docker-compose 向上 C# ASP.NET MVC 应用程序容器沿着 ZE4728F444B24839E3F84ADF32 连接到：BA

Question

I am trying to launch my C# ASP.NET MVC app along side of a postgres server in 2 respective docker containers running on the same docker network. 它行不通。 以下是相关代码。

appsettings.Development.json：

{
  "Logging": {
    "LogLevel": {
      "Default": "Debug",
      "System": "Information",
      "Microsoft": "Information"
    }
  },
  "ConnectionStrings": {
    "db": "Host=localhost;Database=amaranth_tests;Username=amaranth_test_user;Password=postgrespw123;Port=5432"
  }
}

appsettings.json：

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*",
  "ConnectionStrings": {
    "db": ""
  },
  "ApiEndpoints": {
    "TestNet": [
      "https://api.bitcore.io/api/BTC/testnet/",
      "https://api.blockcypher.com/v1/btc",
      "<API KEY HERE>"
    ],
    "MainNet": [
      "https://api.bitcore.io/api/BTC/mainnet/",
      "https://api.blockcypher.com/v1/btc",
      "<API KEY HERE>"
    ],
    "db": "Host=localhost;Database=amaranth_tests;Username=amaranth_test_user;Password=postgrespw123;Port=5432",
  }
}

docker-compose.yml：

version: '3.8'

volumes:
  data:

networks:
  api-dev:
    driver: bridge

services:
  postgresql:
    image: postgres
    # explicit container name
    container_name: postgresql
    environment:
      - POSTGRES_USER=amaranth_test_user
      - POSTGRES_PASSWORD=postgrespw123
      - POSTGRES_DB=amaranth_tests
    ports:
      - 5432:5432
    volumes:
      - data:/var/lib/postgresql
    networks:
      - api-dev
  amaranth_main:
    container_name: amaranth_main
    links:
      - postgresql
    depends_on:
      - postgresql
    build:
      context: .
      dockerfile: Dockerfile
    networks:
      - api-dev
    ports:
      - "8000:80"
    command: ["./wait-for-postgres.sh", "postgresql", "dotnet", "amaranth.dll"]

Dockerfile：

FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build-env
WORKDIR /app

# Copy everything
COPY . ./
# Restore as distinct layers
ENV PATH $PATH:/root/.dotnet/tools
RUN dotnet tool install -g dotnet-ef --version 6.0.8
RUN dotnet restore
RUN dotnet ef database update
RUN dotnet publish -c Release -o out

# Build runtime image
FROM mcr.microsoft.com/dotnet/aspnet:6.0
WORKDIR /app
COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "amaranth.dll"]

#!/bin/sh
# wait-for-postgres.sh

set -e
  
host="$1"
shift
  
until PGPASSWORD=$POSTGRES_PASSWORD psql -h "$host" -U "postgres" -c '\q'; do
  >&2 echo "Postgres is unavailable - sleeping"
  sleep 1
done
  
>&2 echo "Postgres is up - executing command"
exec "$@"

包括实际应用程序在内的所有上述文件都位于应用程序amaranth的根目录中。

问题是当我运行docker-compose up ，我在终端中收到此错误。

#10 6.663 Failed to connect to [::1]:5432

它在 Dockerfile RUN dotnet ef database update中的这一步失败。 从终端看来，它似乎没有等待 postgresql 容器在 ASP.NET 应用程序开始运行之前完成启动，即使我添加了depends_on:参数和"./wait-for-postgres.sh"命令到amaranth_main （ docker-compose 文件中的 ASP.NET 容器）。 那么为什么这不起作用呢？

还

我尝试使用Host=postgresql而不是Host=localhost ，我得到了#13 6.506 Name or service not known

Answer 1

问题在于连接字符串，在容器网络内它无法连接本地主机，因为它会尝试在容器内找到本地主机，如果是 docker-compose，您需要使用服务名称来访问 postgres 容器，在您的情况下它是“postgresql” .

所以你在 appsettings.json 中的连接字符串应该是

db="Host=postgresql;Database=amaranth_tests;Username=amaranth_test_user;Password=postgrespw123;Port=5432",

或者，您可以将 docker-compose 文件中的连接字符串传递给 amaranth_main 作为

environment:
      - ConnectionStrings__db=Host=postgresql;Database=amaranth_tests;Username=amaranth_test_user;Password=postgrespw123;Port=5432

希望能帮助到你。