I have created a docker environment which runs

1. mongo – starts mongodb
2. mongoimport – puts in some dummy data
3. ordersearchservice – spring-boot microservice app
4. productinfoservice – spring-boot microservice app
5. userinfoservice – spring-boot microservice app

userinfoservice is the only one which needs to connect to mongodb as of now.
It is supposed to fetch user-details from mongodb document.
Everything is working fine if I run it outside docker container, but if I start the container, mongodb connection is not working correctly.
There are two errors.

1. Error during userinfoservice startup

Exception in monitor thread while connecting to server localhost:27017
userinfoservice-1     |
userinfoservice-1     | com.mongodb.MongoSocketOpenException: Exception opening socket
userinfoservice-1     |         at 

2. Error while hitting the controller from postman (or even directly from browser)

userinfoservice-1     | org.springframework.dao.DataAccessResourceFailureException: Timed out after 30000 ms while waiting for a server that matches ReadPreferenceServerSelector{readPreference=primary}. Client view of cluster state is {type=UNKNOWN, servers=[{address=localhost:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketOpenException: Exception opening socket}, caused by {io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: localhost/[0:0:0:0:0:0:0:1]:27017}, caused by {java.net.ConnectException: Connection refused}}]
userinfoservice-1     |         at org.springframework.data.mongodb.core.MongoExceptionTranslator.translateExceptionIfPossible(MongoExceptionTranslator.java:88) ~[spring-data-mongodb-4.2.5.jar!/:4.2.5]

Here are the files I am using

1. docker-compose.yml

version: "3"

services:
  mongo:
    image: mongo
    container_name: mongodb
    ports:
      - "27017:27017"
    environment:
      MONGO_INITDB_ROOT_USERNAME: root
      MONGO_INITDB_ROOT_PASSWORD: pwd
      MONGO_INITDB_DATABASE: admin

  mongoimport:
    image: mongo
    volumes:
      - ./mongo/data/users.json:/src/data/users.json
    command: mongoimport --host mongo --username root --password pwd --db admin --collection users --file /src/data/users.json --jsonArray
    depends_on:
      - mongo

  ordersearchservice:
    build:
      context: ./order-search-service
      dockerfile: Dockerfile
    image: order-search-service
    ports:
      - "8081:8081"
    depends_on:
      - mongoimport
    environment:
      SPRING_DATA_MONGODB_URI: mongodb://root:pwd@localhost:27017/admin

  productinfoservice:
    build:
      context: ./product-info-service
      dockerfile: Dockerfile
    image: product-info-service
    ports:
      - "8082:8082"
    depends_on:
      - ordersearchservice
    environment:
      SPRING_DATA_MONGODB_URI: mongodb://root:pwd@localhost:27017/admin

  userinfoservice:
    build:
      context: ./user-info-service
      dockerfile: Dockerfile
    image: user-info-service
    ports:
      - "8083:8083"
    depends_on:
      - productinfoservice
    environment:
      SPRING_DATA_MONGODB_URI: mongodb://root:pwd@localhost:27017/admin

2. userinfoservice/pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.2.5</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.shaan</groupId>
    <artifactId>user-info-service</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>user-info-service</name>
    <description>User Info service</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-webflux</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongodb-driver-reactivestreams</artifactId>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>io.projectreactor</groupId>
            <artifactId>reactor-core</artifactId>
        </dependency>
        <dependency>
            <groupId>io.projectreactor</groupId>
            <artifactId>reactor-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb-reactive</artifactId>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

3. userinfoservice/Dockerfile

FROM maven:3.8.4-openjdk-17 AS build
WORKDIR /app
COPY pom.xml .
RUN mvn dependency:go-offline -B
COPY src ./src
RUN mvn package -DskipTests

FROM openjdk:17-oracle
WORKDIR /app
COPY --from=build /app/target/user-info-service-0.0.1-SNAPSHOT.jar .
ENTRYPOINT  java -jar user-info-service-0.0.1-SNAPSHOT.jar

4. userinfoservice/src/main/resources/application.properties

spring.application.name=user-info-service
spring.data.mongodb.uri=mongodb://root:pwd@localhost:27017/admin

searchOrderByPhoneUrl=http://localhost:8081/orderSearchService/order/phone
searchProductByProductCode=http://localhost:8082/productInfoService/product/names

server.port=8083

I have already tried below things:

1. I thought mongodb has not started already when userinfoservice is starting, so I made it to depend on mongodb.
2. I double checked for database connection issue, but docker is starting up mongodb perfectly fine
3. I checked database reactive driver in pom.xml and that also looks to be in place (Not needed as application is working fine outside docker)
4. I checked firewall. There is nothing.

But still I am not able to fetch data when the service is running in docker.
Please let me know if I am missing anything. Thanks for help.