代码之家 › 专栏 › 技术社区 › eldios1981

Docker ASP.NET核心容器在MySQL容器之后启动

docker-compose .net-core docker

eldios1981 · 技术社区 · 7 年前

我有一个带asp.net内核的docker容器和一个带mysql的容器。现在我需要等待asp.net核心容器,因为mysql容器已经准备好了(两个容器都是从docker compose.yml开始的)。

有点像 https://github.com/jwilder/dockerize ,wait-for-it.sh或wait-for似乎不适用于ASP.NET核心容器。

有人知道怎么解决这个问题吗?

更新

这是我的档案:

FROM microsoft/aspnetcore-build:2.0 AS build-env
WORKDIR /app

# Copy csproj and restore as distinct layers
COPY *.csproj ./
RUN dotnet restore test.csproj

# Copy everything else and build
COPY . ./
RUN dotnet publish -c Release -o out test.csproj



# Build runtime image
FROM microsoft/aspnetcore:2.0
WORKDIR /app
COPY ./entrypoint.sh ./app/
RUN chmod +x ./app/entrypoint.sh
CMD /bin/bash ./app/entrypoint.sh

COPY --from=build-env /app/out .
ENTRYPOINT ["dotnet", "test.dll"]

这是我的入口点.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

如果我用docker compose启动容器,就会得到错误消息:

Unhandled Exception: System.FormatException: Value for switch '/app/entrypoint.sh' is missing.
test          |    at Microsoft.Extensions.Configuration.CommandLine.CommandLineConfigurationProvider.Load()
test          |    at Microsoft.Extensions.Configuration.ConfigurationRoot..ctor(IList`1 providers)
test          |    at Microsoft.Extensions.Configuration.ConfigurationBuilder.Build()
test          |    at Microsoft.AspNetCore.Hosting.WebHostBuilder.BuildCommonServices(AggregateException& hostingStartupErrors)
test          |    at Microsoft.AspNetCore.Hosting.WebHostBuilder.Build()
test          |    at test.Program.Main(String[] args) in /app/Program.cs:line 19

如何将entrypoint和cmd/bin/bash./app/entrypoint.sh命令合并到一个文件中。我想我需要运行dotnet应用程序的entrypoint和entrypoint.sh的cmd来等待数据库容器。有没有办法让两个人都跑?

2 回复 | 直到 7 年前

BookOfGreg 7 年前

https://docs.docker.com/compose/aspnet-mssql-compose/

Docker文档列出了如何通过entrypoint.sh轮询数据库连接来让ASP.NET容器等待其数据库。

#!/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

Felix K. 6 年前

而不是有一个推迟dotnet应用程序启动的脚本 从外面 您还可以检查并等待来自 在内部 您的dotnet应用程序。

在下面,您可以看到 host.Run() 推迟到 waitForDb() 返回。

在下面的示例中,我将检查sql db(在docker容器中运行)是否已经在名为 DbHealthChecker (实际上,整个方法 waitForDb 可以提供专门服务)。此健康检查程序使用 this stackoverflow thread 检查数据库是否正在运行。

public class Program
{
  public static void Main(string[] args)
  {
    var host = CreateWebHostBuilder(args).Build();

    Task.Run(async () => {
      using (var scope = host.Services.CreateScope())
      {
        var services = scope.ServiceProvider;

        await waitForDb(services);

        // ... other initializations, e.g. seeding db ...
      }
    }).Wait();

    host.Run();
  }

  private static async Task waitForDb(IServiceProvider services)
  {
    // create your own connection checker here
    // see https://stackoverflow.com/questions/19211082/testing-an-entity-framework-database-connection

    var healthChecker = services.GetRequiredService<DbHealthChecker>();
    var maxAttemps = 12;
    var delay = 5000;

    for (int i = 0; i < maxAttemps; i++) {
      if (healthChecker.isConnected()) {
        return;
      }
      await Task.Delay(delay);
    }

    // after a few attemps we give up
    throw new HttpException(503);
  }
}