AKS集群中MongoDB持续崩溃报错ECONNREFUSED求助

刚接触K8s，在Azure Kubernetes Service（AKS）上部署依赖MongoDB的微服务，AKS集群已创建，微服务运行正常，但MongoDB部署持续崩溃。日志报错：MongoNetworkError: connect ECONNREFUSED 127.0.0.1:27017

相关配置文件 #

mongo.yml #

kind: Deployment
metadata:
  name: mongo-deployment
  labels:
    app: mongodb
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mongodb
  template:
    metadata:
      labels:
        app: mongodb
    spec:
      containers:
      - name: mongodb
        image: mongo
        ports:
          - containerPort: 27017
        resources:
          requests:
            memory: "64Mi"
            cpu: "250m"
          limits:
            memory: "128Mi"
            cpu: "500m"
        env:
          - name: MONGO_INITDB_ROOT_USERNAME
            valueFrom: 
              secretKeyRef:
                name: mongo-secret
                key: mongo-root-username
          - name: MONGO_INITDB_ROOT_PASSWORD
            valueFrom: 
              secretKeyRef:
                name: mongo-secret
                key: mongo-root-password
---
apiVersion: v1
kind: Service
metadata:
  name: mongo-service
spec:
  selector:
    app: mongodb
  ports:
  - protocol: TCP
    port: 27017
    targetPort: 27017

mongo-configmap.yml #

apiVersion: v1
kind: ConfigMap
metadata:
  name: mongo-configmap
data:
  connection_string: mongodb://username:password@mongo-service:27017

mongo-secret.yml #

kind: Secret
metadata:
  name: mongo-secret
type: Opaque
data:
  mongo-root-username: dXNlcm5hbWU=
  mongo-root-password: cGFzc3dvcmQ=

kubectl describe pod 输出 #

Namespace:        default
Priority:         0
Service Account:  default
Node:             aks-nodepool1-85690495-vmss000000/10.224.0.4
Start Time:       Tue, 25 Apr 2023 11:34:41 +0300
Labels:           app=mongodb
                  pod-template-hash=5d456c788f
Annotations:      <none>
Status:           Running
IP:               10.244.0.37
IPs:
  IP:           10.244.0.37
Controlled By:  ReplicaSet/mongo-deployment-5d456c788f
Containers:
  mongodb:
    Container ID:   containerd://6862b0a5291f7a4a6d1a7f81ba5b5fe2286f04a7d8aa7817cad2b48142190352
    Image:          mongo
    Image ID:       docker.io/library/mongo@sha256:9c8a0a019671ed7d402768d4df6dddcc898828e21e9f7b90a34b55fe8ca676ac
    Port:           27017/TCP
    Host Port:      0/TCP
    State:          Waiting
      Reason:       CrashLoopBackOff
    Last State:     Terminated
      Reason:       OOMKilled
      Exit Code:    1
      Started:      Tue, 25 Apr 2023 12:03:17 +0300
      Finished:     Tue, 25 Apr 2023 12:03:21 +0300
    Ready:          False
    Restart Count:  10
    Limits:
      cpu:     500m
      memory:  128Mi
    Requests:
      cpu:     250m
      memory:  64Mi
    Environment:
      MONGO_INITDB_ROOT_USERNAME:  <set to the key 'mongo-root-username' in secret 'mongo-secret'>  Optional: false
      MONGO_INITDB_ROOT_PASSWORD:  <set to the key 'mongo-root-password' in secret 'mongo-secret'>  Optional: false
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-l6l84 (ro)
Conditions:
  Type              Status
  Initialized       True
  Ready             False
  ContainersReady   False
  PodScheduled      True
Volumes:
  kube-api-access-l6l84:
    Type:                    Projected (a volume that contains injected data from multiple sources)
    TokenExpirationSeconds:  3607
    ConfigMapName:           kube-root-ca.crt
    ConfigMapOptional:       <nil>
    DownwardAPI:             true
QoS Class:                   Burstable
Node-Selectors:              <none>
Tolerations:                 node.kubernetes.io/memory-pressure:NoSchedule op=Exists
                             node.kubernetes.io/not-ready:NoExecute op=Exists for 300s
                             node.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:
  Type     Reason     Age                    From               Message
  ----     ------     ----                   ----               -------
  Normal   Scheduled  30m                    default-scheduler  Successfully assigned default/mongo-deployment-5d456c788f-587r6 to aks-nodepool1-85690495-vmss000000   
  Normal   Pulled     30m                    kubelet            Successfully pulled image "mongo" in 735.583384ms (735.618884ms including waiting)
  Normal   Pulled     30m                    kubelet            Successfully pulled image "mongo" in 788.963634ms (788.974334ms including waiting)
  Normal   Pulled     30m                    kubelet            Successfully pulled image "mongo" in 725.867064ms (725.879864ms including waiting)
  Normal   Created    29m (x4 over 30m)      kubelet            Created container mongodb
  Normal   Started    29m (x4 over 30m)      kubelet            Started container mongodb
  Normal   Pulled     29m                    kubelet            Successfully pulled image "mongo" in 783.028263ms (783.042864ms including waiting)
  Normal   Pulling    27m (x5 over 30m)      kubelet            Pulling image "mongo"
  Normal   Pulled     27m                    kubelet            Successfully pulled image "mongo" in 738.599919ms (738.611919ms including waiting)
  Warning  BackOff    5m57s (x107 over 30m)  kubelet            Back-off restarting failed container

已尝试删除并重建Pod，问题仍存在，请求解决办法。

从kubectl describe pod输出可知，MongoDB容器终止原因是OOMKilled（内存不足被系统杀死），这是核心问题，结合配置细节给出以下解决步骤：

1. 调整MongoDB内存资源限制
   默认MongoDB镜像启动所需内存超过当前配置的128Mi限制，建议提升内存配额：
   修改mongo.yml中resources部分：

   resources:
     requests:
       memory: "256Mi"
       cpu: "250m"
     limits:
       memory: "512Mi"
       cpu: "500m"
   

2. 修正微服务连接目标
   日志中的127.0.0.1:27017连接错误，说明微服务可能错误地指向了本地而非MongoDB服务。确保微服务使用ConfigMap中的mongo-service:27017作为连接地址，同时确认ConfigMap中的用户名密码与Secret一致（当前Secret值为username和password，匹配ConfigMap配置）。

3. 添加持久化存储（可选但推荐）
   当前部署未挂载持久卷，MongoDB每次重启会丢失数据，也可能因无存储目录导致启动异常。添加PersistentVolumeClaim：
   在mongo.yml的containers节点下添加volumeMounts，同时在Pod的spec下添加volumes：

   containers:
   - name: mongodb
     # 其他原有配置
     volumeMounts:
     - name: mongo-storage
       mountPath: /data/db
   volumes:
   - name: mongo-storage
     persistentVolumeClaim:
       claimName: mongo-pvc
   

   同时创建mongo-pvc.yml：

   apiVersion: v1
   kind: PersistentVolumeClaim
   metadata:
     name: mongo-pvc
   spec:
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 10Gi
   

4. 应用配置更新
   执行命令刷新部署：

   kubectl apply -f mongo.yml
   # 若添加了PVC，执行：
   kubectl apply -f mongo-pvc.yml
   

5. 验证启动状态
   查看MongoDB容器详细日志确认是否启动成功：

   kubectl logs <mongo-pod-name>
   

内容的提问来源于stack exchange，提问作者Andrei Popescu