SpringBoot 3操作MongoDB触发Error 18认证失败问题求助

问题描述 #

SpringBoot 3连接Docker部署的MongoDB时，连接阶段无异常，但执行插入/保存文档操作时触发认证失败错误，错误信息如下：

Caused by: com.mongodb.MongoCommandException: Command failed with error 18 (AuthenticationFailed): 'Authentication failed.' on server localhost:27017. The full response is {"ok": 0.0, "errmsg": "Authentication failed.", "code": 18, "codeName": "AuthenticationFailed"}
    at com.mongodb.internal.connection.ProtocolHelper.getCommandFailureException(ProtocolHelper.java:205) ~[mongodb-driver-core-4.9.1.jar:na]
    at com.mongodb.internal.connection.InternalStreamConnection.receiveCommandMessageResponse(InternalStreamConnection.java:443) ~[mongodb-driver-core-4.9.1.jar:na]
    at com.mongodb.internal.connection.InternalStreamConnection.sendAndReceive(InternalStreamConnection.java:365) ~[mongodb-driver-core-4.9.1.jar:na]
    at com.mongodb.internal.connection.CommandHelper.sendAndReceive(CommandHelper.java:102) ~[mongodb-driver-core-4.9.1.jar:na]
    at com.mongodb.internal.connection.CommandHelper.executeCommand(CommandHelper.java:49) ~[mongodb-driver-core-4.9.1.jar:na]
    at com.mongodb.internal.connection.SaslAuthenticator.sendSaslStart(SaslAuthenticator.java:224) ~[mongodb-driver-core-4.9.1.jar:na]
    at com.mongodb.internal.connection.SaslAuthenticator.getNextSaslResponse(SaslAuthenticator.java:131) ~[mongodb-driver-core-4.9.1.jar:na]
    ... 62 common frames omitted

相关配置文件：

application.yml #

server:
  port: 8400
spring:
  application:
    name: notification-service
  kafka:
    bootstrap:
      servers: https://localhost:9092
  data:
    mongodb:
      username: "root"
      password: "example"
      host: "localhost"
      port: 27017
      database: "notification"
      authentication-database: "admin"
      #uri: mongodb://root:example@127.0.0.1:27017/notification?authSource=admin (I tried uri but didnt work as it was provided solution on stackoverflow)

docker-compose.yml #

mongo:
    image: mongo
    restart: always
    environment:
      MONGO_INITDB_ROOT_USERNAME: root
      MONGO_INITDB_ROOT_PASSWORD: example
    volumes:
      - mongodb:/data
  mongo-express:
    image: mongo-express
    restart: always
    ports:
      - 8081:8081
    environment:
      ME_CONFIG_MONGODB_ADMINUSERNAME: root
      ME_CONFIG_MONGODB_ADMINPASSWORD: example
      ME_CONFIG_MONGODB_URL: mongodb://root:example@mongo:27017/
      ME_CONFIG_BASICAUTH_USERNAME: mexpress
      ME_CONFIG_BASICAUTH_PASSWORD: mexpress
volumes:
  mongodb:

解决步骤 #

1. 重置MongoDB初始化数据 #

MongoDB的MONGO_INITDB_*环境变量仅在容器第一次创建并挂载空数据卷时生效，如果之前容器已经启动过，可能存在初始化异常。执行以下操作重置：

# 停止容器并删除数据卷
docker-compose down -v
# 重新启动Mongo容器
docker-compose up -d mongo

等待容器启动后，进入容器验证root用户是否存在：

docker exec -it $(docker ps -q -f name=mongo) mongosh -u root -p example --authenticationDatabase admin
use admin
db.getUser("root")

如果返回用户信息，说明初始化正常；如果返回null，查看容器日志排查初始化问题：

docker logs $(docker ps -q -f name=mongo)

2. 修正SpringBoot MongoDB URI配置 #

直接使用URI配置避免分散参数冲突，同时指定认证机制，修改application.yml：

spring:
  data:
    mongodb:
      uri: mongodb://root:example@localhost:27017/notification?authSource=admin&authMechanism=SCRAM-SHA-1

SpringBoot 3搭配的Mongo驱动默认可能使用SCRAM-SHA-256，但旧版本Mongo容器初始化的用户可能仅支持SCRAM-SHA-1，显式指定可避免兼容性问题。

3. 验证驱动版本兼容性 #

SpringBoot 3.x默认搭配的MongoDB驱动版本为4.10+，确保你的依赖没有手动指定低版本：

Maven

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-mongodb</artifactId>
</dependency>

Gradle

implementation 'org.springframework.boot:spring-boot-starter-data-mongodb'

手动指定驱动版本时，必须保证和SpringBoot 3兼容。

4. 本地直连测试 #

先用Mongo Shell直接连接测试，排除网络或认证信息问题：

mongosh mongodb://root:example@localhost:27017/notification?authSource=admin

如果连接失败，先解决网络或认证信息问题，再调试SpringBoot应用。

5. 创建数据库专用用户（推荐） #

避免使用root超级管理员操作业务数据库，为notification数据库创建专用读写用户：
进入Mongo容器Shell：

docker exec -it $(docker ps -q -f name=mongo) mongosh -u root -p example --authenticationDatabase admin
use notification
db.createUser({
  user: "notification_user",
  pwd: "notification_pwd",
  roles: [ { role: "readWrite", db: "notification" } ]
})

修改SpringBoot配置为专用用户：

spring:
  data:
    mongodb:
      username: notification_user
      password: notification_pwd
      host: localhost
      port: 27017
      database: notification
      authentication-database: notification

内容的提问来源于stack exchange，提问作者zeyad ahmed