K8S中部署Helm

Posted wangshuyang

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K8S中的包管理工具

1. 客户端Helm(即Helm)

 通过脚本安装:curl https://raw.githubusercontent.com/helm/helm/master/scripts/get > helm.sh,赋权运行:

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chmod +x helm.sh
./helm.sh

# 输出
Downloading https://kubernetes-helm.storage.googleapis.com/helm-v2.13.1-linux-amd64.tar.gz
Preparing to install helm and tiller into /usr/local/bin
helm installed into /usr/local/bin/helm
tiller installed into /usr/local/bin/tiller
Run ‘helm init‘ to configure helm.

# 验证
helm help

注:可能在执行脚本时出现curl: (7) Failed connect to kubernetes-helm.storage.googleapis.com:443; 网络不可达异常信息,多执行几次即可。

2. 服务端Tiller

直接helm init,即可在K8S集群中安装Tiller(在kube-system命名空间中),但执行的时虽然提示成功了,但K8S查看容器状态发现有Failed to pull image "gcr.io/kubernetes-helm/tiller:v2.13.1"....的异常,查看tiller-deployment的yaml文件发现容器的镜像为gcr.io/kubernetes-helm/tiller:v2.13.1,拉不到,去dockerhub上查看谷歌复制镜像命名空间中mirrorgooglecontainers是否有,没有又查看是否有用户镜像docker search tiller:v2.13.1,拉取一个用户的镜像,修改tag、删除旧的(建议在每个节点都干一下,选择器可能没有指定):

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docker pull hekai/gcr.io_kubernetes-helm_tiller_v2.13.1
docker tag hekai/gcr.io_kubernetes-helm_tiller_v2.13.1 gcr.io/kubernetes-helm/tiller:v2.13.1
docker rmi hekai/gcr.io_kubernetes-helm_tiller_v2.13.1

再次查看pod已经成功。

tiller授权:

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# 设置账号
kubectl create serviceaccount --namespace kube-system tiller
kubectl create clusterrolebinding tiller-cluster-rule --clusterrole=cluster-admin --serviceaccount=kube-system:tiller

# 使用 kubectl patch 更新 API 对象
kubectl patch deploy --namespace kube-system tiller-deploy -p ‘{"spec":{"template":{"spec":{"serviceAccount":"tiller"}}}}‘

# 查看授权是否成功
kubectl get deploy --namespace kube-system tiller-deploy --output yaml|grep serviceAccount

serviceAccount: tiller
serviceAccountName: tiller


helm version

Client: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}
Server: &version.Version{SemVer:"v2.13.1", GitCommit:"618447cbf203d147601b4b9bd7f8c37a5d39fbb4", GitTreeState:"clean"}

卸载tiller:helm resethelm reset --force

3. 使用

创建Helm chart(Helm中的包的形式叫做chart):

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# 拉取测试代码
git clone https://github.com/daemonza/testapi.git;

cd testapi
# 创建chart骨架
helm create testapi-chart

生成的chart骨架为:

testapi-chart
├── charts
├── Chart.yaml
├── templates
│ ├── deployment.yaml
│ ├── _helpers.tpl
│ ├── ingress.yaml
│ ├── NOTES.txt
| ├── service.yaml
│ └── tests
└── values.yaml

其中templates目录中存放的是K8S部署文件的模板,Chart.yaml文件如下:

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# chartAPI的版本,必须只能设为v1
apiVersion: v1
# 可选参数
appVersion: "1.0"
# 可选参数
description: A Helm chart for Kubernetes
# chart的名字,必选参数
name: testapi-chart
# chart的版本号,必选参数,必须符合SemVer
version: 0.1.0

其中values.yaml文件如下:

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# Default values for testapi-chart.
# This is a YAML-formatted file.
# Declare variables to be passed into your templates.

replicaCount: 1

image:
repository: nginx
tag: stable
pullPolicy: IfNotPresent

nameOverride: ""
fullnameOverride: ""

service:
type: ClusterIP
port: 80

ingress:
enabled: false
annotations: {}
# kubernetes.io/ingress.class: nginx
# kubernetes.io/tls-acme: "true"
hosts:
- host: chart-example.local
paths: []

tls: []
# - secretName: chart-example-tls
# hosts:
# - chart-example.local

resources: {}
# We usually recommend not to specify default resources and to leave this as a conscious
# choice for the user. This also increases chances charts run on environments with little
# resources, such as Minikube. If you do want to specify resources, uncomment the following
# lines, adjust them as necessary, and remove the curly braces after ‘resources:‘.
# limits:
# cpu: 100m
# memory: 128Mi
# requests:
# cpu: 100m
# memory: 128Mi

nodeSelector: {}

tolerations: []

affinity: {}

可以进入Chart.yaml所在目录运行Chart:

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cd testapi-chart

# 运行chart
helm lint

一切OK的话可以进行打包(在Chart.yaml的父目录外):

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# --debug标识可选,加上可以看到输出,testapi-chart是要打包的chart目录,打出的包在当前目录下
helm package testapi-chart --debug

# 输出
Successfully packaged chart and saved it to: /root/k8s/helm/testapi/testapi-chart-0.1.0.tgz
[debug] Successfully saved /root/k8s/helm/testapi/testapi-chart-0.1.0.tgz to /root/.helm/repository/local

现在打包出来在当前目录,也可以直接发布到本地的helm仓库:helm install testapi-chart-0.1.0.tgz,输出如下:

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NAME:   lumbering-zebu
LAST DEPLOYED: Fri Apr 26 18:54:26 2019
NAMESPACE: default
STATUS: DEPLOYED

RESOURCES:
==> v1/Deployment
NAME READY UP-TO-DATE AVAILABLE AGE
lumbering-zebu-testapi-chart 0/1 1 0 0s

==> v1/Pod(related)
NAME READY STATUS RESTARTS AGE
lumbering-zebu-testapi-chart-7fb48fc7b6-n6824 0/1 ContainerCreating 0 0s

==> v1/Service
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
lumbering-zebu-testapi-chart ClusterIP 10.97.1.55 <none> 80/TCP 0s


NOTES:
1. Get the application URL by running these commands:
export POD_NAME=$(kubectl get pods --namespace default -l "app.kubernetes.io/name=testapi-chart,app.kubernetes.io/instance=lumbering-zebu" -o jsonpath="{.items[0].metadata.name}")
echo "Visit http://127.0.0.1:8080 to use your application"
kubectl port-forward $POD_NAME 8080:80

上述就已经在K8S中创建了deployment,查看默认的命名空间就可以发现多了一个lumbering-zebu-testapi-chart的Deployment,可以查看deployment的包:

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helm ls

# 输出
NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
lumbering-zebu 1 Fri Apr 26 18:54:26 2019 DEPLOYED testapi-chart-0.1.0 1.0 default

修改Chart的打包版本0.1.0–>0.1.1,再次执行打包、发布,再次查看:

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kubectl get deployments

NAME READY UP-TO-DATE AVAILABLE AGE
lumbering-zebu-testapi-chart 1/1 1 1 13m
odd-chicken-testapi-chart 1/1 1 1 85s

出现2个了,现在需要删除旧版本的deployment的chart:helm delete lumbering-zebu-testapi-chart,通过helm lskubectl get pods可以发现旧版本的deployment都已经被删除。删除后同样可以回滚:

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# 将testapi包按顺序回滚1次修改,注意不带-testapi-chart
helm rollback lumbering-zebu 1
# 输出
Rollback was a success! Happy Helming!
# 验证
helm ls

但这种情况必须记得删除包的名字,实际可以通过helm ls --deleted查看已删除包的名字。

 升级,可以在修改相关的Chart.yaml文件后,直接在其所在目录运行helm upgrade odd-chicken .命令即可更新:

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# 验证
helm ls
# 版本号已变
NAME REVISION UPDATED STATUS CHART APP VERSION NAMESPACE
odd-chicken 2 Fri Apr 26 19:26:21 2019 DEPLOYED testapi-chart2-2.1.1 2.0 default

【设置Helm仓库】

 越来越觉得这东西像mvn了,Helm的仓库就是一个WEB服务器,如从charts目录提供helm服务:helm serve --repo-path ./charts。此外关于Chart服务的管理可能需要安装Monocular来提供WEB页面,安装步骤如下:

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# 拉取所需要的镜像
docker pull registry.cn-shanghai.aliyuncs.com/hhu/defaultbackend:1.4
docker tag registry.cn-shanghai.aliyuncs.com/hhu/defaultbackend:1.4 k8s.gcr.io/defaultbackend:1.4
docker rmi registry.cn-shanghai.aliyuncs.com/hhu/defaultbackend:1.4

# 安装Nginx Ingress controller
helm install stable/nginx-ingress --set controller.hostNetwork=true,rbac.create=true

# 添加源(最新的源)
helm repo add monocular https://helm.github.io/monocular
# 安装monocular
helm install monocular/monocular

然后等待,安装完了之后,即可通过

【使用Helm仓库】

 使用Helmet作为Helm仓库,可以将它部署到K8S集群中并添加Chart。

转自:https://blog.wgl.wiki/K8S%E4%B8%AD%E9%83%A8%E7%BD%B2Helm/

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