containers/$idocker tag registry.aliyuncs.com/google_containers/$i kubernetes-register.sswang.com/google_containers/$idocker push kubernetes-register.sswang.com/google_containers/$idocker rmi registry.aliyuncs.com/google_containers/$i
done

master节点初始化

环境初始化命令
kubeadm init --kubernetes-version=1.27.3 \
--apiserver-advertise-address=10.0.0.12 \
--image-repository kubernetes-register.superopsmsb.com/google_containers \
--service-cidr=10.96.0.0/12 \
--pod-network-cidr=10.244.0.0/16 \
--ignore-preflight-errors=Swap \
--cri-socket=unix:///var/run/cri-dockerd.sock

node节点加入集群

复制join命令，加入到master集群
kubeadm join 10.0.0.12:6443 --token vudfvt.fwpohpbb7yw2qy49 \--discovery-token-ca-cert-hash sha256:1... ...48545 --cri-socket=unix:///var/run/cri-dockerd.sock

2.6 k8s环境收尾操作

权限操作

定制kubernetes的登录权限
mkdir -p $HOME/.kube
cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

命令补全

放到master主机的环境文件中
echo "source <(kubectl completion bash)" >> ~/.bashrc
echo "source <(kubeadm completion bash)" >> ~/.bashrc
source ~/.bashrc

网络环境

网络定制
mkdir /data/kubernetes/flannel -p
cd /data/kubernetes/flannel获取配置文件
wget https://raw.githubusercontent.com/flannel-io/flannel/master/Documentation/kube-flannel.yml定制镜像标签
for i in $(grep image kube-flannel.yml | grep -v '#' | awk -F '/' '{print $NF}')
dodocker pull flannel/$idocker tag flannel/$i kubernetes-register.superopsmsb.com/google_containers/$idocker push kubernetes-register.superopsmsb.com/google_containers/$idocker rmi flannel/$i
done备份配置文件
cp kube-flannel.yml{,.bak}

修改配置文件
sed -i '/ image:/s/docker.io\/flannel/kubernetes-register.sswang.com\/google_containers/' kube-flannel.yml应用配置文件
kubectl apply -f kube-flannel.yml检查效果
kubectl get node

3 应用部署

3.1 应用管理解读

3.2 应用部署实践

资源对象管理关系

资源对象管理实践

手工方式：
kubectl run pod名称 --image=image地址

资源清单方式:
apiVersion: v1
kind: Pod
metadata:labels:run: my-podname: my-pod
spec:containers:- image: kubernetes-register.sswang.com/sswang/nginxname: my-pod

deployment资源实践

nginx-proxy应用的配置清单文件
apiVersion: apps/v1
kind: Deployment
metadata:name: sswang-nginx-proxylabels:app: nginx
spec:replicas: 1selector:matchLabels:app: nginxtemplate:metadata:labels:app: nginxspec:containers:- name: nginximage: kubernetes-register.sswang.com/sswang/nginxports:- containerPort: 80

nginx-web 的资源清单文件
apiVersion: apps/v1
kind: Deployment
metadata:name: sswang-nginx-weblabels:app: nginx-web
spec:replicas: 1selector:matchLabels:app: nginx-webtemplate:metadata:labels:app: nginx-webspec:containers:- name: nginximage: kubernetes-register.sswang.com/sswang/nginx_web:v0.1ports:- containerPort: 80

tomcat-web 的资源清单文件
apiVersion: apps/v1
kind: Deployment
metadata:name: sswang-tomcat-weblabels:app: tomcat-web
spec:replicas: 1selector:matchLabels:app: tomcat-webtemplate:metadata:labels:app: tomcat-webspec:containers:- name: tomcatimage: kubernetes-register.sswang.com/sswang/tomcat_web:v0.1ports:- containerPort: 8080

3.3 应用管理实践

资源对象隔离

namespace资源对象实践
apiVersion: v1
kind: Namespace
metadata:name: my-ns
---
apiVersion: apps/v1
kind: Deployment
metadata:name: sswang-tomcat-webnamespace: my-nslabels:app: tomcat-web
spec:replicas: 1selector:matchLabels:app: tomcat-webtemplate:metadata:labels:app: tomcat-webspec:containers:- name: tomcatimage: kubernetes-register.sswang.com/sswang/tomcat_web:v0.1ports:- containerPort: 8080

资源对象的扩缩容

资源对象扩缩容
kubectl scale deployment 资源对象名称 --replicas=目标数量 deployment/mysql修改应用镜像版本
kubectl set image deployment 资源对象名称 容器名称=镜像名称

4 应用访问

4.1 service对象定位

4.2 Service 实践

手工创建Service

根据应用部署资源对象，创建SVC对象
kubectl expose deployment nginx --port=80 --type=NodePort

yaml方式创建Service

nginx-web的service资源清单文件
apiVersion: v1
kind: Service
metadata:name: sswang-nginx-weblabels:app: nginx-web
spec:type: NodePortselector:app: nginx-webports:- protocol: TCPname: httpport: 80targetPort: 80nodePort: 31080

tomcat-web的service资源清单文件
apiVersion: v1
kind: Service
metadata:name: sswang-tomcat-weblabels:app: tomcat-web
spec:type: NodePortselector:app: tomcatports:- protocol: TCPname: httpport: 8080targetPort: 8080nodePort: 31880

4.3 外部Service

部署外部mysql环境

准备软件源
]# cat /etc/yum.repos.d/MariaDB.repo
[mariadb]
name = MariaDB
baseurl = http://yum.mariadb.org/10.3/centos7-amd64
gpgcheck=0更新系统软件包：
yum makecache fast安装 MySQL 服务器
yum install mariadb-server mariadb -y 设置 MySQL 服务在启动时自动启动
systemctl start mariadb.service
systemctl enable mariadb.service

开启 MySQL 服务器远程访问能力
]# vim /etc/my.cnf.d/server.cnf
[mysqld]
bind-address = 0.0.0.0重启 MySQL 服务使配置生效
systemctl restart mariadb.service配置远程主机登录权限
mysql -uroot -p123456 -e "GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;"
mysql -uroot -p123456 -e "FLUSH PRIVILEGES;"

主库上创建数据库
]# mysql -uroot -p123456 -e "
CREATE DATABASE bookinfo default charset utf8 collate utf8_general_ci;
USE bookinfo;
CREATE TABLE book_info (id INT AUTO_INCREMENT PRIMARY KEY,book_name VARCHAR(100),author VARCHAR(100),date_of_issue DATE,isDelete BOOLEAN
);
INSERT INTO book_info (book_name, author, date_of_issue, isDelete) VALUES('Book 1', 'Author 1', '2022-01-01', FALSE),('Book 2', 'Author 2', '2022-02-01', FALSE),('Book 3', 'Author 3', '2022-03-01', TRUE);
"

定制资源清单文件

apiVersion: v1
kind: Namespace
metadata:name: external-ns
---
apiVersion: v1
kind: Endpoints
metadata:name: ex-mysqlnamespace: external-ns
subsets:- addresses:- ip: 10.0.0.18ports:- port: 3306
---
apiVersion: v1
kind: Service
metadata:name: ex-mysqlnamespace: external-ns
spec:type: ClusterIPports:- port: 3306targetPort: 3306
---
apiVersion: apps/v1
kind: Deployment
metadata:name: bookinfonamespace: external-ns
spec:replicas: 1selector:matchLabels:app: flask-bookinfotemplate:metadata:labels:app: flask-bookinfospec:containers:- name: flask-bookinfoimage: kubernetes-register.sswang.com/sswang/flask_bookinfo:2.3.2imagePullPolicy: Alwaysports:- containerPort: 5000env:- name: DB_HOSTvalue: "ex-mysql"- name: DB_USERvalue: "root"- name: DB_PASSWORDvalue: "123456"- name: DB_DATABASEvalue: "bookinfo"

5 应用数据

5.1 应用数据解析

k8s应用数据类型和步骤解析

k8s如何使用数据功能

k8s使用各种数据类型的配置

5.2 应用数据实践

emptyDir实践

资源对象文件内容
apiVersion: v1
kind: Pod
metadata:name: sswang-emptydir
spec:containers:- name: nginx-webimage: kubernetes-register.sswang.com/sswang/nginx_web:v0.1volumeMounts:- name: nginx-indexmountPath: /usr/share/nginx/html- name: change-indeximage: kubernetes-register.sswang.com/sswang/busybox:1.28# 每过2秒更改一下文件内容command: ['sh', '-c', 'for i in $(seq 100); do echo index-$i > /testdir/index.html;sleep 2;done']volumeMounts:- name: nginx-indexmountPath: /testdirvolumes:- name: nginx-indexemptyDir: {}

hostPath实践

资源对象文件内容
apiVersion: v1
kind: Pod
metadata:name: sswang-hostpath
spec:volumes:- name: redis-backuphostPath:path: /data/backup/rediscontainers:- name: hostpath-redisimage: kubernetes-register.sswang.com/sswang/redis:7.0.4volumeMounts:- name: redis-backupmountPath: /data

6 应用配置

6.1 应用配置解析

k8s如何使用配置数据功能

6.2 配置文件实践

定制配置文件实践

定制资源清单文件
apiVersion: v1
kind: ConfigMap
metadata:name: sswang-nginxconf
data:default.conf: |server {listen 80;server_name www.sswang.com;location /nginx {proxy_pass http://sswang-nginx-web/;}location /tomcat {proxy_pass http://sswang-tomcat-web:8080/;}location / {root /usr/share/nginx/html;}}
---
apiVersion: v1
kind: ConfigMap
metadata:name: sswang-nginx-index
data:index.html: "Hello Nginx, This is Nginx Web Page by sswang!!!\n"

定制nginx-proxy代理
apiVersion: apps/v1
kind: Deployment
metadata:name: sswang-nginx-proxylabels:app: nginx
spec:replicas: 1selector:matchLabels:app: nginxtemplate:metadata:labels:app: nginxspec:containers:- name: nginximage: kubernetes-register.sswang.com/sswang/nginx_proxy:v0.1volumeMounts:- name: nginxconfmountPath: /etc/nginx/conf.d/readOnly: true- name: nginxindexmountPath: /usr/share/nginx/html/readOnly: truevolumes:- name: nginxconfconfigMap:name: sswang-nginxconf- name: nginxindexconfigMap:name: sswang-nginx-index
---
apiVersion: v1
kind: Service
metadata:name: superopsmsb-nginx-proxylabels:app: superopsmsb-nginx-proxy
spec:selector:app: nginxports:- protocol: TCPname: httpport: 80targetPort: 80

6.3 敏感文件实践

定制配置文件

准备nginx容器的配置目录
mkdir tls-key做证书
openssl  genrsa -out tls-key/tls.key 2048做成自签证书
openssl req  -new -x509 -key tls-key/tls.key  -out tls-key/tls.crt -subj "/CN=www.sswang.com"

定制专属nginx配置文件  nginx-conf-tls/default.conf
server {listen 443 ssl;server_name www.sswang.com;ssl_certificate /etc/nginx/certs/tls.crt; ssl_certificate_key /etc/nginx/certs/tls.key;location / {root /usr/share/nginx/html;}
}server {listen 80;server_name www.sswang.com; return 301 https://$host$request_uri; 
}

手工创建资源对象文件

创建cm资源对象
kubectl create configmap nginx-ssl-conf --from-file=nginx-conf-tls/创建secret资源对象
kubectl create secret tls nginx-ssl-secret --cert=tls-key/tls.crt --key=tls-key/tls.key

定制资源清单文件
apiVersion: v1
kind: Pod
metadata:name: sswang-nginx-ssl
spec:containers:- image: kubernetes-register.sswang.com/sswang/nginx_web:v0.1name: nginx-webvolumeMounts:- name: nginxcertsmountPath: /etc/nginx/certs/readOnly: true- name: nginxconfsmountPath: /etc/nginx/conf.d/readOnly: truevolumes:- name: nginxcertssecret:secretName: nginx-ssl-secret- name: nginxconfsconfigMap:name: nginx-ssl-conf

7 服务访问

7.1 Ingress简介

原理解析

Ingress是授权入站连接到达集群服务的规则集合。从外部流量调度到nodeport上的service从service调度到ingress-controlleringress-controller根据ingress[Pod]中的定义（虚拟主机或者后端的url）根据虚拟主机名直接调度到后端的一组应用pod中

7.2 Ingress部署

环境部署

获取配置文件
cd /data/kubernetes/app_secure
mkdir ingress ; cd ingress
wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.3.1/deploy/static/provider/baremetal/deploy.yaml
mv deploy.yaml ingress-deploy.yaml
cp ingress-deploy.yaml{,.bak}

默认镜像
]# grep image: ingress-deploy.yaml | awk -F '/|@' '{print $(NF-1)}' | uniq
controller:v1.3.1
kube-webhook-certgen:v1.3.0获取镜像
for i in nginx-ingress-controller:v1.3.1 kube-webhook-certgen:v1.3.0
dodocker pull registry.cn-hangzhou.aliyuncs.com/google_containers/$idocker tag registry.cn-hangzhou.aliyuncs.com/google_containers/$i kubernetes-register.sswang.com/google_containers/$idocker push kubernetes-register.sswang.com/google_containers/$idocker rmi registry.cn-hangzhou.aliyuncs.com/google_containers/$i
done
注意：controller的名称是需要更改一下，阿里云的镜像名称多了一个标识

修改基础镜像
]# grep image: ingress-deploy.yamlimage: kubernetes-register.sswang.com/google_containers/nginx-ingress-controller:v1.3.1image: kubernetes-register.sswang.com/google_containers/kube-webhook-certgen:v1.3.0image: kubernetes-register.sswang.com/google_containers/kube-webhook-certgen:v1.3.0开放访问入口地址  
]# vim ingress-deploy.yaml
...
334 apiVersion: v1
335 kind: Service
...
344   namespace: ingress-nginx
345 spec:...
348   ipFamilyPolicy: SingleStack
349   externalIPs: ['10.0.0.12']			# 限制集群外部访问的入口ip
350   ports:
351   - appProtocol: http
352     name: http
353     port: 80
...
628   failurePolicy: Ignore				    # 为了避免默认的准入控制限制，改为Ignore
...

应用资源配置文件
]# kubectl apply -f ingress-deploy.yaml确认效果
]# kubectl get all -n ingress-nginx
NAME                                            READY   STATUS      RESTARTS   AGE
pod/ingress-nginx-admission-create-s5p7h        0/1     Completed   0          105s
pod/ingress-nginx-admission-patch-qnjmv         0/1     Completed   0          105s
pod/ingress-nginx-controller-6cc467dfd9-c2dfg   1/1     Running     0          105sNAME                                         TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
service/ingress-nginx-controller             NodePort    10.109.163.145   10.0.0.12     80:30439/TCP,443:31912/TCP   105s
service/ingress-nginx-controller-admission   ClusterIP   10.96.223.121    <none>        443/TCP                      105sNAME                                       READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/ingress-nginx-controller   1/1     1            1           105sNAME                                                  DESIRED   CURRENT   READY   AGE
replicaset.apps/ingress-nginx-controller-6cc467dfd9   1         1         1       105sNAME                                       COMPLETIONS   DURATION   AGE
job.batch/ingress-nginx-admission-create   1/1           8s         105s
job.batch/ingress-nginx-admission-patch    1/1           7s         105s

测试访问页面
]# curl 10.0.0.12:30439
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx</center>
</body>
</html>

7.3 Ingress实践

定制资源清单文件

定制资源清单文件
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:name: superopsmsb-ingress-mulhostannotations:kubernetes.io/ingress.class: "nginx"
spec:rules:- host: nginx.sswang.comhttp:paths:- path: /pathType: Prefixbackend:service:name: sswang-nginx-webport:number: 80- host: tomcat.sswang.comhttp:paths:- path: /pathType: Prefixbackend:service:name: sswang-tomcat-webport:number: 8080

8 helm管理

8.1 helm简介

需求

在kubernetes平台上，我们在部署各种各样的应用服务的时候，可以基于手工或者自动的方式对各种资源对象实现伸缩操作，尤其是对于有状态的应用，我们可以结合持久性存储机制实现更大场景的伸缩动作。但是，无论我们怎么操作各种资源对象，问题最多的就是各种基础配置、镜像等之类的依赖管理操作。在linux平台下，常见的包依赖的就是yum、apt等工具，在kubernetes平台下，同样有类似的解决依赖关系的工具 -- helm。

官方网址：https://v3.helm.sh/
官方地址：https://github.com/helm/helm

简介

helm的功能类似于yum 或 apt，提供应用部署时候所需要的各种配置、资源清单文件，他与yum之类工具不同的是，在k8s中helm是不提供镜像的，这些镜像文件需要由专门的镜像仓库来提供。例如：k8s平台上的nginx应用部署，对于该应用部署来说，主要需要三类内容：镜像：nginx镜像资源定义文件：Deployment、service、hpa等专用文件：配置文件、证书等helm管理的主要是：资源定义文件和专用文件。

基于helm来成功的部署一个应用服务，完整的工作流程如下：
1 部署一个稳定运行的k8s集群，在能管理k8s的主机上部署helm。
2 用户在客户端主机上，定制各种Chart资源和config资源，上传到专用的仓库(本地或者远程)
3 helm客户端向Tiller发出部署请求，如果本地有chart用本地的，否则从仓库获取
4 Tiller与k8s集群的api-server发送请求
5 api-server通过集群内部机制部署应用，需要依赖镜像的时候，从专门的镜像仓库获取。
6 基于helm部署好的应用实例，在k8s集群中，我们称之为release。

v3介绍

根据我们对 helm v2 版本的流程解析，我们发现，在客户端上部署tiller来维护 release相关的信息，有些太重量级了，所以在 helm v3 版本的时候，就剔除了专门的Tiller。在 Helm v3 中移除了 Tiller, 版本相关的数据直接存储在了 Kubernetes 中.

8.2 helm部署

软件部署

下载软件
cd /data/softs
wget https://get.helm.sh/helm-v3.13.0-linux-amd64.tar.gz配置环境
mkdir /data/server/helm/bin -p
tar xf helm-v3.13.0-linux-amd64.tar.gz
mv linux-amd64/helm /data/server/helm/bin/环境变量
# cat /etc/profile.d/helm.sh
#!/bin/bash
# set helm env
export PATH=$PATH:/data/server/helm/binchmod +x /etc/profile.d/helm.sh
source /etc/profile.d/helm.sh确认效果
# helm  version
version.BuildInfo{Version:"v3.13.0", GitCommit:"1d11fcb5d3f3bf00dbe6fe31b8412839a96b3dc4", GitTreeState:"clean", GoVersion:"go1.16.9"}

命令帮助

# helm --help
The Kubernetes package managerCommon actions for Helm:- helm search:    search for charts
- helm pull:      download a chart to your local directory to view
- helm install:   upload the chart to Kubernetes
- helm list:      list releases of charts

8.3 helm实践

仓库管理

添加仓库 
helm repo add az-stable http://mirror.azure.cn/kubernetes/charts/
helm repo add bitnami https://charts.bitnami.com/bitnami查看仓库
# helm repo list
NAME            URL
az-stable       http://mirror.azure.cn/kubernetes/charts/
bitnami         https://charts.bitnami.com/bitnami更新仓库属性信息
helm repo update

搜索chart信息
# helm search --help
...
Available Commands:hub         search for charts in the Artifact Hub or your own hub instancerepo        search repositories for a keyword in charts结果显示：helm 有两种搜索的源地址，官方的在 Artifact，幸运的是，无法访问。从自定义仓库中获取源信息
helm search repo redis

查看chart的所有信息
helm show all bitnami/redis

redis实践

安装chart
helm install my_helm bitnami/redis删除应用
helm uninstall my-helm更新应用
helm install my-helm bitnami/redis --set master.persistence.enabled=false --set replica.persistence.enabled=false查看效果
helm list
kubectl get pod

简单实践

查看基本操作的信息
helm status my-helm获取具备读写权限的主机域名redis主角色主机： my-helm-redis-master.default.svc.cluster.localredis从角色主机： my-helm-redis-replicas.default.svc.cluster.local获取连接密码
# export REDIS_PASSWORD=$(kubectl get secret --namespace default my-helm-redis -o jsonpath="{.data.redis-password}" | base64 --decode)
# echo $REDIS_PASSWORD
ID6KzPAZc1创建客户端
# kubectl run --namespace default redis-client --restart='Never'  --env REDIS_PASSWORD=$REDIS_PASSWORD  --image docker.io/bitnami/redis:6.2.6-debian-10-r0 --command -- sleep infinity连接redis主角色
$ redis-cli -h my-helm-redis-master.default.svc.cluster.local -a ID6KzPAZc1redis操作
my-helm-redis-master.default.svc.cluster.local:6379> set a 1
OK
my-helm-redis-master.default.svc.cluster.local:6379> set b 2
OK
my-helm-redis-master.default.svc.cluster.local:6379> keys *
1) "a"
2) "b"
my-helm-redis-master.default.svc.cluster.local:6379> get a
"1"