一、简介
- Helm
Helm 是 Kubernetes 的包管理器。 - Chart
Helm使用的包格式称为 chart。chart存储在Chart Repository。
chart就是一个描述Kubernetes相关资源的文件集合。单个chart可以用来部署一些简单的， 类似于memcache pod，或者某些复杂的HTTP服务器以及web全栈应用、数据库、缓存等等。 - Release
基于Chart运行的实例叫做Release
在 Kubernetes 集群上运行的 Chart 的一个实例。在同一个集群上，一个 Chart 可以安装很多次。每次安装都会创建一个新的 release。
例如一个 MySQL Chart，如果想在服务器上运行两个数据库，就可以把这个 Chart 安装两次。每次安装都会生成自己的 Release，会有自己的 Release 名称。 - Repository
用于发布和存储 Chart 的仓库。
二、chart的组成
chart主要包含的资源配置文件，但这些文件通常不是原生格式的配置，而内嵌了大量的模板字串，以给用户提供自定义配置的接口;
为了简化了需要配置模板字串，Chart还会为这些模板字串提供默认值，存一个yaml格式的文件中“values.yml”，因此，也称其为值文件;
-
Chart 文件结构
chart是一个组织在文件目录中的集合。目录名称就是chart名称（没有版本信息）。因而描述WordPress的chart可以存储在wordpress/目录中。
在这个目录中，Helm 期望可以匹配以下结构：wordpress/ Chart.yaml # 文件包含了该chart的描述。你可以从模板中访问它。charts/目录 可以包含其他的chart(称之为 子chart)。 LICENSE # 可选: 包含chart许可证的纯文本文件 README.md # 可选: 可读的README文件 values.yaml # chart 默认的配置值，这个文件包含了chart的默认值 。这些值会在用户执行helm install 或 helm upgrade时被覆盖。 values.schema.json # 可选: 一个使用JSON结构的values.yaml文件 charts/ # 包含chart依赖的其他chart crds/ # 自定义资源的定义 templates/ # 模板目录， 当和values 结合时，可生成有效的Kubernetes manifest文件，当Helm评估chart时，会通过模板渲染引擎将所有文件发送到templates/目录中。 然后收集模板的结果并发送给Kubernetes。 templates/NOTES.txt # 可选: 包含简要使用说明的纯文本文件 -
chart获取
可从社区中获取 (https://artifacthub.io/)，也可自行创建，并通过社区分发
需要先将Chart Repository的信息配置在Helm上才能从中下载
ChartChart保存在本地缓存中
三、安装Helm
https://github.com/helm/helm
root@k8s-master01:~# curl -LO https://get.helm.sh/helm-v3.14.0-linux-amd64.tar.gz
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 15.3M 100 15.3M 0 0 47832 0 0:05:37 0:05:37 --:--:-- 111k
root@k8s-master01:~# tar xf helm-v3.14.0-linux-amd64.tar.gz
root@k8s-master01:~# ls
helm-v3.14.0-linux-amd64.tar.gz jiva-operator.yaml kube-flannel.yml learning-k8s linux-amd64 nfs-pvc.yaml snap storageclass-nfs.yaml test
root@k8s-master01:~# cd linux-amd64/
root@k8s-master01:~/linux-amd64# ls
LICENSE README.md helm
root@k8s-master01:~/linux-amd64# mv helm /usr/local/bin/
root@k8s-master01:~/linux-amd64# cd ..
root@k8s-master01:~# ls
helm-v3.14.0-linux-amd64.tar.gz jiva-operator.yaml kube-flannel.yml learning-k8s linux-amd64 nfs-pvc.yaml snap storageclass-nfs.yaml test
root@k8s-master01:~# rm -rf linux-amd64/
四、Helm命令
Helm的一般操作：
helm search: 搜索chart
helm pull: 下载chart到本地目录查看
helm install: 上传chart到Kubernetes
helm list: 列出已发布的chart
从本地的仓库中查找应用，由于本地仓库没有配置故无法搜索到
root@k8s-master01:~# helm search repo mysql
Error: no repositories configured
从Helm Hub中查找Chart，这些Chart来自于注册到Helm Hub中的各个仓库。
helm search hub mysql
URL CHART VERSION APP VERSION DESCRIPTION
https://artifacthub.io/packages/helm/saber/mysql 8.8.21 8.0.27 Chart to create a Highly available MySQL cluster
https://artifacthub.io/packages/helm/ygqygq2/mysql 9.5.0 8.0.32 MySQL is a fast, reliable, scalable, and easy t...
https://artifacthub.io/packages/helm/mysql/mysql 2.1.3 8.0.26 deploy mysql standalone or group-replication He...
https://artifacthub.io/packages/helm/kubegems/m... 8.9.6 8.0.29 MySQL is a fast, reliable, scalable, and easy t...
https://artifacthub.io/packages/helm/kvalitetsi... 9.10.4 8.0.33 MySQL is a fast, reliable, scalable, and easy t...
https://artifacthub.io/packages/helm/groundhog2... 1.1.1 8.2.0 A Helm chart for MySQL on Kubernetes
https://artifacthub.io/packages/helm/cloudnativ... 5.0.1 8.0.16 Chart to create a Highly available MySQL cluster
https://artifacthub.io/packages/helm/kubesphere... 1.0.2 5.7.33 High Availability MySQL Cluster, Open Source.
https://artifacthub.io/packages/helm/bitnami/mysql 9.18.0 8.0.36 MySQL is a fast, reliable, scalable, and easy t...
https://artifacthub.io/packages/helm/bitnami-ak... 9.4.3 8.0.31 MySQL is a fast, reliable, scalable, and easy t...
...
五、基于Helm部署mysql
1、社区网站搜索mysql chart
2、准备安装mysql依赖的存储类
存储类的环境准备参考[https://www.cnblogs.com/OpenSourceSite/p/17969118],需要准备：
openebs-hostpath：提供本地卷存储
openebs-jiva-csi：提供复制卷
openebs-rwx：提供多路读写的卷
root@k8s-master01:~# kubectl get pod -n openebs
NAME READY STATUS RESTARTS AGE
jiva-operator-5d8846bc49-5x2d2 1/1 Running 0 9d
nfs-pvc-62db4f63-df95-4815-b7f0-7f41c116aa31-7c575fd444-2k9rc 1/1 Running 0 8d
openebs-jiva-csi-controller-0 5/5 Running 201 (142m ago) 9d
openebs-jiva-csi-node-5t6pt 3/3 Running 0 9d
openebs-jiva-csi-node-cv6x8 3/3 Running 0 5d18h
openebs-jiva-csi-node-xqqbl 3/3 Running 0 9d
openebs-localpv-provisioner-6787b599b9-ns4nt 1/1 Running 198 (142m ago) 9d
openebs-ndm-cluster-exporter-7bfd5746f4-v97jr 1/1 Running 0 9d
openebs-ndm-h9vkc 1/1 Running 0 9d
openebs-ndm-node-exporter-4hplz 1/1 Running 0 5d18h
openebs-ndm-node-exporter-7zrl2 1/1 Running 0 9d
openebs-ndm-node-exporter-bt6kb 1/1 Running 0 9d
openebs-ndm-operator-845b8858db-9b6m5 1/1 Running 0 9d
openebs-ndm-qqwv4 1/1 Running 0 9d
openebs-ndm-vkcxc 1/1 Running 0 5d18h
openebs-nfs-provisioner-5b595f4798-2ft9w 1/1 Running 93 (142m ago) 9d
pvc-4134b8fc-8918-4076-88fa-89da76dead3b-jiva-ctrl-d77d67dhdppw 2/2 Running 0 8d
pvc-4134b8fc-8918-4076-88fa-89da76dead3b-jiva-rep-0 1/1 Running 0 8d
pvc-4134b8fc-8918-4076-88fa-89da76dead3b-jiva-rep-1 1/1 Running 0 8d
root@k8s-master01:~# kubectl get sc
NAME PROVISIONER RECLAIMPOLICY VOLUMEBINDINGMODE ALLOWVOLUMEEXPANSION AGE
local kubernetes.io/no-provisioner Delete WaitForFirstConsumer false 3d19h
nfs-csi nfs.csi.k8s.io Delete Immediate false 2d20h
openebs-device openebs.io/local Delete WaitForFirstConsumer false 9d
openebs-hostpath openebs.io/local Delete WaitForFirstConsumer false 9d
openebs-jiva-csi jiva.csi.openebs.io Delete Immediate true 9d
openebs-rwx openebs.io/nfsrwx Delete Immediate false 9d
3、基于dockerhub上的oci仓库部署mysql
helm install mysql \
--set auth.rootPassword='mysql' \
--set global.storageClass=openebs-hostpath \
--set architecture=replication \
--set auth.database=wpdb \
--set auth.username=wpuser \
--set auth.password='mysql' \
--set secondary.replicaCount=1 \
--set auth.replicationPassword='replpass' \
oci://registry-1.docker.io/bitnamicharts/mysql \
-n app --create-namespace
root@k8s-master01:~# helm install mysql \
--set auth.rootPassword='mysql' \
--set global.storageClass=openebs-hostpath \
--set architecture=replication \
--set auth.database=wpdb \
--set auth.username=wpuser \
--set auth.password='mysql' \
--set secondary.replicaCount=1 \
--set auth.replicationPassword='replpass' \
oci://registry-1.docker.io/bitnamicharts/mysql \
-n app --create-namespace
Pulled: registry-1.docker.io/bitnamicharts/mysql:9.18.0
Digest: sha256:464bb1d8027b7650472d363c234df2af9210410961c64b18753200367c794e5e
NAME: mysql
LAST DEPLOYED: Sun Jan 28 17:40:03 2024
NAMESPACE: app
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
CHART NAME: mysql
CHART VERSION: 9.18.0
APP VERSION: 8.0.36
** Please be patient while the chart is being deployed **
Tip:
Watch the deployment status using the command: kubectl get pods -w --namespace app
Services:
echo Primary: mysql-primary.app.svc.cluster.local:3306
echo Secondary: mysql-secondary.app.svc.cluster.local:3306
Execute the following to get the administrator credentials:
echo Username: root
MYSQL_ROOT_PASSWORD=$(kubectl get secret --namespace app mysql -o jsonpath="{.data.mysql-root-password}" | base64 -d)
To connect to your database:
1. Run a pod that you can use as a client:
kubectl run mysql-client --rm --tty -i --restart='Never' --image docker.io/bitnami/mysql:8.0.36-debian-11-r0 --namespace app --env MYSQL_ROOT_PASSWORD=$MYSQL_ROOT_PASSWORD --command -- bash
2. To connect to primary service (read/write):
mysql -h mysql-primary.app.svc.cluster.local -uroot -p"$MYSQL_ROOT_PASSWORD"
3. To connect to secondary service (read-only):
mysql -h mysql-secondary.app.svc.cluster.local -uroot -p"$MYSQL_ROOT_PASSWORD"
root@k8s-master01:~#
- 查看部署的版本
root@k8s-master01:~# helm list -n app
NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
mysql app 1 2024-01-28 17:40:03.544271842 +0800 CST deployed mysql-9.18.0 8.0.36
- 查看默认使用模板渲染之后的配置文件
root@k8s-master01:~# helm get manifest mysql -n app
---
# Source: mysql/templates/serviceaccount.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: mysql
namespace: "app"
labels:
app.kubernetes.io/instance: mysql
app.kubernetes.io/managed-by: Helm
app.kubernetes.io/name: mysql
app.kubernetes.io/version: 8.0.36
helm.sh/chart: mysql-9.18.0
automountServiceAccountToken: false
secrets:
- name: mysql
---
# Source: mysql/templates/secrets.yaml
apiVersion: v1
kind: Secret
metadata:
name: mysql
namespace: "app"
labels:
app.kubernetes.io/instance: mysql
app.kubernetes.io/managed-by: Helm
app.kubernetes.io/name: mysql
app.kubernetes.io/version: 8.0.36
helm.sh/chart: mysql-9.18.0
type: Opaque
data:
mysql-root-password: "bXlzcWw="
mysql-password: "bXlzcWw="
mysql-replication-password: "cmVwbHBhc3M="
- 查看用户自定义的参数的值
root@k8s-master01:~# helm get values mysql -n app
USER-SUPPLIED VALUES:
architecture: replication
auth:
database: wpdb
password: mysql
replicationPassword: replpass
rootPassword: mysql
username: wpuser
global:
storageClass: openebs-hostpath
secondary:
replicaCount: 1
- 查看部署的mysql
root@k8s-master01:~# kubectl get pod -n app
NAME READY STATUS RESTARTS AGE
mysql-primary-0 1/1 Running 0 3m23s
mysql-secondary-0 1/1 Running 0 3m23s
root@k8s-master01:~# kubectl exec -it mysql-primary-0 -n app bash
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
I have no name!@mysql-primary-0:/$
I have no name!@mysql-primary-0:/$ mysql -uroot -hlocalhost -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 290
Server version: 8.0.36 Source distribution
Copyright (c) 2000, 2024, Oracle and/or its affiliates.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> SHOW DATABASES;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
| wpdb |
+--------------------+
5 rows in set (0.01 sec)