MongoDB Cannot run tests when building Docker image - Server selection error: server selection timeout

I'm running a mongo image in a container with this config:

version: '3'
services:
  mongodb:
    image: mongo
    ports:
      - '27017:27017'
    environment:
      - MONGO_INITDB_ROOT_USERNAME=user
      - MONGO_INITDB_ROOT_PASSWORD=password
      - MONGO_INITDB_DATABASE=microservices
    volumes:
      - ./docker-entrypoint-initdb.d/mongo-init.js:/docker-entrypoint-initdb.d/mongo-init.js:ro

And I have started to build microservices with golang and I want to start dockerizing those as well to speed up the development process. However when I try to run this Dockerfile below it panics at the run test command with the error:

database url:  mongodb://user:password@127.0.0.1:27017/microservices
server selection error: server selection timeout, current topology: { Type: Unknown, Servers: [{ Addr: 127.0.0.1:27017, Type: Unknown, Last error: connection() error occurred during connection handshake: dial tcp 127.0.0.1:27017: connect: connection refused }, ] }

panic: server selection error: server selection timeout, current topology: { Type: Unknown, Servers: [{ Addr: 127.0.0.1:27017, Type: Unknown, Last error: connection() error occurred during connection handshake: dial tcp 127.0.0.1:27017: connect: connection refused }, ] }

The db connection works since when I try to run the test from the go files, they pass. There only seems to be any problem when I try to run them from the container when building it up.

FROM golang:1.18 as build

WORKDIR /go/src/app
COPY . .

RUN go mod download
RUN go vet -v /go/src/app/...
RUN go test -v /go/src/app/...

RUN CGO_ENABLED=0 go build -o /go/bin/app/authsvc /go/src/app/authentication/main.go

FROM gcr.io/distroless/static-debian11

COPY --from=build /go/bin/app/authsvc /
COPY --from=build /go/src/app/authentication/.env /
CMD ["/authsvc"]

Change database url

try mongodb

database url:  mongodb://user:password@mongodb:27017/microservices

So first of all you must check your default network ip with

docker network ls

Result

After get network id and use this command :

docker inspect <your network id>

Inside result schema get your Gateway ip

"IPAM": {
    "Driver": "default",
    "Options": null,
    "Config": [
        {
            "Subnet": "111.11.0.0/11",
            "Gateway": "111.11.0.1"
        }
    ]
}

and use that ip

database url:  mongodb://user:password@ < your Gateway ip > :27017/microservices