微服務和容器化給複雜應用部署與管理帶來了極大的挑戰。Helm是目前Kubernetes服務編排領域的唯一開源子項目,做爲Kubernetes應用的一個包管理工具,可理解爲Kubernetes的apt-get / yum,由Deis 公司發起,該公司已經被微軟收購。
Helm通過軟件打包的形式,支持發佈的版本管理和控制,很大程度上簡化了Kubernetes應用部署和管理的複雜性。
隨着業務容器化與向微服務架構轉變,通過分解巨大的單體應用爲多個服務的方式,分解了單體應用的複雜性,使每個微服務都可以獨立部署和擴展,實現了敏捷開發和快速迭代和部署。但任何事情都有兩面性,雖然微服務給我們帶來了很多便利,但由於應用被拆分成多個組件,導致服務數量大幅增加,對於Kubernetest編排來說,每個組件有自己的資源文件,並且可以獨立的部署與伸縮,這給採用Kubernetes做應用編排帶來了諸多挑戰:
- 管理、編輯與更新大量的K8s配置文件
- 部署一個含有大量配置文件的複雜K8s應用
- 分享和複用K8s配置和應用
- 參數化配置模板支持多個環境
- 管理應用的發佈:回滾、diff和查看發佈歷史
- 控制一個部署週期中的某一些環節
- 發佈後的驗證
而Helm恰好可以幫助我們解決上面問題。
Helm把Kubernetes資源(比如deployments、services或 ingress等) 打包到一個chart中,而chart被保存到chart倉庫。通過chart倉庫來存儲和分享chart。Helm使發佈可配置,支持發佈應用配置的版本管理,簡化了Kubernetes部署應用的版本控制、打包、發佈、刪除、更新等操作。
本文簡單介紹了Helm的用途、架構、安裝和使用。
用途
做爲Kubernetes的一個包管理工具,Helm具有如下功能:
- 創建新的chart
- chart打包成tgz格式
- 上傳chart到chart倉庫或從倉庫中下載chart
- 在Kubernetes集羣中安裝或卸載chart
- 管理用Helm安裝的chart的發佈週期
Helm有三個重要概念:
- chart:包含了創建Kubernetes的一個應用實例的必要信息
- config:包含了應用發佈配置信息
- release:是一個chart及其配置的一個運行實例
架構
組件
Helm有以下兩個組成部分:
- Helm Client是用戶命令行工具,其主要負責如下:
- 本地chart開發
- 倉庫管理
- 與Tiller sever交互
- 發送預安裝的chart
- 查詢release信息
- 要求升級或卸載已存在的release
- Tiller server是一個部署在Kubernetes集羣內部的server,其與Helm client、Kubernetes API server進行交互,主要負責如下:
- 監聽來自Helm client的請求
- 通過chart及其配置構建一次發佈
- 安裝chart到Kubernetes集羣,並跟蹤隨後的發佈
- 通過與Kubernetes交互升級或卸載chart
簡單的說,client管理charts,而server管理髮布release。
實現
- Helm client
- Helm client採用go語言編寫,採用
gRPC
協議與Tiller server交互。
- Helm client採用go語言編寫,採用
- Helm server
- Tiller server也同樣採用go語言編寫,提供了gRPC server與helm client進行交互,利用Kubernetes client 庫與Kubernetes進行通信,當前庫使用了
REST+JSON
格式。 - Tiller server 沒有自己的數據庫,目前使用Kubernetes的
ConfigMaps
存儲相關信息
- Tiller server也同樣採用go語言編寫,提供了gRPC server與helm client進行交互,利用Kubernetes client 庫與Kubernetes進行通信,當前庫使用了
說明:配置文件儘可能使用YAM格式
安裝
如果與我的情況不同,請閱讀官方的quick guide,了安裝的核心流程和多種情況。
前置條件
- kubernetes集羣
- 瞭解kubernetes的Context安全機制
- 下載helm的安裝包
wget https://storage.googleapis.com/kubernetes-helm/helm-v2.11.0-linux-amd64.tar.gz
配置ServiceAccount和規則
我的環境使用了RBAC(Role-Based Access Control )
的授權方式,需要先配置ServiceAccount和規則,然後再安裝helm。官方配置參考Role-based Access Control文檔。
配置helm全集羣權限
權限管理yml:
apiVersion: v1
kind: ServiceAccount
metadata:
name: tiller
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: tiller
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: tiller
namespace: kube-system
cluster-admin
是kubernetes默認創建的角色。不需要重新定義。
安裝helm:
$ kubectl create -f rbac-config.yaml
serviceaccount "tiller" created
clusterrolebinding "tiller" created
$ helm init --service-account tiller
運行結果:
$HELM_HOME has been configured at /root/.helm.
Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.
Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy.
To prevent this, run `helm init` with the --tiller-tls-verify flag.
For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation
Happy Helming!
實驗環境建議使用本方式安裝,然後安裝ingress-nginx等系統組件。
配置helm在一個namespace,管理另一個namespace
配置helm 安裝在helm-system
namespace,允許Tiller發佈應用到kube-public
namespace。
創建Tiller安裝namespace 和 ServiceAccount
創建helm-system
namespace,使用命令kubectl create namespace helm-system
定義ServiceAccount
---
kind: ServiceAccount
apiVersion: v1
metadata:
name: tiller
namespace: helm-system
Tiller管理namespace的角色和權限配置
創建一個Role,擁有namespace kube-public
的所有權限。將Tiller的ServiceAccount綁定到這個角色上,允許Tiller 管理kube-public
namespace 所有的資源。
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-manager
namespace: kube-public
rules:
- apiGroups: ["", "extensions", "apps"]
resources: ["*"]
verbs: ["*"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-binding
namespace: kube-public
subjects:
- kind: ServiceAccount
name: tiller
namespace: helm-system
roleRef:
kind: Role
name: tiller-manager
apiGroup: rbac.authorization.k8s.io
Tiller內部的Release信息管理
Helm中的Release信息存儲在Tiller安裝的namespace中的ConfigMap
,即helm-system
,需要允許Tiller操作helm-system
的ConfigMap
。所以創建Role helm-system.tiller-manager
,並綁定到ServiceAccounthelm-system.tiller
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
namespace: helm-system
name: tiller-manager
rules:
- apiGroups: ["", "extensions", "apps"]
resources: ["configmaps"]
verbs: ["*"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: tiller-binding
namespace: helm-system
subjects:
- kind: ServiceAccount
name: tiller
namespace: helm-system
roleRef:
kind: Role
name: tiller-manager
apiGroup: rbac.authorization.k8s.io
init helm
使用命令`helm init --service-account tiller --tiller-namespace helm-system`安裝helm。
helm init
參數說明:
--service-account
:指定helm Tiller的ServiceAccount,對於啓用了kubernetesRBAC的集羣適用。--tiller-namespace
:將helm 安裝到指定的namespace中;--tiller-image
:指定helm鏡像--kube-context
:將helm Tiller安裝到特定的kubernetes集羣中;
第一次運行出現問題:
[root@kuber24 helm]# helm init --service-account tiller --tiller-namespace helm-system
Creating /root/.helm
Creating /root/.helm/repository
Creating /root/.helm/repository/cache
Creating /root/.helm/repository/local
Creating /root/.helm/plugins
Creating /root/.helm/starters
Creating /root/.helm/cache/archive
Creating /root/.helm/repository/repositories.yaml
Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com
Error: Looks like "https://kubernetes-charts.storage.googleapis.com" is not a valid chart repository or cannot be reached: Get https://kubernetes-charts.storage.googleapis.com/index.yaml: EOF
這個是由於google的都被牆了,修改Hosts,指定storage.googleapis.com
對應的課訪問的IP即可。最新的國內可訪問google的Hosts配置見github項目googlehosts/hosts的hosts/hosts-files/hosts文件。
再次運行init helm命令,成功安裝。
[root@kuber24 helm]# helm init --service-account tiller --tiller-namespace helm-system
Creating /root/.helm/repository/repositories.yaml
Adding stable repo with URL: https://kubernetes-charts.storage.googleapis.com
Adding local repo with URL: http://127.0.0.1:8879/charts
$HELM_HOME has been configured at /root/.helm.
Tiller (the Helm server-side component) has been installed into your Kubernetes Cluster.
Please note: by default, Tiller is deployed with an insecure 'allow unauthenticated users' policy.
To prevent this, run `helm init` with the --tiller-tls-verify flag.
For more information on securing your installation see: https://docs.helm.sh/using_helm/#securing-your-helm-installation
Happy Helming!
查看Tiller的Pod狀態時,發現Pod出現錯誤ImagePullBackOff
,如下:
[root@kuber24 resources]# kubectl get pods --all-namespaces|grep tiller
helm-system tiller-deploy-cdcd5dcb5-fqm57 0/1 ImagePullBackOff 0 13m
查看pod的詳細信息kubectl describe pod tiller-deploy-cdcd5dcb5-fqm57 -n helm-system
,發現Pod依賴鏡像gcr.io/kubernetes-helm/tiller:v2.11.0
。
查詢docker hub上是否有人複製過改鏡像,如圖:
[root@kuber24 ~]# docker search tiller:v2.11.0
INDEX NAME DESCRIPTION STARS OFFICIAL AUTOMATED
docker.io docker.io/jay1991115/tiller gcr.io/kubernetes-helm/tiller:v2.11.0 1 [OK]
docker.io docker.io/luyx30/tiller tiller:v2.11.0 1 [OK]
docker.io docker.io/1017746640/tiller FROM gcr.io/kubernetes-helm/tiller:v2.11.0 0 [OK]
docker.io docker.io/724399396/tiller gcr.io/kubernetes-helm/tiller:v2.11.0-rc.2... 0 [OK]
docker.io docker.io/fengzos/tiller gcr.io/kubernetes-helm/tiller:v2.11.0 0 [OK]
docker.io docker.io/imwower/tiller tiller from gcr.io/kubernetes-helm/tiller:... 0 [OK]
docker.io docker.io/xiaotech/tiller FROM gcr.io/kubernetes-helm/tiller:v2.11.0 0 [OK]
docker.io docker.io/yumingc/tiller tiller:v2.11.0 0 [OK]
docker.io docker.io/zhangc476/tiller gcr.io/kubernetes-helm/tiller/kubernetes-h... 0 [OK]
同樣使用hub.docker.com
上mirrorgooglecontainers
加速的google鏡像,然後改鏡像的名字。每個Node節點都需要安裝。
安裝問題
鏡像問題
鏡像下載不下來:使用他人同步到docker hub上面的鏡像;使用docker search $NAME:$VERSION
安裝helm提示repo連接不上
使用Hosts翻牆實現。
下載Chart問題
問題提示:
[root@kuber24 ~]# helm install nginx --tiller-namespace helm-system --namespace kube-public
Error: failed to download "nginx" (hint: running `helm repo update` may help)
使用helm repo update
後,並沒有解決問題。
如下:
[root@kuber24 ~]# helm install nginx --tiller-namespace helm-system --namespace kube-public
Error: failed to download "nginx" (hint: running `helm repo update` may help)
[root@kuber24 ~]# helm repo update
Hang tight while we grab the latest from your chart repositories...
...Skip local chart repository
...Successfully got an update from the "stable" chart repository
Update Complete. ⎈ Happy Helming!⎈
[root@kuber24 ~]# helm install nginx --tiller-namespace helm-system --namespace kube-public
Error: failed to download "nginx" (hint: running `helm repo update` may help)
可能的原因:
- 沒有nginx這個chart:使用
helm search nginx
查詢nginx chart信息。 - 網絡連接問題,下載不了。這種情況下,等待一定超時後,helm會提示。
使用
添加常見的repo
添加aliyun, github 和官方incubator charts repository。
helm add repo gitlab https://charts.gitlab.io/
helm repo add aliyun https://kubernetes.oss-cn-hangzhou.aliyuncs.com/charts
helm repo add incubator https://kubernetes-charts-incubator.storage.googleapis.com/
日常使用
本小結的$NAME
表示helm的repo/chart_name。
- 查詢charts:
helm search $NAME
- 查看release的列表:
helm ls [--tiller-namespace $TILLER_NAMESPACE]
- 查詢package 信息:
helm inspect $NAME
- 查詢package支持的選項:
helm inspect values $NAME
- 部署chart:
helm install $NAME [--tiller-namespace $TILLER_NAMESPACE] [--namespace $CHART_DEKPLOY_NAMESPACE]
- 刪除release:
helm delete $RELEASE_NAME [--purge] [--tiller-namespace $TILLER_NAMESPACE]
- 更新:
helm upgrade --set $PARAM_NAME=$PARAM_VALUE $RELEASE_NAME $NAME [--tiller-namespace $TILLER_NAMESPACE]
- 回滾:
helm rollback $RELEASE_NAME $REVERSION [--tiller-namespace $TILLER_NAMESPACE]
刪除release時,不使用
--purge
參數,會僅撤銷pod部署,不會刪除release的基本信息,不能release同名的chart。
部署RELEASE
部署mysql時,查詢參數並配置相應的參數。
查詢可配置的參數:
[root@kuber24 charts]# helm inspect values aliyun/mysql
## mysql image version
## ref: https://hub.docker.com/r/library/mysql/tags/
##
image: "mysql"
imageTag: "5.7.14"
## Specify password for root user
##
## Default: random 10 character string
# mysqlRootPassword: testing
## Create a database user
##
# mysqlUser:
# mysqlPassword:
## Allow unauthenticated access, uncomment to enable
##
# mysqlAllowEmptyPassword: true
## Create a database
##
# mysqlDatabase:
## Specify an imagePullPolicy (Required)
## It's recommended to change this to 'Always' if the image tag is 'latest'
## ref: http://kubernetes.io/docs/user-guide/images/#updating-images
##
imagePullPolicy: IfNotPresent
livenessProbe:
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 3
readinessProbe:
initialDelaySeconds: 5
periodSeconds: 10
timeoutSeconds: 1
successThreshold: 1
failureThreshold: 3
## Persist data to a persistent volume
persistence:
enabled: true
## database data Persistent Volume Storage Class
## If defined, storageClassName: <storageClass>
## If set to "-", storageClassName: "", which disables dynamic provisioning
## If undefined (the default) or set to null, no storageClassName spec is
## set, choosing the default provisioner. (gp2 on AWS, standard on
## GKE, AWS & OpenStack)
##
# storageClass: "-"
accessMode: ReadWriteOnce
size: 8Gi
## Configure resource requests and limits
## ref: http://kubernetes.io/docs/user-guide/compute-resources/
##
resources:
requests:
memory: 256Mi
cpu: 100m
# Custom mysql configuration files used to override default mysql settings
configurationFiles:
# mysql.cnf: |-
# [mysqld]
# skip-name-resolve
## Configure the service
## ref: http://kubernetes.io/docs/user-guide/services/
service:
## Specify a service type
## ref: https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services---service-types
type: ClusterIP
port: 3306
# nodePort: 32000
例如我們需要配置mysql的root密碼,那麼可以直接使用--set
參數設置選項,例如roo密碼設置:--set mysqlRootPassword=hgfgood
。
通過mysql選項的說明中persistence
參數,可以看出mysql 需要持久化存儲,所以需要給kubernetes配置持久化存儲卷PV。
創建PV:
[root@kuber24 resources]# cat local-pv.yml
apiVersion: v1
kind: PersistentVolume
metadata:
name: local-pv
namespace: kube-public
spec:
capacity:
storage: 30Gi
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Recycle
hostPath:
path: /home/k8s
完整的release chart命令如下:helm install --name mysql-dev --set mysqlRootPassword=hgfgood aliyun/mysql --tiller-namespace helm-system --namespace kube-public
。
查看已經release的chart列表:
[root@kuber24 charts]# helm ls --tiller-namespace=helm-system
NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
mysql-dev 1 Fri Oct 26 10:35:55 2018 DEPLOYED mysql-0.3.5 kube-public
正常情況下,dashboard監控的情況如下圖:
運行此mysql chart 需要busybox鏡像,偶爾會出現下圖所示的問題,這是docker默認訪問國外的docker hub導致的。需要先下載busybox鏡像。
更新和回滾
上例中,安裝完mysql,使用的root密碼爲hgfgood
。本例中將其更新爲hgf
然後回滾到原始的密碼hgfgood
。
查詢mysql安裝後的密碼:
[root@kuber24 charts]# kubectl get secret --namespace kube-public mysql-dev-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo
hgfgood
更新mysql的root密碼,helm upgrade --set mysqlRootPassword=hgf mysql-dev mysql --tiller-namespace helm-system
更新完成後再次查詢mysql的root用戶密碼
[root@kuber24 charts]# kubectl get secret --namespace kube-public mysql-dev-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo
hgf
查看RELEASE的信息:
[root@kuber24 charts]# helm ls --tiller-namespace helm-system
NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
mysql-dev 2 Fri Oct 26 11:26:48 2018 DEPLOYED mysql-0.3.5 kube-public
查看REVISION
,可以目前mysql-dev
有兩個版本。
回滾到版本1
:
[root@kuber24 charts]# helm rollback mysql-dev 1 --tiller-namespace helm-system
Rollback was a success! Happy Helming!
[root@kuber24 charts]# kubectl get secret --namespace kube-public mysql-dev-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo
hgfgood
通過上述輸出可以發現RELEASE已經回滾。
常見問題
Error: could not find tiller
,使用helm client,需要與tiller 交互時,需要制定tiller的namespace,使用參數--tiller-namespace helm-system
,此參數默認時kube-system
。
境內chart下載失敗的問題
由於網絡問題下載會失敗的問題,例如:
[root@kuber24 ~]# helm install stable/mysql --tiller-namespace helm-system --namespace kube-public --debug
[debug] Created tunnel using local port: '32774'
[debug] SERVER: "127.0.0.1:32774"
[debug] Original chart version: ""
Error: Get https://kubernetes-charts.storage.googleapis.com/mysql-0.10.2.tgz: read tcp 10.20.13.24:56594->216.58.221.240:443: read: connection reset by peer
- 進入本地charts保存的目錄
- 使用阿里雲fetch對應的chart
例如 安裝mysql。
helm fetch aliyun/mysql --untar
[root@kuber24 charts]# ls
mysql
[root@kuber24 charts]# ls mysql/
Chart.yaml README.md templates values.yaml
然後再次運行helm install
安裝mysql chart。
helm install mysql --tiller-namespace helm-system --namespace kube-public
可以使用--debug
參數,打開debug信息。
[root@kuber24 charts]# helm install mysql --tiller-namespace helm-system --namespace kube-public --debug
[debug] Created tunnel using local port: '41905'
[debug] SERVER: "127.0.0.1:41905"
[debug] Original chart version: ""
[debug] CHART PATH: /root/Downloads/charts/mysql
NAME: kissable-bunny
REVISION: 1
RELEASED: Thu Oct 25 20:20:23 2018
CHART: mysql-0.3.5
USER-SUPPLIED VALUES:
{}
COMPUTED VALUES:
configurationFiles: null
image: mysql
imagePullPolicy: IfNotPresent
imageTag: 5.7.14
livenessProbe:
failureThreshold: 3
initialDelaySeconds: 30
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 5
persistence:
accessMode: ReadWriteOnce
enabled: true
size: 8Gi
readinessProbe:
failureThreshold: 3
initialDelaySeconds: 5
periodSeconds: 10
successThreshold: 1
timeoutSeconds: 1
resources:
requests:
cpu: 100m
memory: 256Mi
service:
port: 3306
type: ClusterIP
HOOKS:
MANIFEST:
---
# Source: mysql/templates/secrets.yaml
apiVersion: v1
kind: Secret
metadata:
name: kissable-bunny-mysql
labels:
app: kissable-bunny-mysql
chart: "mysql-0.3.5"
release: "kissable-bunny"
heritage: "Tiller"
type: Opaque
data:
mysql-root-password: "TzU5U2tScHR0Sg=="
mysql-password: "RGRXU3Ztb3hQNw=="
---
# Source: mysql/templates/pvc.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: kissable-bunny-mysql
labels:
app: kissable-bunny-mysql
chart: "mysql-0.3.5"
release: "kissable-bunny"
heritage: "Tiller"
spec:
accessModes:
- "ReadWriteOnce"
resources:
requests:
storage: "8Gi"
---
# Source: mysql/templates/svc.yaml
apiVersion: v1
kind: Service
metadata:
name: kissable-bunny-mysql
labels:
app: kissable-bunny-mysql
chart: "mysql-0.3.5"
release: "kissable-bunny"
heritage: "Tiller"
spec:
type: ClusterIP
ports:
- name: mysql
port: 3306
targetPort: mysql
selector:
app: kissable-bunny-mysql
---
# Source: mysql/templates/deployment.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: kissable-bunny-mysql
labels:
app: kissable-bunny-mysql
chart: "mysql-0.3.5"
release: "kissable-bunny"
heritage: "Tiller"
spec:
template:
metadata:
labels:
app: kissable-bunny-mysql
spec:
initContainers:
- name: "remove-lost-found"
image: "busybox:1.25.0"
imagePullPolicy: "IfNotPresent"
command: ["rm", "-fr", "/var/lib/mysql/lost+found"]
volumeMounts:
- name: data
mountPath: /var/lib/mysql
containers:
- name: kissable-bunny-mysql
image: "mysql:5.7.14"
imagePullPolicy: "IfNotPresent"
resources:
requests:
cpu: 100m
memory: 256Mi
env:
- name: MYSQL_ROOT_PASSWORD
valueFrom:
secretKeyRef:
name: kissable-bunny-mysql
key: mysql-root-password
- name: MYSQL_PASSWORD
valueFrom:
secretKeyRef:
name: kissable-bunny-mysql
key: mysql-password
- name: MYSQL_USER
value: ""
- name: MYSQL_DATABASE
value: ""
ports:
- name: mysql
containerPort: 3306
livenessProbe:
exec:
command:
- sh
- -c
- "mysqladmin ping -u root -p${MYSQL_ROOT_PASSWORD}"
initialDelaySeconds: 30
periodSeconds: 10
timeoutSeconds: 5
successThreshold: 1
failureThreshold: 3
readinessProbe:
exec:
command:
- sh
- -c
- "mysqladmin ping -u root -p${MYSQL_ROOT_PASSWORD}"
initialDelaySeconds: 5
periodSeconds: 10
timeoutSeconds: 1
successThreshold: 1
failureThreshold: 3
volumeMounts:
- name: data
mountPath: /var/lib/mysql
volumes:
- name: data
persistentVolumeClaim:
claimName: kissable-bunny-mysql
LAST DEPLOYED: Thu Oct 25 20:20:23 2018
NAMESPACE: kube-public
STATUS: DEPLOYED
RESOURCES:
==> v1/Pod(related)
NAME READY STATUS RESTARTS AGE
kissable-bunny-mysql-c7df69d65-lmjzn 0/1 Pending 0 0s
==> v1/Secret
NAME AGE
kissable-bunny-mysql 1s
==> v1/PersistentVolumeClaim
kissable-bunny-mysql 1s
==> v1/Service
kissable-bunny-mysql 1s
==> v1beta1/Deployment
kissable-bunny-mysql 1s
NOTES:
MySQL can be accessed via port 3306 on the following DNS name from within your cluster:
kissable-bunny-mysql.kube-public.svc.cluster.local
To get your root password run:
MYSQL_ROOT_PASSWORD=$(kubectl get secret --namespace kube-public kissable-bunny-mysql -o jsonpath="{.data.mysql-root-password}" | base64 --decode; echo)
To connect to your database:
1. Run an Ubuntu pod that you can use as a client:
kubectl run -i --tty ubuntu --image=ubuntu:16.04 --restart=Never -- bash -il
2. Install the mysql client:
$ apt-get update && apt-get install mysql-client -y
3. Connect using the mysql cli, then provide your password:
$ mysql -h kissable-bunny-mysql -p
To connect to your database directly from outside the K8s cluster:
MYSQL_HOST=127.0.0.1
MYSQL_PORT=3306
# Execute the following commands to route the connection:
export POD_NAME=$(kubectl get pods --namespace kube-public -l "app=kissable-bunny-mysql" -o jsonpath="{.items[0].metadata.name}")
kubectl port-forward $POD_NAME 3306:3306
mysql -h ${MYSQL_HOST} -P${MYSQL_PORT} -u root -p${MYSQL_ROOT_PASSWORD}
打包Chart
- [ ] 詳細的打包實驗。
# 創建一個新的 chart
helm create hello-chart
# validate chart
helm lint
# 打包 chart 到 tgz
helm package hello-chart
參考
最後
感謝大家的閱讀,如果有什麼問題️,請您留言。
歡迎大家來我的github,查看更多關於kubernetes的個人經驗,共同進步。
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