在Minikube中配置LoadBalancer以直接访问SQL Server

问题背景 #

我在本地使用Minikube部署SQL Server，已配置ClusterIP和LoadBalancer Service，但无法从外部建立连接。尝试了多种地址组合均失败，错误提示Name or service not known，推测是网络层面的问题。

配置文件 #

mssql-depl.yaml #

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mssql-depl
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mssql
  template:
    metadata:
      labels:
        app: mssql
    spec:
      containers:
        - name: mssql
          image: mcr.microsoft.com/mssql/server:2017-latest
          ports:
            - containerPort: 1433
          env:
          - name: MSSQL_PID
            value: "Express"
          - name: ACCEPT_EULA
            value: "Y"
          - name: SA_PASSWORD
            valueFrom:
              secretKeyRef:
                name: mssql
                key: SA_PASSWORD
          volumeMounts:
          - mountPath: /var/opt/mssql/data
            name: mssqldb
      volumes:
      - name: mssqldb
        persistentVolumeClaim:
          claimName: mssql-claim
---
apiVersion: v1
kind: Service
metadata:
  name: mssql-clusterip-srv
spec:
  type: ClusterIP
  selector:
    app: mssql
  ports:
    - name: mssql
      protocol: TCP
      port: 1433
      targetPort: 1433
---
apiVersion: v1
kind: Service
metadata:
  name: mssql-loadbalancer
spec:
  type: LoadBalancer
  selector:
    app: mssql
  ports:
    - name: mssql
      protocol: TCP
      port: 1433
      targetPort: 1433

local-pvc.yaml #

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: mssql-claim
spec:
  resources:
    requests:
      storage: 200Mi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany

执行结果 #

执行kubectl apply -f msql-depl.yaml后，运行kubectl get services得到以下输出：

NAME                      TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)          AGE
commands-clusterip-srv    ClusterIP      10.96.28.141     <none>        80/TCP           20h
kubernetes                ClusterIP      10.96.0.1        <none>        443/TCP          2d21h
mssql-clusterip-srv       ClusterIP      10.105.217.207   <none>        1433/TCP         29s
mssql-loadbalancer        LoadBalancer   10.107.63.199    <pending>     1433:31681/TCP   28s
platforms-clusterip-srv   ClusterIP      10.98.35.159     <none>        80/TCP           44h
platformservice-srv       NodePort       10.104.221.184   <none>        80:30201/TCP     2d21h

运行minikube ip返回192.168.59.100，尝试过以下地址均连接失败：

• 192.168.59.100:1433
• localhost:1433
• localhost:31681
• 192.168.59.100:31681
• 10.107.63.199:1433
• 10.107.63.199:31681

错误详情 #

Microsoft.Data.SqlClient.SqlException (0x80131904): 建立与 SQL Server 的连接时出现与网络相关的或特定于实例的错误。找不到服务器或无法访问服务器。请验证实例名称是否正确，并且 SQL Server 配置为允许远程连接。 (provider: TCP Provider, error: 35 - 捕获到内部异常)
 ---> System.Net.Sockets.SocketException (00000005, 0xFFFDFFFF): Name or service not known
   at System.Net.Dns.GetHostEntryOrAddressesCore(String hostName, Boolean justAddresses, AddressFamily addressFamily, Int64 startingTimestamp)
   at System.Net.Dns.GetHostAddresses(String hostNameOrAddress, AddressFamily family)
   at Microsoft.Data.SqlClient.SNI.SNICommon.GetDnsIpAddresses(String serverName)
   at Microsoft.Data.SqlClient.SNI.SNITCPHandle.Connect(String serverName, Int32 port, TimeSpan timeout, Boolean isInfiniteTimeout, SqlConnectionIPAddressPreference ipPreference, String cachedFQDN, SQLDNSInfo& pendingDNSInfo)
   at Microsoft.Data.SqlClient.SNI.SNITCPHandle..ctor(String serverName, Int32 port, Int64 timerExpire, Boolean parallel, SqlConnectionIPAddressPreference ipPreference, String cachedFQDN, SQLDNSInfo& pendingDNSInfo, Boolean tlsFirst, String hostNameInCertificate, String serverCertificateFilename)
   at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
   at Microsoft.Data.SqlClient.TdsParser.Connect(ServerInfo serverInfo, SqlInternalConnectionTds connHandler, Boolean ignoreSniOpenTimeout, Int64 timerExpire, SqlConnectionString connectionOptions, Boolean withFailover)
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
   at Microsoft.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userOptions, SessionData reconnectSessionData, Boolean applyTransientFaultHandling, String accessToken, DbConnectionPool pool)
   at Microsoft.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
   at Microsoft.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
   at Microsoft.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at Microsoft.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
   at Microsoft.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
   at Microsoft.Data.ProviderBase.DbConnectionPool.WaitForPendingOpen()
--- End of stack trace from previous location ---
   at Microsoft.Data.SqlClient.SqlRetryLogicProvider.ExecuteAsync(Object sender, Func`1 function, CancellationToken cancellationToken)
   at Microsoft.Data.SqlClient.SqlRetryLogicProvider.ExecuteAsync(Object sender, Func`1 function, CancellationToken cancellationToken)
   at Microsoft.SqlTools.ServiceLayer.Connection.ReliableConnection.ReliableSqlConnection.<>c__DisplayClass30_0.<<OpenAsync>b__0>d.MoveNext() in /_/src/Microsoft.SqlTools.ManagedBatchParser/ReliableConnection/ReliableSqlConnection.cs:line 319
--- End of stack trace from previous location ---
   at Microsoft.SqlTools.ServiceLayer.Connection.ConnectionService.TryOpenConnection(ConnectionInfo connectionInfo, ConnectParams connectionParams) in /_/src/Microsoft.SqlTools.ServiceLayer/Connection/ConnectionService.cs:line 712
ClientConnectionId:00000000-0000-0000-0000-000000000000

排查步骤与解决方案 #

1. 正确暴露Minikube LoadBalancer服务 #

Minikube没有原生LoadBalancer支持，需通过minikube tunnel分配外部IP：

• 打开新终端执行minikube tunnel并保持运行
• 重新执行kubectl get services，此时mssql-loadbalancer会获得有效EXTERNAL-IP，使用该IP+1433端口连接

2. 验证Pod运行状态 #

执行kubectl get pods确认mssql-depl-xxx状态为Running：

• 若Pod未启动，执行kubectl logs mssql-depl-xxx查看日志，排查PVC绑定失败、SA密码不符合复杂度要求等问题

3. 检查容器内SQL Server状态 #

进入容器验证服务运行情况：

kubectl exec -it mssql-depl-xxx -- /bin/bash
# 查看版本
/opt/mssql/bin/sqlservr --version
# 检查进程状态
ps aux | grep sqlservr

4. 测试集群内部连接 #

临时启动测试Pod验证集群内服务可用性：

kubectl run -it --rm --image=mcr.microsoft.com/mssql-tools:latest sqlcmd

进入容器后执行连接命令：

sqlcmd -S mssql-clusterip-srv,1433 -U SA -P "<你的SA密码>"

若能连接，说明集群内服务正常，问题出在外部网络暴露环节

5. 检查端口与防火墙 #

• 用telnet 192.168.59.100 31681或nc -zv 192.168.59.100 31681测试NodePort端口是否可达
• 确认本地防火墙未阻止31681或1433端口

内容的提问来源于stack exchange，提问作者Ian Tunbridge