[Posts] Kubernetes and Helm: Chart use the same deployment of multiple applications and Kubernetes Helm: Chart use the same deployment of multiple applications

Kubernetes and Helm: use the same Chart deploy multiple applications

https://www.cnblogs.com/dudu/p/12221724.html

k8s cluster build a good, ready to use on docker swarm migrate to k8s, but requires a written application yaml a profile, not only to write but also to write deployment.yaml service.yaml, and many application configuration is similar this tedious work was a bit prohibitive.

k8s there is no way to save it for this problem? I found a savior Helm - k8s application package manager, actual operating experience.

First mounted on the helm k8s master node, using the following command line 1 can handle.

curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash

Next, create a chart (chart is the helm of the bag)

helm create cnblogs-chart

Note: Prepare a number of different application deployment based on this chart.

helm creates a folder, let's look at the contents of the folder:

cnblogs-chart
├── charts
├── Chart.yaml
├── templates
│   ├── deployment.yaml
│   ├── _helpers.tpl
│   ├── ingress.yaml
│   ├── NOTES.txt
│   ├── serviceaccount.yaml
│   ├── service.yaml
│   └── tests
│       └── test-connection.yaml
└── values.yaml

About the use of these files, see the garden Bowen kubernetes actual articles of the helm example yaml file details .

The following modified in accordance with our deployment scenarios these profiles in the chart, because we want to use a chart with the deployment of a number of applications, the need to minimize repeatedly, so in the configuration will be based more on the convention. Assume that the application name we deploy a cache-api, it helm of release name also used cache-api, name docker mirror also use cache-api, name of the deployment and the service is also used cache-api, name ConfigMap is cache-api -appsettings.

Modifying the configuration templates (shared common configuration)

1) modify the configuration deployment.yaml

The metadata.name value is modified .Release.Name
Will be containers.name of value to .Release.Name
Will be containers. image of value to {{ .Release.Name }}:{{ .Values.image.version }}
Add containers. workingDir container working directory configuration
Add containers.command container configuration startup command
Add containers.env the environment variable configuration
Will matchLabels and labels values are changed {{ .Release.Name }}
Add the configMap mounted volume configuration for the application reads appsettings.Production.json.

metadata:
  name: {{ .Release.Name }}  labels:  name: {{ .Release.Name }} spec:  selector:  matchLabels:  app: {{ .Release.Name }}  template:  metadata:  labels:  app: {{ .Release.Name }}  spec:  containers:  - name: {{ .Release.Name }}  image: "{{ .Release.Name }}:{{ .Values.image.version }}"  workingDir: /app  command:  - sh  - run.sh  env:  - name: TZ  value: "Asia/Shanghai"  volumeMounts:  - name: appsettings  mountPath: /app/appsettings.Production.json  subPath: appsettings.Production.json  readOnly: true  volumes:  - name: appsettings  configMap:  name: "{{ .Release.Name }}-appsettings"

2) modify service.yaml

Also agreed with the application name name: {{ .Release.Name }}

kind: Service
metadata:
  name: {{ .Release.Name }}  labels:  name: {{ .Release.Name }} spec:  type: {{ .Values.service.type }}  ports:  - port: {{ .Values.service.port }}  targetPort: http  protocol: TCP  name: http  selector:  app: {{ .Release.Name }}

Modify values.yaml configuration (shared default configuration)

Will be image.pullPolicy revised to Always .
Add image.version and set latest .
In imagePullSecrets adding secret name.
Will be serviceAccount.create set to false.
In resources the limits with requests the CPU and memory limits provided.

replicaCount: 1

image:
  repository: {}  version: latest  pullPolicy: Always imagePullSecrets:  - name: regcred nameOverride: "" fullnameOverride: "" serviceAccount:  create: false  name: podSecurityContext: {} securityContext: {} service:  type: ClusterIP  port: 80 ingress:  enabled: false resources:  limits:  cpu: 2  memory: 2G  requests:  cpu: 100m  memory: 64Mi nodeSelector: {} tolerations: [] affinity: {}

Deploying Applications

1) Verify the configuration

Run the following command to verify the configuration is correct

helm install cache-api --set image.version=1.0 --dry-run --debug .

2) to deploy applications

If the configuration is validated, you can use the following command to deploy the application.

helm install cache-api --set image.version=1.0 .

Check deployed applications.

helm ls                                            
NAME        NAMESPACE   REVISION    UPDATED                                 STATUS      CHART               APP VERSION
cache-api   production  1           2020-01-22 17:17:30.414863452 +0800 CST deployed    cnblogs-chart-0.1.0 1

3) deployment of multiple applications

Can now deploy the chart based on a plurality of previously created applications, simply uploaded configuration parameters passed by the application helm install command, such as news-web deployment q-web with these two applications, the following command can be used are:

helm install news-web --set image.version=1.0.4,resources.limits.cpu=1 --dry-run --debug cnblogs-chart/
helm install ing-web --set image.version=1.3.11,resources.limits.cpu=1.5 --dry-run --debug cnblogs-chart/