以下是一个k8s上部署mongodb的简单例子 创建了一个mongodb的namespace, 创建了SA, clusterrole,名为mongo的服务, 名为mongo的3个有状态副本

mongo.yaml

# mongo.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: mongodb
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: mongo
  namespace: mongodb
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: mongo
subjects:
  - kind: ServiceAccount
    name: mongo
    namespace: mongodb
roleRef:
  kind: ClusterRole
  name: cluster-admin
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: v1
kind: Service
metadata:
 name: mongo
 namespace: mongodb
 labels:
   name: mongo
spec:
 ports:
 - port: 27017
   targetPort: 27017
 clusterIP: None
 selector:
   role: mongo
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mongo
  namespace: mongodb
spec:
  serviceName: mongo
  replicas: 3
  selector:
    matchLabels:
      role: mongo
      environment: staging
  template:
    metadata:
      labels:
        role: mongo
        environment: staging
        replicaset: MainRepSet
    spec:
      affinity:
        podAntiAffinity:  # 添加 Pod 反亲和性，将副本打散在不同的节点
          preferredDuringSchedulingIgnoredDuringExecution:  # 软策略
          - weight: 100
            podAffinityTerm:
              labelSelector:
                matchExpressions:
                - key: replicaset
                  operator: In
                  values:
                  - MainRepSet
              topologyKey: kubernetes.io/hostname
      terminationGracePeriodSeconds: 10
      serviceAccountName: mongo
      containers:
        - name: mongo
          image: mongo:4.4
          command:
            - mongod
            - "--wiredTigerCacheSizeGB"
            - "0.25"
            - "--bind_ip"
            - "0.0.0.0"
            - "--replSet"
            - MainRepSet
            #- "--smallfiles"
            #- "--noprealloc"
          ports:
            - containerPort: 27017
          volumeMounts:
            - name: mongo-data
              mountPath: /data/db
          resources:
            requests:
              cpu: 1
              memory: 2Gi
        - name: mongo-sidecar
          image: cvallance/mongo-k8s-sidecar
          env:
            - name: MONGO_SIDECAR_POD_LABELS
              value: "role=mongo,environment=staging"
            - name: KUBE_NAMESPACE
              value: "mongo"
            - name: KUBERNETES_MONGO_SERVICE_NAME
              value: "mongo"
  volumeClaimTemplates:
  - metadata:
      name: mongo-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: openebs-hostpath # 提供一个可用的 Storageclass
      resources:
        requests:
          storage: 30Gi

3个pod启动以后, 进入其中一个pod,然后执行集群创建命令

kubectl -n mongodb exec -it mongo-0 -- mongo
rs.status() #查看集群状态
#创建集群
config = { _id:"MainRepSet", members:[
                     {_id:0,host:"mongo-0.mongo.mongodb.svc.cluster.local:27017",priority:90},
                     {_id:1,host:"mongo-1.mongo.mongodb.svc.cluster.local:27017",priority:80},
                     {_id:2,host:"mongo-2.mongo.mongodb.svc.cluster.local:27017",priority:70}
    ]
}

rs.initiate(config);
rs.status() #查看集群状态

优化

set -o errexit
set -o pipefail
set -o nounset
echo 'never' > /sys/kernel/mm/transparent_hugepage/enabled
echo 'never' > /sys/kernel/mm/transparent_hugepage/defrag

设置或修改密码

#查看数据库
show dbs

#切换admin库
use admin

#创建管理员账户,用于管理账号，不能进行关闭数据库
db.createUser({ user: "admin", pwd: "password", roles: [{ role: "userAdminAnyDatabase", db: "admin" }] })

#创建root,超级管理员root,可关闭数据库
db.createUser({user: "root",pwd: "password", roles: [ { role: "root", db: "admin" } ]})

#创建用户自己的数据库的管理角色,一定要切换到所在数据库上去创建用户，不然创建的用户还是属于admin。
use yourdatabase
db.createUser({user: "user",pwd: "password",roles: [ { role: "dbOwner", db: "yourdatabase" } ]})

#查看用户
show users

#删库用户
use admin
db.auth("admin","password")

#删除单个用户
db.system.users.remove({user:"XXXXXX"})
#删除所有用户
db.system.users.remove({}

#连接字符串
mongodb://username:password@ip:port/database 
mongodb://username:password@ip0:port,ip1:port,ip2:port/database?replicaSet=MainRepSet

springboot 在nacos中的配置

    mongodb:
      uri: mongodb://mongo-0.mongo.mongodb.svc.cluster.local:27017,mongo-1.mongo.mongodb.svc.cluster.local:27017,mongo-2.mongo.mongodb.svc.cluster.local:27017/database?replicaSet=MainRepSet
      auto-index-creation: true # 默认为false，即不会自动创建索引