kubernetes(k8s)：包管理工具Helm

我就是我 2023-02-16 01:58 115阅读 0赞

### 文章目录 ###

*  1.Helm简介
 *  2. Helm的部署
 *  3. Helm 部署应用(拉取仓库的redis-ha并部署)
 *   *  案例：部署redis-ha，实现高可用

# 1.Helm简介 #

*  Helm是Kubernetes 应用的包管理工具，主要用来管理 Charts，类似Linux系统的yum。
 *  **Helm Chart** 是用来封装 Kubernetes 原生应用程序的一系列 YAML 文件。可以在你部署应用的时候自定义应用程序的一些Metadata，以便于应用程序的分发。
 *  对于应用发布者而言，可以通过 Helm 打包应用、管理应用依赖关系、管理应用版本并发布应用到软件仓库。
 *  对于使用者而言，使用 Helm 后不用需要编写复杂的应用部署文件，可以以简单的方式在 Kubernetes上查找、安装、升级、回滚、卸载应用程序。

Helm当前最新版本 v3.2.0 官网：[https://helm.sh/docs/intro/][https_helm.sh_docs_intro]  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ_size_16_color_FFFFFF_t_70]Helm V3 与 V2 最大的区别在于去掉了tiller，见下图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ_size_16_color_FFFFFF_t_70 1]本节使用的是 Helm V3

# 2. Helm的部署 #

Helm当前最新版本 v3.1.0 官网：[https://helm.sh/docs/intro/][https_helm.sh_docs_intro]

**Helm安装：**

下载软件包：helm-v3.1.1-linux-amd64.tar.gz
    [root@server1 ~]# tar zxf helm-v3.1.1-linux-amd64.tar.gz
    [root@server1 ~]# cd linux-amd64/
    [root@server1 linux-amd64]# ls
    helm  LICENSE  README.md
    [root@server1 ~]# cp helm /usr/local/bin/

设置helm命令补齐：

[kubeadm@server1 ~]$ echo "source <(helm completion bash)" >> ~/.bashrc

重新登陆生效

[root@server1 ~]# su - kubeadm
    Last login: Mon May 11 09:16:14 CST 2020 on pts/1
    Last failed login: Mon May 11 11:38:46 CST 2020 on pts/1
    There was 1 failed login attempt since the last successful login.
    [kubeadm@server1 ~]$ helm          //helm命令
    completion  dependency  get         install     list        plugin      repo        search      status      test        upgrade     version
    create      env         history     lint        package     pull        rollback    show        template    uninstall   verify

![在这里插入图片描述][2020060716223235.png]  
**Helm 添加第三方 Chart 库：**

[kubeadm@server1 ~]$ helm repo add stable http://mirror.azure.cn/kubernetes/charts/
    "stable" has been added to your repositories
    [kubeadm@server1 ~]$ helm repo list
    NAME  	URL                                      
    stable	http://mirror.azure.cn/kubernetes/charts/
    
    [kubeadm@server1 ~]$ helm search repo redis
    NAME                            	CHART VERSION	APP VERSION	DESCRIPTION                                       
    stable/prometheus-redis-exporter	3.4.0        	1.3.4      	Prometheus exporter for Redis metrics             
    stable/redis                    	10.5.7       	5.0.7      	DEPRECATED Open source, advanced key-value stor...
    stable/redis-ha                 	4.4.4        	5.0.6      	Highly available Kubernetes implementation of R...
    stable/sensu                    	0.2.3        	0.28       	Sensu monitoring framework backed by the Redis ...

# 3. Helm 部署应用(拉取仓库的redis-ha并部署) #

[kubeadm@server1 ~]$ helm search repo redis-ha -l  // 可以查看redis-ha的所有版本
    NAME           	CHART VERSION	APP VERSION	DESCRIPTION                                       
    stable/redis-ha	4.4.4        	5.0.6      	Highly available Kubernetes implementation of R...
    stable/redis-ha	4.4.3        	5.0.6      	Highly available Kubernetes implementation of R...
    stable/redis-ha	4.4.2        	5.0.6      	Highly available Kubernetes implementation of R...
    stable/redis-ha	4.4.1        	5.0.6      	Highly available Kubernetes implementation of R...
    stable/redis-ha	4.4.0        	5.0.6      	Highly available Kubernetes implementation of R...
    stable/redis-ha	4.3.4        	5.0.6      	Highly available Kubernetes implementation of R...

[kubeadm@server1 ~]$ helm pull stable/redis-ha // 拉取应用到本地，默认拉取最新版本
    
    [kubeadm@server1 ~]$ ls  // 拉取了一个redis-ha的压缩包
    components.yaml  dashrbac.yaml  kube-flannel.yml  manifest  recommended.yaml  redis-ha-4.4.4.tgz
    [kubeadm@server1 ~]$ mkdir helm
    [kubeadm@server1 ~]$ tar zxf redis-ha-4.4.4.tgz -C helm/  // 解压到helm目录

[kubeadm@server1 redis-ha]$ sudo yum install tree -y
    [kubeadm@server1 redis-ha]$ tree .  // 查看目录结构
    .
    ├── Chart.yaml
    ├── ci
    │   └── haproxy-enabled-values.yaml
    ├── OWNERS
    ├── README.md
    ├── templates
    │   ├── _configs.tpl
    │   ├── _helpers.tpl
    │   ├── NOTES.txt
    │   ├── redis-auth-secret.yaml
    │   ├── redis-ha-announce-service.yaml
    │   ├── redis-ha-configmap.yaml
    │   ├── redis-ha-exporter-script-configmap.yaml
    │   ├── redis-ha-pdb.yaml
    │   ├── redis-haproxy-deployment.yaml
    │   ├── redis-haproxy-serviceaccount.yaml
    │   ├── redis-haproxy-servicemonitor.yaml
    │   ├── redis-haproxy-service.yaml
    │   ├── redis-ha-rolebinding.yaml
    │   ├── redis-ha-role.yaml
    │   ├── redis-ha-serviceaccount.yaml
    │   ├── redis-ha-servicemonitor.yaml
    │   ├── redis-ha-service.yaml
    │   ├── redis-ha-statefulset.yaml
    │   └── tests
    │       ├── test-redis-ha-configmap.yaml
    │       └── test-redis-ha-pod.yaml
    └── values.yaml
    
    3 directories, 25 files

我们重点关注的是 `values.yaml`文件 进行修改和编辑

## 案例：部署redis-ha，实现高可用 ##

（1）将镜像拉取到本地harbor之后

需要redis:5.0.6-alpine的镜像
    [root@server1 harbor]# docker pull redis:5.0.6-alpine
    [root@server1 harbor]# docker tag redis:5.0.6-alpine reg.westos.org/library/redis:5.0.6-alpine
    [root@server1 harbor]# docker push reg.westos.org/library/redis

[kubeadm@server1 redis-ha]$ kubectl create namespace redis    //创建redis命名空间
    [kubeadm@server1 redis-ha]$ helm -n redis install redis    //在redisnamespace下安装redis
    NAME: redis-ha
    LAST DEPLOYED: Mon May 11 13:04:20 2020
    NAMESPACE: redis
    STATUS: deployed
    REVISION: 1
    NOTES:
    Redis can be accessed via port 6379 and Sentinel can be accessed via port 26379 on the following DNS name from within your cluster:
    redis-ha.redis.svc.cluster.local
    
    To connect to your Redis server:
    1. Run a Redis pod that you can use as a client:
    
       kubectl exec -it redis-ha-server-0 sh -n redis
    
    2. Connect using the Redis CLI:
    
      redis-cli -h redis-ha.redis.svc.cluster.local

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ_size_16_color_FFFFFF_t_70 2]（2）创建后查看：

[kubeadm@server1 redis-ha]$ kubectl -n redis get all  // redis-ha部署完成
    NAME                    READY   STATUS    RESTARTS   AGE
    pod/redis-ha-server-0   2/2     Running   0          2m16s
    pod/redis-ha-server-1   2/2     Running   0          107s
    pod/redis-ha-server-2   0/2     Pending   0          77s
    
    NAME                          TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)              AGE
    service/redis-ha              ClusterIP   None             <none>        6379/TCP,26379/TCP   2m19s
    service/redis-ha-announce-0   ClusterIP   10.100.4.107     <none>        6379/TCP,26379/TCP   2m18s
    service/redis-ha-announce-1   ClusterIP   10.109.211.70    <none>        6379/TCP,26379/TCP   2m18s
    service/redis-ha-announce-2   ClusterIP   10.105.156.107   <none>        6379/TCP,26379/TCP   2m18s
    
    NAME                               READY   AGE
    statefulset.apps/redis-ha-server   2/3     2m17s
    
    [kubeadm@server1 redis-ha]$ kubectl -n redis describe pod redis-ha-server-0  //pod中由两个容器redis和sentinel
    Containers:
      redis:
      sentinel: // 负责主从切换

可以看到创建了两个pod，其中server-0为master，还有两个svc和一个statefulset控制器。

（3）测试redis集群高可用

每个pod中有两个容器redis和sentinel，我们进入redis容器查看：

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ_size_16_color_FFFFFF_t_70 3]

[kubeadm@server1 redis-ha]$ kubectl -n redis exec -it redis-ha-server-0 -c redis -- sh  // 进入redis-ha-server-0，-c 指定进入的容器时redis
    /data $ redis-cli
    127.0.0.1:6379> info // 查看master的信息
    /data $ redis-cli -h 10.109.211.70  // 进入salve
    10.109.211.70:6379> info
    
    /data $ nslookup redis-ha.redis.svc.cluster.local
    nslookup: can't resolve '(null)': Name does not resolve
    
    Name:      redis-ha.redis.svc.cluster.local
    Address 1: 10.244.1.147 redis-ha-server-0.redis-ha.redis.svc.cluster.local
    Address 2: 10.244.2.131 redis-ha-server-1.redis-ha.redis.svc.cluster.local
    
    /data $ redis-cli -h redis-ha-server-1.redis-ha.redis.svc.cluster.local
    redis-ha-server-1.redis-ha.redis.svc.cluster.local:6379> info  // 1是slave
    # Replication
    role:slave
    
    /data $ redis-cli -h redis-ha-server-0.redis-ha.redis.svc.cluster.local
    redis-ha-server-0.redis-ha.redis.svc.cluster.local:6379> info // 0是master
    # Replication
    role:master
    
    helm -n redis upgrade redis-ha  // 更新
    helm status redis-ha  // 查看状态
    helm -n redis uninstall redis-ha  // 删除卸载
    kubectl delete namespaces redis // 删除namespace
    helm -n redis history redis-ha  // 查看历史

[root@server1 redis-ha]# kubectl -n redis exec -it redis-ha-server-0 -c redis -- sh
    /data $ redis-cli
    127.0.0.1:6379> info Replication
    # Replication
    role:master
    connected_slaves:1
    min_slaves_good_slaves:1
    slave0:ip=10.101.152.37,port=6379,state=online,offset=25236,lag=0
    master_replid:4baa1ff233604d357f9a5b2d6b100f90192d309c
    master_replid2:0000000000000000000000000000000000000000
    master_repl_offset:25236
    second_repl_offset:-1
    repl_backlog_active:1
    repl_backlog_size:1048576
    repl_backlog_first_byte_offset:1
    repl_backlog_histlen:25236

使用`info Replication`来查看主机信息，可以看出redis-ha-server-0为master主机。  
执行`SHUTDOWN`命令来使主机宕机：

127.0.0.1:6379> SHUTDOWN
    command terminated with exit code 137

宕机后控制器会马上帮我们启动一个pod

[root@server1 redis-ha]# kubectl get pod -n redis 
    NAME                READY   STATUS    RESTARTS   AGE
    redis-ha-server-0   2/2     Running   1          4m57s
    redis-ha-server-1   2/2     Running   0          4m48s

等重建好了之后再次查看pod角色

[root@server1 redis-ha]# kubectl -n redis exec -it redis-ha-server-0 -c redis -- sh
    /data $ redis-cli
    127.0.0.1:6379> info Replication
    # Replication
    role:slave            //宕机后重启切换为slave
    master_host:10.101.152.37
    master_port:6379
    ...

可以看出redis-ha-server-0已经变成了从机，而主机的ip为10.101.152.37，这时就实现了主从故障的切换。

**主从故障切换**依靠 `sentinel`容器完成。

（4）可以直接更改变量文件中的副本数量实现集群的动态拉伸  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ_size_16_color_FFFFFF_t_70 4]（5）使用upgrade选项更新集群

[root@server1 redis-ha]# helm -n redis upgrade redis-ha .

更新后查看pod可以看出已经变成了3个

[root@server1 redis-ha]# kubectl -n redis get pod
    NAME                READY   STATUS    RESTARTS   AGE
    redis-ha-server-0   2/2     Running   2          20m
    redis-ha-server-1   2/2     Running   0          20m
    redis-ha-server-2   0/2     Pending   0          12s

也可以使用以下命令查看更新历史以便回滚

[root@server1 redis-ha]# helm -n redis history 
    Error: "helm history" requires 1 argument
    
    Usage:  helm history RELEASE_NAME [flags]
    [root@server1 redis-ha]# helm -n redis history redis-ha 
    REVISION	UPDATED                 	STATUS    	CHART         	APP VERSION	DESCRIPTION     
    1       	Sun May 10 23:15:35 2020	superseded	redis-ha-4.4.4	5.0.6      	Install complete
    2       	Sun May 10 23:35:35 2020	deployed  	redis-ha-4.4.4	5.0.6      	Upgrade complete

[https_helm.sh_docs_intro]: https://helm.sh/docs/intro/
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[2020060716223235.png]: https://img-blog.csdnimg.cn/2020060716223235.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20200607162606575.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ==,size_16,color_FFFFFF,t_70
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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ_size_16_color_FFFFFF_t_70 4]: https://img-blog.csdnimg.cn/20200607163720309.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzkzNjk2OQ==,size_16,color_FFFFFF,t_70