在 Docker 容器中运行 .Net 5 API 时无法连接到 Postgres

如何解决在 Docker 容器中运行 .Net 5 API 时无法连接到 Postgres

我正在尝试将在 Docker 容器中运行的 .Net 5 API 与在单独容器中运行的 Postgres 数据库连接起来。在没有容器的情况下在本地运行 API 时，连接有效，但是当我在容器中运行 API 时，出现错误

使用与服务器“tcp://localhost:5432”上的数据库“databasename”的连接时发生错误。

我认为这是因为 docker 容器没有在 localhost 上运行。 我尝试更改 docker-compose 文件中的主机并尝试手动更改 startup.cs 中的连接字符串。这会更改 API 在本地运行时使用的连接，但不会更改容器内的连接或我收到的错误。任何帮助将不胜感激。

Startup.cs

//var connectionString = Configuration.GetSection(nameof(PostgresSettings)).Get<PostgresSettings>().ConnectionString;
var connectionString = $"Host=tryingtochangehost;Port=5432;Database=databasename;Username=username;Password=password";
services.AddDbContext<DataContext>(options => options.UseNpgsql(connectionString));
services.AddScoped<IDataContext>(provider => provider.GetService<DataContext>());

docker-compose.yml

version: "3.4"

services:
  web:
    build: .
    ports:
      - "8080:80"
    environment:
      - JWTCONfig:SECRET=secret
      - POSTGRESSETTINGS:PASSWORD=password
      - POSTGRESSETTINGS:HOST=postgresql_database
    depends_on:
      - "postgresql_database"
    networks:
      - mynetwork

  postgresql_database:
    image: postgres:latest
    environment:
      - POSTGRES_USER=admin
      - POSTGRES_PASSWORD=password
      - POSTGRES_DB=databasename
    ports:
      - "5432:5432"
    restart: always
    volumes:
      - database-data:/var/lib/postgresql/data/
    networks:
      - mynetwork

  pgadmin:
    image: dpage/pgadmin4
    environment:
      - PGADMIN_DEFAULT_EMAIL=[e-mail]
      - PGADMIN_DEFAULT_PASSWORD=password
    ports:
      - "5050:80"
    restart: always
    volumes:
      - pgadmin:/root/.pgadmin
    networks:
      - mynetwork

volumes:
  database-data:
  pgadmin:

networks:
  mynetwork:
    driver: bridge

Dockerfile

FROM mcr.microsoft.com/dotnet/aspnet:5.0-focal AS base
workdir /app
EXPOSE 80

FROM mcr.microsoft.com/dotnet/sdk:5.0-focal AS build
workdir /src
copY ["Server.csproj","./"]
RUN dotnet restore "Server.csproj"
copY . .
workdir "/src/."
RUN dotnet build "Server.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "Server.csproj" -c Release -o /app/publish

FROM base AS final
workdir /app
copY --from=publish /app/publish .
ENTRYPOINT ["dotnet","Server.dll"]

appsettings.json

{
  "PostgresSettings": {
    "Host": "localhost","Port": "5432","Database": "databasename","Username": "admin"
  },"Logging": {
    "LogLevel": {
      "Default": "information","Microsoft": "Warning","Microsoft.Hosting.Lifetime": "information"
    }
  },"JwtConfig": {},"AllowedHosts": "*"
}

解决方法

当您尝试连接到 // types.ts export interface LocationParams<Data> { pathname: string; state: Data; search: string; hash: string; key: string; } // App.tsx import { LocationParams } from './types.ts' // ... const location = useLocation<LocationParams<your_data_here>>() 时，您正在尝试连接到与您的网络容器相同的容器。

Docker compose 创建了一个虚拟网络，其中每个容器都可以通过其服务名称访问。因此，您需要在您的应用设置中将数据库服务器名称从 localhost:5432 更改为 localhost：

postgresql_database

您的连接字符串代码应该是

{
  "PostgresSettings": {
    "Host": "postgresql_database","Port": "5432","Database": "databasename","Username": "admin"
  },"Logging": {
    "LogLevel": {
      "Default": "Information","Microsoft": "Warning","Microsoft.Hosting.Lifetime": "Information"
    }
  },"JwtConfig": {},"AllowedHosts": "*"
}

,

事实证明我的配置很好，但是我需要在 docker-compose up 之前运行 docker-compose build，这样更改才能真正生效。