使用Helm简化K8S应用管理

一、背景介绍

随着第二阶段各平台模块的微服务化改造工作的推进，预计每个namespace会分别增加30-40个工作负载，因此需要维护的yaml文件将急剧扩展，手工维护已不现实。因此使用helm来维护k8s应用被提上议事日程。

关于helm的配置文件语法及服务端配置请参考官网手册： https://helm.sh/docs/

二、需求分析

1、公共配置类
Configmap

每个namespace至少有两个configmap，其中center-config存储了各个环境的 mysql 、 mongodb 、 redis 等基础公共服务的IP、用户名和密码、连接池配置信息等，我们通过集中配置解耦做到代码编译一次镜像，各个环境都能运行。

hb-lan-server-xml文件实际上就是tomcat下面的server.xml文件，由于早前代码上使用redis做登陆session，需要修改server.xml，因此需要对这个文件做解耦配置，后续创建的工作负载通过外挂的形式替换镜像层中的server.xml文件。

Secret

每个namespace都会存在harborsecret的token，顾名思义就是harbor仓库拉取镜像使用的权限信息，否则创建工作负载的时候会无法拉取镜像。

pv\pvc

每个namespace都有一个配套共享存储，用来统一存放用户上传的附件资源，内网环境我们通过nfs来实现。

rbac相关

因为应用程序会通过curl k8s的master来获取一些配置类的信息，如果没有做相应的rbac授权，访问会出现401，因此需要对每个namespace下的default sa用户做rbac授权。

2、工作负载类

工作负载目前统一为无状态工作负载，主要分为两类，一类需要对外暴露域名和端口，另一类程序内部通过zk进行dubbo调用

三、配置helm与测试

1、公共配置类

# helm create basic
# cd basic
# helm create namespace
# rm -rf charts/namespace/templates/*

# cat charts/namespace/values.yaml 
# Default values for namespace.
# This is a YAML-formatted file.
# Declare variables to be passed into your templates.

namespace: default

# cat charts/namespace/templates/namespace.yaml 
apiVersion: v1
kind: Namespace
metadata:
 name: {{ .Values.namespace }}

# cat charts/namespace/templates/env-confgimap.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: center-config
  namespace: {{ .Values.namespace }}
  labels:
    app: {{ .Release.Name }}
data:
  ES_CLUSTER_NAME: hbjy6_dev
  ES_CLUSTER_NODES: 192.168.1.19:9500
  ETCD_ENDPOINTS: https://192.168.1.11:2379,https://192.168.1.17:2379,https://192.168.1.23:2379
  ETCD_PASSWORD: ""
  ETCD_SSL_KEY: ""
  ETCD_SSL_KEY_FILE: /mnt/mfs/private/etcd/client-key.pem
  ETCD_SSL_KEYCERT: ""
  ETCD_SSL_KEYCERT_FILE: /mnt/mfs/private/etcd/client.pem
  ETCD_SSL_TRUSTCERT: ""
  ETCD_SSL_TRUSTCERT_FILE: /mnt/mfs/private/etcd/ca.pem
  ETCD_USER: ""
  MONGODB_PASSWORD: xxxx
  MONGODB_REPLICA_SET: 192.168.1.21:37017,192.168.1.15:57017,192.168.1.16:57017
  MONGODB_USER: ROOT
  MYSQL_MASTER_PASSWORD: "xxxxx"
  MYSQL_MASTER_URL: 192.168.1.20:3306
  MYSQL_MASTER_USER: root
  MYSQL_PROXYSQL_PASSWORD: "xxxxx"
  MYSQL_PROXYSQL_URL: 192.168.1.20:1234
  MYSQL_PROXYSQL_USER: root
  REDIS_MASTER_NAME: sigma-server1
  REDIS_PASSWORD: "xxxxx"
  REDIS_SENTINEL1_HOST: 192.168.1.20
  REDIS_SENTINEL1_PORT: "26379"
  REDIS_SENTINEL2_HOST: 192.168.1.21
  REDIS_SENTINEL2_PORT: "26379"
  REDIS_SENTINEL3_HOST: 192.168.1.22
  REDIS_SENTINEL3_PORT: "26379"
  ROCKETMQ_NAMESERVER: 192.168.1.20:9876
  ZK_BUSINESS_ADDRESS: 192.168.1.20:2181,192.168.1.21:2181,192.168.1.22:2181
  ZK_REGISTRY_ADDRESS: 192.168.1.20:2181,192.168.1.21:2181,192.168.1.22:2181

# cat charts/namespace/templates/secret.yaml 
apiVersion: v1
kind: Secret
metadata:
  name: harborsecret
  namespace: {{ .Values.namespace }}
type: kubernetes.io/dockerconfigjson
data:
  .dockerconfigjson:eyJhdXRocyI6eyJoYXJib3IuNTlpZWR1LmNvbSI6eyJ1c2VybmFtZSI6ImFkbWluIiwicGFzc3dvcmQiOiJIYXJib3IxMjM0NSIsImF1dGgiOiJZV1J0YVc0NlNHRnlZbTl5TVRJek5EVT0ifX19

# cat charts/namespace/templates/mfsdata-pv-pvc.yaml 
apiVersion: v1
kind: PersistentVolume
metadata:
  name: mfsdata-{{ .Values.namespace }}
spec:
  capacity:
    storage: 150Gi 
  accessModes:
  - ReadWriteMany 
  nfs: 
    path: /mnt/mfs
    server: 192.168.1.20
  persistentVolumeReclaimPolicy: Retain
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: mfsdata-{{ .Values.namespace }}
  namespace: {{ .Values.namespace }}
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 150Gi

# cat charts/namespace/templates/clusterrole.yaml 
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: {{ .Release.Name }}-{{ .Values.namespace }}-role
  labels:
    app: {{ .Release.Name }}
rules:
- apiGroups: [""]
  resources: ["*"]
  verbs: ["get","watch","list" ]
- apiGroups: ["storage.k8s.io"]
  resources: ["*"]
  verbs: ["get","watch","list" ]
- apiGroups: ["rbac.authorization.k8s.io"]
  resources: ["*"]
  verbs: ["get","watch","list" ]
- apiGroups: ["batch"]
  resources: ["*"]
  verbs: ["get","watch","list" ]
- apiGroups: ["apps"]
  resources: ["*"]
  verbs: ["get","watch","list" ]
- apiGroups: ["extensions"]
  resources: ["*"]
  verbs: ["get","watch","list" ]

# cat charts/namespace/templates/clusterrolebinding.yaml 
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: {{ .Release.Name }}-{{ .Values.namespace }}-binding
  labels:
    app: {{ .Release.Name }}
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: {{ .Release.Name }}-{{ .Values.namespace }}-role
subjects:
- kind: ServiceAccount
  name: default
  namespace: {{ .Values.namespace }}

2、工作负载类

# cd basic
# helm create tomcat
# rm -rf charts/namespace/tomcat/*

# cat charts/tomcat/values.yaml   
# Default values for tomcat.
# This is a YAML-formatted file.
# Declare variables to be passed into your templates.

replicaCount: 1
version: v1
mfsdata: mfsdata
env:
  -server -Xms1024M -Xmx1024M -XX:MaxMetaspaceSize=320m -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=/home/tomcat/jvmdump/
  -Duser.timezone=Asia/Shanghai
  -Drocketmq.client.logRoot=/home/tomcat/logs/rocketmqlog 

image: repository: harbor.59iedu.com
pullPolicy: Always

service:
  type: ClusterIP
  port: 8080
  dubboport: 20880

ingress:
  enabled: false
  annotations: 
    nginx.ingress.kubernetes.io/rewrite-target: /
  path: /
  hosts:
    - www.test1.com
    - www.test2.com

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: 200m
    memory: 0.2Gi
   requests:
    cpu: 100m
    memory: 0.1Gi

nodeSelector: {}

tolerations:
        - key: node.kubernetes.io/not-ready
          operator: Exists
          effect: NoExecute
          tolerationSeconds: 300
        - key: node.kubernetes.io/unreachable
          operator: Exists
          effect: NoExecute
          tolerationSeconds: 300

affinity: 
       schedulerName: default-scheduler

# cat charts/tomcat/templates/deployment.yaml 
{{- $releaseName := .Release.Name -}}
apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: {{ .Release.Name }}
  namespace: {{ .Values.namespace }}
  labels:
    app: {{ .Values.namespace }}
    version: {{ .Values.version }}
spec:
  replicas: {{ .Values.replicaCount }}
  selector:
    matchLabels:
      app: {{ .Release.Name  }}
      version: {{ .Values.version }}
  template:
    metadata:
      labels:
        app: {{ .Release.Name }}
        version: {{ .Values.version }}
    strategy:
     type: RollingUpdate
     rollingUpdate:
       maxUnavailable: 25%
       maxSurge: 25%
    revisionHistoryLimit: 10
    progressDeadlineSeconds: 600
    spec:
      volumes:
        - name: hb-lan-server-xml
          configMap:
           name: hb-lan-server-xml
           items:
             - key: server.xml
               path: server.xml

        - name: vol-localtime
          hostPath:
            path: /etc/localtime
            type: ''
        - name: mfsdata
          persistentVolumeClaim:
            claimName: {{ .Values.mfsdata }}
        - name: pp-agent
          emptyDir: {}

      imagePullSecrets:
       - name: harborsecret

      initContainers:
        - name: init-pinpoint
          image: 'harbor.59iedu.com/fjhb/pp_agent:latest'
          command:
            - sh
            - '-c'
            - cp -rp /var/lib/pp_agent/* /var/init/pinpoint
          resources: {}
          volumeMounts:
            - name: pp-agent
              mountPath: /var/init/pinpoint
          terminationMessagePath: /dev/termination-log
          terminationMessagePolicy: File
          imagePullPolicy: Always

      containers:
        - name: {{ .Release.Name }}
          image: {{ .Values.image }}
          imagePullPolicy: {{ .Values.pullPolicy }}
          terminationGracePeriodSeconds: 30
          dnsPolicy: ClusterFirst
          securityContext: {}
          lifecycle:
           preStop:
            exec:
             command: ["/bin/bash", "-c", "PID=`pidof java` && kill -SIGTERM $PID && while ps -p $PID > /dev/null; do sleep 1; done;"]

          envFrom:
          - configMapRef:
               name: center-config
          env:
            - name: POD_IP
              valueFrom:
                fieldRef:
                  fieldPath: status.podIP
            - name: CATALINA_OPTS
              value: >-
                -javaagent:/var/init/pinpoint/pinpoint-bootstrap.jar
                -Dpinpoint.agentId=${POD_IP}
                -Dpinpoint.applicationName=test1-{{ .Release.Name }}
            - name: JAVA_OPTS
              value: >- 
                {{ .Values.env }}
          ports:
            - name: http
              containerPort: {{ .Values.service.port }}
              protocol: TCP
          livenessProbe:
            tcpSocket:
              port: {{ .Values.service.port }}
            initialDelaySeconds: 60
            timeoutSeconds: 2
            periodSeconds: 10
            successThreshold: 1
            failureThreshold: 3
          readinessProbe:
            tcpSocket:
              port: {{ .Values.service.dubboport }}
            initialDelaySeconds: 120
            timeoutSeconds: 3
            periodSeconds: 10
            successThreshold: 1
            failureThreshold: 3
          volumeMounts:
            - name: hb-lan-server-xml 
              mountPath: /home/tomcat/conf/server.xml
              subPath: server.xml
            - name: vol-localtime
              readOnly: true
              mountPath: /etc/localtime
            - name: mfsdata
              mountPath: /mnt/mfs
            - name: pp-agent
              mountPath: /var/init/pinpoint
          resources:
{{ toYaml .Values.resources | indent 12 }}
    {{- with .Values.nodeSelector }}
      nodeSelector:
{{ toYaml . | indent 8 }}
    {{- end }}
    {{- with .Values.affinity }}
      affinity:
        podAntiAffinity:
          PreferredDuringSchedulingIgnoredDuringExecution:
          - labelSelector:
              matchExpressions:
              - key: app
                operator: In
                values:
                - {{ $releaseName }}
            topologyKey: "kubernetes.io/hostname"
{{ toYaml . | indent 8 }}
    {{- end }}
    {{- with .Values.tolerations }}
      tolerations:
{{ toYaml . | indent 8 }}
    {{- end }}

# cat charts/tomcat/templates/ingress.yaml 
{{- if .Values.ingress.enabled -}}
{{- $servicePort := .Values.service.port -}}
{{- $ingressPath := .Values.ingress.path -}}
{{- $releaseName := .Release.Name -}}
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: {{ .Release.Name }}
  namespace: {{ .Values.namespace }}
  labels:
    app: {{ .Release.Name }}
    version: {{ .Values.version }}
{{- with .Values.ingress.annotations }}
  annotations:
{{ toYaml . | indent 4 }}
{{- end }}
spec:
{{- if .Values.ingress.tls }}
  tls:
  {{- range .Values.ingress.tls }}
    - hosts:
      {{- range .hosts }}
        - {{ . }}
      {{- end }}
      secretName: {{ .secretName }}
  {{- end }}
{{- end }}
  rules:
  {{- range .Values.ingress.hosts }}
    - host: {{ . }}
      http:
        paths:
          - path: {{ $ingressPath }}
            backend:
              serviceName: {{ $releaseName }}
              servicePort: {{ $servicePort }}
  {{- end }}
{{- end }}

# cat charts/tomcat/templates/service.yaml 
apiVersion: v1
kind: Service
metadata:
  name: {{ .Release.Name  }}
  namespace: {{ .Values.namespace }}
  labels:
    app: {{ .Release.Name  }}
    version: {{ .Values.version }}
spec:
  type: {{ .Values.service.type }}
  ports:
    - port: {{ .Values.service.port }}
      targetPort: http
      protocol: TCP
      name: http
  selector:
    app: {{ .Release.Name  }}
    version: {{ .Values.version }}

3、运行测试

# helm install --debug --dry-run /root/basic/charts/namespace/  \
--set namespace=test3

# helm install --debug --dry-run /root/basic/charts/tomcat/   \
--name tomcat-test \
--set namespace=test3  \
--set mfsdata=mfsdata-test3 \
--set replicaCount=2 \
--set image=harbor.59iedu.com/dev/tomcat_base:v1.1-20181127 \
--set ingress.enabled=true \
--set ingress.hosts={tomcat.59iedu.com} \
--set resources.limits.cpu=2000m \
--set resources.limits.memory=2Gi \
--set resources.requests.cpu=500m \
--set resources.requests.memory=1Gi \
--set service.dubboport=8080

4、创建release

# helm install  /root/basic/charts/namespace/ --set namespace=test3

# helm install  /root/basic/charts/tomcat/   \
--name tomcat-test \
--set namespace=test3  \
--set mfsdata=mfsdata-test3 \
--set replicaCount=2 \
--set image=harbor.59iedu.com/dev/tomcat_base:v1.1-20181127 \
--set ingress.enabled=true \
--set ingress.hosts={tomcat.59iedu.com} \
--set resources.limits.cpu=2000m \
--set resources.limits.memory=2Gi \
--set resources.requests.cpu=500m \
--set resources.requests.memory=1Gi \
--set service.dubboport=8080

四、更新与回滚

# helm upgrade --install tomcat-test \
--values /root/basic/charts/tomcat/values.yaml   \
--set namespace=test3  \
--set mfsdata=mfsdata-test3 \
--set replicaCount=1 \
--set image=harbor.59iedu.com/dev/tomcat_base:v1.1-20181127 \
--set ingress.enabled=true \
--set ingress.hosts={tomcat1.59iedu.com} \
--set resources.limits.cpu=200m \
--set resources.limits.memory=1Gi \
--set resources.requests.cpu=100m \
--set resources.requests.memory=0.5Gi \
--set service.dubboport=8080 \
/root/basic/charts/tomcat

万一更新失败，可选择回滚

# helm rollback tomcat-test 1  
# helm history tomcat-test 
# helm get --revision 1 tomcat-test