在Kubernetes中运行复制的MongoDB 4.2 :未接收复制配置

Question

我正在AWS上运行一个Kubernetes集群，需要配置一个复制的MongoDB 4.2数据库。我使用StatefulSets是为了让其他Pods (例如REST Pod)能够轻松地连接到mongo实例(例如dsn："mongodb://mongo-0.mongo，mongo-1 mongo，mongo-2 mongo:27017/app“)。

mongo configmap.yaml(提供一个shell脚本，用于在mongo容器创建时执行复制初始化)：

apiVersion: v1
kind: ConfigMap
metadata:
  name: mongo-init
data:
  init.sh: |
    #!/bin/bash
    # wait for the readiness health check to pass 
    until ping -c 1 ${HOSTNAME}.mongo; do
      echo "waiting for DNS (${HOSTNAME}.mongo)..."
      sleep 2
    done
    until /usr/bin/mongo --eval 'printjson(db.serverStatus())'; do
      echo "connecting to local mongo..."
      sleep 2
    done
    echo "connected to local."
    HOST=mongo-0.mongo:27017
    until /usr/bin/mongo --host=${HOST} --eval 'printjson(db.serverStatus())'; do
      echo "connecting to remote mongo..."
      sleep 2
    done
    echo "connected to remote."
    if [[ "${HOSTNAME}" != 'mongo-0' ]]; then
      until /usr/bin/mongo --host=${HOST} --eval="printjson(rs.status())" \
            | grep -v "no replset config has been received"; do
        echo "waiting for replication set initialization"
        sleep 2
      done
      echo "adding self to mongo-0"
      /usr/bin/mongo --host=${HOST} --eval="printjson(rs.add('${HOSTNAME}.mongo'))"
    fi
    if [[ "${HOSTNAME}" == 'mongo-0' ]]; then
      echo "initializing replica set"
      /usr/bin/mongo --eval="printjson(rs.initiate(\
          {'_id': 'rs0', 'members': [{'_id': 0, \
           'host': 'mongo-0.mongo:27017'}]}))"
    fi
    echo "initialized"
    while true; do
      sleep 3600
    done

蒙古-服务公司：

apiVersion: v1
kind: Service
metadata:
  name: mongo
  labels:
    app: mongo
spec:
  clusterIP: None
  ports:
  - port: 27017
  selector:
    app: mongo

other (两个容器在一个Pod中，一个用于实际DB，另一个用于复制的初始化)：

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: mongo
  labels:
    app: mongo
spec:
  selector:
    matchLabels:
      app: mongo
  serviceName: "mongo"
  replicas: 3
  template:
    metadata:
      labels:
        app: mongo
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: mongodb
        image: mongo:4.2
        command:
        - mongod
        args:
        - --replSet
        - rs0
        - "--bind_ip_all"
        ports:
        - containerPort: 27017
          name: web
        volumeMounts:
        - name: database
          mountPath: /data/db
        livenessProbe:
          exec:
            command:
            - /usr/bin/mongo
            - --eval
            - db.serverStatus()
          initialDelaySeconds: 10
          timeoutSeconds: 10
      - name: init-mongo
        image: mongo:4.2
        command:
        - bash
        - /config/init.sh
        volumeMounts:
        - name: config
          mountPath: /config
      volumes:
      - name: config
        configMap:
          name: "mongo-init"
  volumeClaimTemplates:
  - metadata:
      name: database
      annotations:
        volume.beta.kubernetes.io/storage-class: mongodb-storage
    spec:
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 5Gi

应用这些配置后，3个芒果荚开始运行( mongo -0，mongo-1，mongo-2).然而，其他的荚不能连接到这些芒果荚。进一步研究mongo-0pods(应该是主要实例)可以发现复制不起作用。

kubectl exec -it mongo-0 - /bin/bash

然后运行' mongo‘启动mongo，并在mongo中输入'rs.status()’，得到以下输出：

{
    "info" : "run rs.initiate(...) if not yet done for the set",
    "ok" : 0,
    "errmsg" : "no replset config has been received",
    "code" : 94,
    "codeName" : "NotYetInitialized"
}

Answer 1

显然，mongo-4.x映像没有安装'ping‘，因此脚本的其余部分没有执行。在mongo-configmap.yaml中将这两行代码添加到脚本中可以解决以下问题：

apt-get update
apt-get install iputils-ping --yes

Answer 2

在开始运行所有豆荚之后，然后按下以下命令

 kubectl exec -it mongo-0 -- /bin/bash

(这里的mongo-0是荚名)

现在开始芒果壳，

mongo

现在检查吊舱是否启动

rs.status()

如果不是这样，那么通过一个接一个地按下这些命令来启动并使其成为主命令。

rs.initiate()

var cfg = rs.conf()

cfg.members[0].host=”mongo-0.mongo:27017”

(这里是mongo-0是荚名，mongo是序列化名。)

现在重新配置主节点

rs.reconfig(cfg)

将所有从节点添加到主节点

rs.add(“mongo-1.mongo:27017”)

rs.add(“mongo-2.mongo:27017”)

(这是mongo-1，mongo-2是荚名，mongo是序列名。)

现在检查状态

rs.status()

现在退出主shell并转到次要(从)节点

exit

exit

kubectl exec -it mongo-1 -- /bin/bash

mongo

rs.secondaryOk()

检查状态和出口

rs.status()
exit
exit

现在，对其他辅助(从)节点执行同样的操作。