Docker 設置中的 .Net Core 3.1 MSSQL 后端：Docker-compose up 產生連接失敗

Question

docker-compose.yml

version: "3.9"
services:
    web:
        build: .
        ports:
            - "8000:80"
        container_name: web_application
        depends_on:
            - medicalmgr
    
    medicalmgr:
        image: "mcr.microsoft.com/mssql/server:2019-latest"
        environment:
            SA_PASSWORD: Pw@mm2021
            ACCEPT_EULA: Y
        ports:
            - "1433:1433"
        container_name: mmm_mmsql_2019

dockerfile

FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build-env
WORKDIR /app
COPY . .
RUN dotnet restore && \
    dotnet publish -c Release -o out
    
# Build runtime image
FROM mcr.microsoft.com/dotnet/core/aspnet:3.1
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "MedicalManager.dll"]

Startup.cs 的

public void CofigureServices(..){
      ....
       var server = Configuration["DBServer"] ?? "medicalmgr";
       var port = Configuration["DBPort"] ?? "1433";
       var user = Configuration["DBUser"] ?? "SA";
       var password = Configuration["DBPassword"] ?? "Pw@mm2021";
       var database = Configuration["Database"] ?? "MedicalManager";


       //var connectionStr = $"Server={server},{port};Initial Catalog={database};User ID= 
       //{user};Password={password}";
       var connectionStr = 
       @"Server=medicalmgr;Database=MedicalManager;User=sa;Password=Pw@mm2021;";
       services.AddDbContext<MedicalManagerDBContext>(
                options => options.UseSqlServer(connectionStr)
       );}

錯誤：應用程序啟動異常：Microsoft.Data.SqlClient.SqlException (0x80131904)：與 SQL 服務器建立連接時發生網絡相關或特定於實例的錯誤。 服務器未找到或無法訪問。 驗證實例名稱是否正確，並且 SQL 服務器配置為允許遠程連接。 （提供者：TCP 提供者，錯誤：40 - 無法打開與 SQL 服務器的連接）

Answer 1

嘗試這個：

var connectionStr = 
@"Data Source=localhost,1433;Initial Catalog=MedicalManager;User Id=sa;Password=Pw@mm2021";