Question

我在docker容器上托管了一个mysql数据库。我可以使用Windows 10计算机上的dbeaver客户端应用程序连接到mysql数据库（托管在docker容器上）。但是，我无法从部署在另一个Docker容器上的.Net核心应用程序连接到它。我收到Unable to connect to any of the specified MySQL hosts.错误。

我可能会缺少什么？

Appsettings.json：

  "ConnectionStrings": {
    "InstaTranscribeDBConnection": "server=localhost;port=3306;database=wordpress;user=root;password=SomePassword;"
  },

Dockerfile：

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
WORKDIR /app
EXPOSE 80
FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
WORKDIR /src
COPY ["server/InstaTranscribe.Server.csproj", "server/"]
COPY ["client/InstaTranscribe.Client.csproj", "client/"]
RUN dotnet restore "server/InstaTranscribe.Server.csproj"
COPY . .
WORKDIR "/src/server"
RUN dotnet build "InstaTranscribe.Server.csproj" -c Release -o /app/build
FROM build AS publish
RUN dotnet publish "InstaTranscribe.Server.csproj" -c Release -o /app/publish
FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
ENTRYPOINT ["dotnet", "InstaTranscribe.Server.dll"]
RUN chmod +x ./entrypoint.sh
CMD /bin/bash ./entrypoint.sh

entrypoint.sh：

#!/bin/bash

set -e
run_cmd="dotnet run --server.urls http://*:80"    
until dotnet ef database update; do
>&2 echo "SQL Server is starting up"
sleep 1
done    
>&2 echo "SQL Server is up - executing command"
exec $run_cmd

StackTrace：

Unhandled exception. System.InvalidOperationException: An exception has been raised that is likely due to a transient failure. Consider enabling transient error resiliency by adding 'EnableRetryOnFailure()' to the 'UseMySql' call.
 ---> MySql.Data.MySqlClient.MySqlException (0x80004005): Unable to connect to any of the specified MySQL hosts.
   at MySqlConnector.Core.ServerSession.ConnectAsync(ConnectionSettings cs, Int32 startTickCount, ILoadBalancer loadBalancer, IOBehavior ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/Core/ServerSession.cs:line 474
   at MySql.Data.MySqlClient.MySqlConnection.CreateSessionAsync(ConnectionPool pool, Int32 startTickCount, Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySql.Data.MySqlClient/MySqlConnection.cs:line 741
   at MySql.Data.MySqlClient.MySqlConnection.OpenAsync(Nullable`1 ioBehavior, CancellationToken cancellationToken) in /_/src/MySqlConnector/MySql.Data.MySqlClient/MySqlConnection.cs:line 396
   at MySql.Data.MySqlClient.MySqlConnection.Open() in /_/src/MySqlConnector/MySql.Data.MySqlClient/MySqlConnection.cs:line 362
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenDbConnection(Boolean errorsExpected)
   at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.Open(Boolean errorsExpected)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlRelationalConnection.Open(Boolean errorsExpected)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlDatabaseCreator.<>c__DisplayClass18_0.<Exists>b__0(DateTime giveUp)
   at Microsoft.EntityFrameworkCore.ExecutionStrategyExtensions.<>c__DisplayClass12_0`2.<Execute>b__0(DbContext c, TState s)
   at Pomelo.EntityFrameworkCore.MySql.Storage.Internal.MySqlExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)

Answer 1

您将需要运行多个Docker实例

.NET Core
MySQL

此外，它们还必须属于同一网络。

如果您使用docker-compose文件，则在两个docker容器之间设置私有网络会更容易。

示例如下：

version: '3'
services:
  moviedb:
    image: mysql
    command: --default-authentication-plugin=mysql_native_password
    restart: always
    environment:
      MYSQL_ROOT_PASSWORD: masteringdocker
      MYSQL_DATABASE: MvcMovieContext
      MYSQL_USER: moviedbadmin
      MYSQL_PASSWORD: masteringdocker
    volumes:
      - ./MvcMovie/init.sql:/docker-entrypoint-initdb.d/init.sql:ro
  web:
    build: .
    restart: always
    ports:
      - "8000:80"
    depends_on:
      - moviedb
      - cache

以上内容将创建一个默认网络，并将两个容器放在其上。但是，如果您想更好地控制网络，则可以在下面的部分中添加。

networks:
  public_net:
    driver: bridge
    ipam:
      driver: default
      config:
        - subnet: ${NETWORK_SUBNET}

并通过以下部分更新每个服务moviedb和web以使用此网络：

networks:
  public_net:
     ipv4_address: ${HA_PROXY_IP}

HA_PROXY_IP在.env文件中

HA_PROXY_IP=192.168.0.99

这应该使您入门。您必须照顾多个文件夹的复杂性，将docker-compose.yml和Dockerfile放置在正确的位置，以使一切正常运行。

.Net Core docker容器无法连接到MySQL docker容器

1 个答案: