Kubernetes K8S之Helm部署、使用、常见操作与示例
服务器名称(hostname) | 系统版本 | 配置 | 内网IP | 外网IP(模拟) |
---|---|---|---|---|
k8s-master | CentOS7.7 | 2C/4G/20G | 172.16.1.110 | 10.0.0.110 |
k8s-node01 | CentOS7.7 | 2C/4G/20G | 172.16.1.111 | 10.0.0.111 |
k8s-node02 | CentOS7.7 | 2C/4G/20G | 172.16.1.112 | 10.0.0.112 |
没有使用Helm之前,在Kubernetes部署应用,我们要依次部署deployment、service等,步骤比较繁琐。况且随着很多项目微服务化,复杂的应用在容器中部署以及管理显得较为复杂。
helm通过打包的方式,支持发布的版本管理和控制,很大程度上简化了Kubernetes应用的部署和管理。
Helm本质就是让k8s的应用管理(Deployment、Service等)可配置,能动态生成。通过动态生成K8S资源清单文件(deployment.yaml、service.yaml)。然后kubectl自动调用K8S资源部署。
Helm是官方提供类似于YUM的包管理,是部署环境的流程封装,Helm有三个重要的概念:chart、release和Repository
Helm包含两个组件:Helm客户端和Tiller服务端,如下图所示:
Helm 客户端负责 chart 和 release 的创建和管理以及和 Tiller 的交互。Tiller 服务端运行在 Kubernetes 集群中,它会处理Helm客户端的请求,与 Kubernetes API Server 交互。
现在越来越多的公司和团队开始使用Helm这个Kubernetes的包管理器,我们也会使用Helm安装Kubernetes的常用组件。Helm由客户端命令helm工具和服务端tiller组成。
helm的GitHub地址
https://github.com/helm/helm
本次部署版本
Helm安装部署
1 [root@k8s-master software]# pwd
2 /root/software
3 [root@k8s-master software]# wget https://get.helm.sh/helm-v2.16.9-linux-amd64.tar.gz
4 [root@k8s-master software]#
5 [root@k8s-master software]# tar xf helm-v2.16.9-linux-amd64.tar.gz
6 [root@k8s-master software]# ll
7 total 12624
8 -rw-r--r-- 1 root root 12926032 Jun 16 06:55 helm-v3.2.4-linux-amd64.tar.gz
9 drwxr-xr-x 2 3434 3434 50 Jun 16 06:55 linux-amd64
10 [root@k8s-master software]#
11 [root@k8s-master software]# cp -a linux-amd64/helm /usr/bin/helm
因为Kubernetes API Server开启了RBAC访问控制,所以需要创建tiller的service account:tiller并分配合适的角色给它。这里为了简单起见我们直接分配cluster-admin这个集群内置的ClusterRole给它。
1 [root@k8s-master helm]# pwd
2 /root/k8s_practice/helm
3 [root@k8s-master helm]#
4 [root@k8s-master helm]# cat rbac-helm.yaml
5 apiVersion: v1
6 kind: ServiceAccount
7 metadata:
8 name: tiller
9 namespace: kube-system
10 ---
11 apiVersion: rbac.authorization.k8s.io/v1
12 kind: ClusterRoleBinding
13 metadata:
14 name: tiller
15 roleRef:
16 apiGroup: rbac.authorization.k8s.io
17 kind: ClusterRole
18 name: cluster-admin
19 subjects:
20 - kind: ServiceAccount
21 name: tiller
22 namespace: kube-system
23 [root@k8s-master helm]#
24 [root@k8s-master helm]# kubectl apply -f rbac-helm.yaml
25 serviceaccount/tiller created
26 clusterrolebinding.rbac.authorization.k8s.io/tiller created
初始化Helm的client 和 server
1 [root@k8s-master helm]# helm init --service-account tiller
2 ………………
3 [root@k8s-master helm]# kubectl get pod -n kube-system -o wide | grep 'tiller'
4 tiller-deploy-8488d98b4c-j8txs 0/1 Pending 0 38m <none> <none> <none> <none>
5 [root@k8s-master helm]#
6 ##### 之所有没有调度成功,就是因为拉取镜像包失败;查看需要拉取的镜像包
7 [root@k8s-master helm]# kubectl describe pod tiller-deploy-8488d98b4c-j8txs -n kube-system
8 Name: tiller-deploy-8488d98b4c-j8txs
9 Namespace: kube-system
10 Priority: 0
11 Node: <none>
12 Labels: app=helm
13 name=tiller
14 pod-template-hash=8488d98b4c
15 Annotations: <none>
16 Status: Pending
17 IP:
18 IPs: <none>
19 Controlled By: ReplicaSet/tiller-deploy-8488d98b4c
20 Containers:
21 tiller:
22 Image: gcr.io/kubernetes-helm/tiller:v2.16.9
23 Ports: 44134/TCP, 44135/TCP
24 Host Ports: 0/TCP, 0/TCP
25 Liveness: http-get http://:44135/liveness delay=1s timeout=1s period=10s #success=1 #failure=3
26 Readiness: http-get http://:44135/readiness delay=1s timeout=1s period=10s #success=1 #failure=3
27 Environment:
28 TILLER_NAMESPACE: kube-system
29 TILLER_HISTORY_MAX: 0
30 Mounts:
31 /var/run/secrets/kubernetes.io/serviceaccount from tiller-token-kjqb7 (ro)
32 Conditions:
33 ………………
由上可见,镜像下载失败。原因是镜像在国外,因此这里需要修改镜像地址
1 [root@k8s-master helm]# helm init --upgrade --tiller-image registry.cn-beijing.aliyuncs.com/google_registry/tiller:v2.16.9
2 [root@k8s-master helm]#
3 ### 等待一会儿后
4 [root@k8s-master helm]# kubectl get pod -o wide -A | grep 'till'
5 kube-system tiller-deploy-7b7787d77-zln6t 1/1 Running 0 8m43s 10.244.4.123 k8s-node01 <none> <none>
由上可见,Helm服务端tiller部署成功
helm版本信息查看
1 [root@k8s-master helm]# helm version
2 Client: &version.Version{SemVer:"v2.16.9", GitCommit:"8ad7037828e5a0fca1009dabe290130da6368e39", GitTreeState:"clean"}
3 Server: &version.Version{SemVer:"v2.16.9", GitCommit:"8ad7037828e5a0fca1009dabe290130da6368e39", GitTreeState:"dirty"}
helm默认使用的charts源地址
1 [root@k8s-master helm]# helm repo list
2 NAME URL
3 stable https://kubernetes-charts.storage.googleapis.com
4 local http://127.0.0.1:8879/charts
改变helm源【是否改变helm源,根据实际情况而定,一般不需要修改】
1 helm repo remove stable
2 helm repo add stable https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts
3 helm repo update
4 helm repo list
helm安装包下载存放位置
/root/.helm/cache/archive
1 # 列出charts仓库中所有可用的应用
2 helm search
3 # 查询指定应用
4 helm search memcached
5 # 查询指定应用的具体信息
6 helm inspect stable/memcached
7 # 用helm安装软件包,--name:指定release名字
8 helm install --name memcached1 stable/memcached
9 # 查看安装的软件包
10 helm list
11 # 删除指定引用
12 helm delete memcached1
chart管理
1 create:根据给定的name创建一个新chart
2 fetch:从仓库下载chart,并(可选项)将其解压缩到本地目录中
3 inspect:chart详情
4 package:打包chart目录到一个chart归档
5 lint:语法检测
6 verify:验证位于给定路径的chart已被签名且有效
release管理
1 get:下载一个release
2 delete:根据给定的release name,从Kubernetes中删除指定的release
3 install:安装一个chart
4 list:显示release列表
5 upgrade:升级release
6 rollback:回滚release到之前的一个版本
7 status:显示release状态信息
8 history:Fetch release历史信息
1 # 添加仓库
2 helm repo add REPO_INFO # 如:helm repo add incubator http://storage.googleapis.com/kubernetes-charts-incubator
3 ##### 示例
4 helm repo add incubator http://storage.googleapis.com/kubernetes-charts-incubator
5 helm repo add elastic https://helm.elastic.co
6 # 查看helm仓库列表
7 helm repo list
8 # 创建chart【可供参考,一般都是自己手动创建chart】
9 helm create CHART_PATH
10 # 根据指定chart部署一个release
11 helm install --name RELEASE_NAME CHART_PATH
12 # 根据指定chart模拟安装一个release,并打印处debug信息
13 helm install --dry-run --debug --name RELEASE_NAME CHART_PATH
14 # 列出已经部署的release
15 helm list
16 # 列出所有的release
17 helm list --all
18 # 查询指定release的状态
19 helm status Release_NAME
20 # 回滚到指定版本的release,这里指定的helm release版本
21 helm rollback Release_NAME REVISION_NUM
22 # 查看指定release的历史信息
23 helm history Release_NAME
24 # 对指定chart打包
25 helm package CHART_PATH 如:helm package my-test-app/
26 # 对指定chart进行语法检测
27 helm lint CHART_PATH
28 # 查看指定chart详情
29 helm inspect CHART_PATH
30 # 从Kubernetes中删除指定release相关的资源【helm list --all 中仍然可见release记录信息】
31 helm delete RELEASE_NAME
32 # 从Kubernetes中删除指定release相关的资源,并删除release记录
33 helm delete --purge RELEASE_NAME
上述操作可结合下文示例,这样能看到更多细节。
1 [root@k8s-master helm]# pwd
2 /root/k8s_practice/helm
3 [root@k8s-master helm]#
4 [root@k8s-master helm]# mkdir my-test-app
5 [root@k8s-master helm]# cd my-test-app
6 [root@k8s-master my-test-app]#
7 [root@k8s-master my-test-app]# ll
8 total 8
9 -rw-r--r-- 1 root root 158 Jul 16 17:53 Chart.yaml
10 drwxr-xr-x 2 root root 49 Jul 16 21:04 templates
11 -rw-r--r-- 1 root root 129 Jul 16 21:04 values.yaml
12 [root@k8s-master my-test-app]#
13 [root@k8s-master my-test-app]# cat Chart.yaml
14 apiVersion: v1
15 appVersion: v2.2
16 description: my test app
17 keywords:
18 - myapp
19 maintainers:
20 - email: zhang@test.com
21 name: zhang
22 # 该name值与上级目录名相同
23 name: my-test-app
24 version: v1.0.0
25 [root@k8s-master my-test-app]#
26 [root@k8s-master my-test-app]# cat values.yaml
27 deployname: my-test-app02
28 replicaCount: 2
29 images:
30 repository: registry.cn-beijing.aliyuncs.com/google_registry/myapp
31 tag: v2
32 [root@k8s-master my-test-app]#
33 [root@k8s-master my-test-app]# ll templates/
34 total 8
35 -rw-r--r-- 1 root root 544 Jul 16 21:04 deployment.yaml
36 -rw-r--r-- 1 root root 222 Jul 16 20:41 service.yaml
37 [root@k8s-master my-test-app]#
38 [root@k8s-master my-test-app]# cat templates/deployment.yaml
39 apiVersion: apps/v1
40 kind: Deployment
41 metadata:
42 name: {{ .Values.deployname }}
43 labels:
44 app: mytestapp-deploy
45 spec:
46 replicas: {{ .Values.replicaCount }}
47 selector:
48 matchLabels:
49 app: mytestapp
50 env: test
51 template:
52 metadata:
53 labels:
54 app: mytestapp
55 env: test
56 description: mytest
57 spec:
58 containers:
59 - name: myapp-pod
60 image: {{ .Values.images.repository }}:{{ .Values.images.tag }}
61 imagePullPolicy: IfNotPresent
62 ports:
63 - containerPort: 80
64
65 [root@k8s-master my-test-app]#
66 [root@k8s-master my-test-app]# cat templates/service.yaml
67 apiVersion: v1
68 kind: Service
69 metadata:
70 name: my-test-app
71 namespace: default
72 spec:
73 type: NodePort
74 selector:
75 app: mytestapp
76 env: test
77 ports:
78 - name: http
79 port: 80
80 targetPort: 80
81 protocol: TCP
1 [root@k8s-master my-test-app]# pwd
2 /root/k8s_practice/helm/my-test-app
3 [root@k8s-master my-test-app]# ll
4 total 8
5 -rw-r--r-- 1 root root 160 Jul 16 21:15 Chart.yaml
6 drwxr-xr-x 2 root root 49 Jul 16 21:04 templates
7 -rw-r--r-- 1 root root 129 Jul 16 21:04 values.yaml
8 [root@k8s-master my-test-app]#
9 [root@k8s-master my-test-app]# helm install --name mytest-app01 . ### 如果在上级目录则为 helm install --name mytest-app01 my-test-app/
10 NAME: mytest-app01
11 LAST DEPLOYED: Thu Jul 16 21:18:08 2020
12 NAMESPACE: default
13 STATUS: DEPLOYED
14
15 RESOURCES:
16 ==> v1/Deployment
17 NAME READY UP-TO-DATE AVAILABLE AGE
18 my-test-app02 0/2 2 0 0s
19
20 ==> v1/Pod(related)
21 NAME READY STATUS RESTARTS AGE
22 my-test-app02-58cb6b67fc-4ss4v 0/1 ContainerCreating 0 0s
23 my-test-app02-58cb6b67fc-w2nhc 0/1 ContainerCreating 0 0s
24
25 ==> v1/Service
26 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
27 my-test-app NodePort 10.110.82.62 <none> 80:30965/TCP 0s
28
29 [root@k8s-master my-test-app]# helm list
30 NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
31 mytest-app01 1 Thu Jul 16 21:18:08 2020 DEPLOYED my-test-app-v1.0.0 v2.2 default
1 [root@k8s-master ~]# kubectl get pod -o wide
2 NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
3 my-test-app02-58cb6b67fc-4ss4v 1/1 Running 0 9m3s 10.244.2.187 k8s-node02 <none> <none>
4 my-test-app02-58cb6b67fc-w2nhc 1/1 Running 0 9m3s 10.244.4.134 k8s-node01 <none> <none>
5 [root@k8s-master ~]#
6 [root@k8s-master ~]# kubectl get svc -o wide
7 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
8 kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 65d <none>
9 my-test-app NodePort 10.110.82.62 <none> 80:30965/TCP 9m8s app=mytestapp,env=test
10 [root@k8s-master ~]#
11 ##### 根据svc的IP访问
12 [root@k8s-master ~]# curl 10.110.82.62
13 Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
14 [root@k8s-master ~]#
15 [root@k8s-master ~]# curl 10.110.82.62/hostname.html
16 my-test-app02-58cb6b67fc-4ss4v
17 [root@k8s-master ~]#
18 [root@k8s-master ~]# curl 10.110.82.62/hostname.html
19 my-test-app02-58cb6b67fc-w2nhc
20 [root@k8s-master ~]#
21 ##### 根据本机的IP访问
22 [root@k8s-master ~]# curl 172.16.1.110:30965/hostname.html
23 my-test-app02-58cb6b67fc-w2nhc
24 [root@k8s-master ~]#
25 [root@k8s-master ~]# curl 172.16.1.110:30965/hostname.html
26 my-test-app02-58cb6b67fc-4ss4v
values.yaml文件修改
1 [root@k8s-master my-test-app]# pwd
2 /root/k8s_practice/helm/my-test-app
3 [root@k8s-master my-test-app]#
4 [root@k8s-master my-test-app]# cat values.yaml
5 deployname: my-test-app02
6 replicaCount: 2
7 images:
8 repository: registry.cn-beijing.aliyuncs.com/google_registry/myapp
9 # 改了tag
10 tag: v3
重新release发布
1 [root@k8s-master my-test-app]# helm list
2 NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
3 mytest-app01 1 Thu Jul 16 21:18:08 2020 DEPLOYED my-test-app-v1.0.0 v2.2 default
4 [root@k8s-master my-test-app]#
5 [root@k8s-master my-test-app]# helm upgrade mytest-app01 . ### 如果在上级目录则为 helm upgrade mytest-app01 my-test-app/
6 Release "mytest-app01" has been upgraded.
7 LAST DEPLOYED: Thu Jul 16 21:32:25 2020
8 NAMESPACE: default
9 STATUS: DEPLOYED
10
11 RESOURCES:
12 ==> v1/Deployment
13 NAME READY UP-TO-DATE AVAILABLE AGE
14 my-test-app02 2/2 1 2 14m
15
16 ==> v1/Pod(related)
17 NAME READY STATUS RESTARTS AGE
18 my-test-app02-58cb6b67fc-4ss4v 1/1 Running 0 14m
19 my-test-app02-58cb6b67fc-w2nhc 1/1 Running 0 14m
20 my-test-app02-6b84df49bb-lpww7 0/1 ContainerCreating 0 0s
21
22 ==> v1/Service
23 NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
24 my-test-app NodePort 10.110.82.62 <none> 80:30965/TCP 14m
25
26
27 [root@k8s-master my-test-app]#
28 [root@k8s-master my-test-app]# helm list
29 NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
30 mytest-app01 2 Thu Jul 16 21:32:25 2020 DEPLOYED my-test-app-v1.0.0 v2.2 default
curl访问,可参见上面。可见app version已从v2改为了v3。
1、Helm官网地址
完毕!
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