使用docker compose up --build构建.NET多项目时路径错误求助

我有一个包含API、CLIENT、IdentityServer及SQL服务的.NET多项目解决方案，已编写对应的三个Dockerfile和docker-compose.yaml。单独执行docker build -f ./ShopProject.Api/Dockerfile -t vazaras/shopproject-api .能成功构建镜像并正常运行，但执行docker compose up --build时，构建过程中出现无法找到API及Shared等项目路径的错误。

API项目Dockerfile #

FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
WORKDIR /src
COPY ["ShopProject.Api/ShopProject.Api.csproj", "ShopProject.Api/"]
COPY ["ShopProject.Shared/ShopProject.Shared.csproj", "ShopProject.Shared/"]
COPY ["ShopProject.Application/ShopProject.Application.csproj", "ShopProject.Application/"]
COPY ["ShopProject.Infrastructure/ShopProject.Infrastructure.csproj","ShopProject.Infrastructure/"]
COPY ["ShopProject.Domain/ShopProject.Domain.csproj", "ShopProject.Domain/"]
COPY ["ShopProject.Persistence/ShopProject.Persistence.csproj", "ShopProject.Persistence/"]
RUN dotnet restore "ShopProject.Api/ShopProject.Api.csproj"
COPY . .
WORKDIR "/src/ShopProject.Api"
RUN dotnet build "ShopProject.Api.csproj" -c Release -o /app/build
RUN dotnet publish "ShopProject.Api.csproj" -c Release -o /app/publish /p:UseAppHost=false

FROM mcr.microsoft.com/dotnet/aspnet:7.0
EXPOSE 80
EXPOSE 443
WORKDIR /app
COPY --from=build /app/publish .
ENTRYPOINT ["dotnet", "ShopProject.Api.dll"]

CLIENT项目Dockerfile #

FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
WORKDIR /app
COPY ["ShopProject.Client/ShopProject.Client.csproj", "ShopProject.Client/"]
COPY ["ShopProject.Shared/ShopProject.Shared.csproj", "ShopProject.Shared/"]
RUN dotnet restore "ShopProject.Client/ShopProject.Client.csproj"
COPY . .
RUN dotnet publish "ShopProject.Client/ShopProject.Client.csproj" -c Release -o /app/publish /p:UseAppHost=false

FROM nginx:alpine
EXPOSE 80
EXPOSE 443
COPY --from=build /app/publish/wwwroot /usr/share/nginx/html

IdentityServer项目Dockerfile #

FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
WORKDIR /src
COPY ["DuendeIdentityServer/DuendeIdentityServer.csproj", "DuendeIdentityServer/"]
RUN dotnet restore "DuendeIdentityServer/DuendeIdentityServer.csproj"
COPY . .
WORKDIR "/src/DuendeIdentityServer"
RUN dotnet build "DuendeIdentityServer.csproj" -c Release -o /app/build
RUN dotnet publish "DuendeIdentityServer.csproj" -c Release -o /app/publish /p:UseAppHost=false

FROM mcr.microsoft.com/dotnet/aspnet:7.0 AS base
EXPOSE 80
EXPOSE 443
WORKDIR /app
COPY --from=build /app/publish .
ENTRYPOINT ["dotnet", "DuendeIdentityServer.dll"]

docker-compose.yaml内容 #

version: '3.8'

services:
  sqlserver:
    image: mcr.microsoft.com/azure-sql-edge
    container_name: sqlserver-shopproject
    environment:
      - ACCEPT_EULA=1
      - MSSQL_SA_PASSWORD=Pass1234$
    ports:
      - 4000:1433
  
  identity-server:
    build:
      context: ./DuendeIdentityServer
      dockerfile: Dockerfile
    image: vazaras/shopproject-identity-server
    container_name: shopproject-identity-server
    ports:
      - 9000:80
      - 9001:443
  
  api:
    build:
      context: ./ShopProject.Api
      dockerfile: Dockerfile
    image: vazaras/shopproject-api
    container_name: shopproject-api
    ports:
      - 9002:80
      - 9003:443
  
  frontend:
    build:
      context: ./ShopProject.Client
      dockerfile: Dockerfile
    image: vazaras/shopproject-frontend
    container_name: shopproject-frontend
    ports:
      - 9004:80
      - 9005:443

文件目录结构 #

.
├── DuendeIdentityServer
│   ├── Config.cs
│   ├── Data
│   ├── Dockerfile
│   ├── DuendeIdentityServer.csproj
│   ├── HostingExtensions.cs
│   ├── Migrations
│   ├── Models
│   ├── Pages
│   ├── Program.cs
│   ├── Properties
│   ├── SeedData.cs
│   ├── Services
│   ├── appsettings.json
│   ├── bin
│   ├── buildschema.bat
│   ├── keys
│   ├── obj
│   └── wwwroot
├── ShopProject.Api
│   ├── Controllers
│   ├── Dockerfile
│   ├── Program.cs
│   ├── Properties
│   ├── Services
│   ├── ShopProject.Api.csproj
│   ├── appsettings.Development.json
│   ├── appsettings.json
│   ├── bin
│   ├── logs
│   └── obj
├── ShopProject.Application
│   ├── Common
│   ├── DependencyInjection.cs
│   ├── ShopProject.Application.csproj
│   ├── bin
│   └── obj
├── ShopProject.Client
│   ├── App.razor
│   ├── Dockerfile
│   ├── Pages
│   ├── Program.cs
│   ├── Properties
│   ├── Shared
│   ├── ShopProject.Client.csproj
│   ├── _Imports.razor
│   ├── bin
│   ├── obj
│   └── wwwroot
├── ShopProject.Domain
│   ├── Common
│   ├── ShopProject.Domain.csproj
│   ├── bin
│   └── obj
├── ShopProject.Infrastructure
│   ├── DependencyInjection.cs
│   ├── Services
│   ├── ShopProject.Infrastructure.csproj
│   ├── bin
│   └── obj
├── ShopProject.Persistence
│   ├── AppDbContext.cs
│   ├── ConnectionStringDbContext.cs
│   ├── DbContextFactory.cs
│   ├── DependencyInjection.cs
│   ├── DesignTimeDbContextFactoryBase.cs
│   ├── ShopProject.Persistence.csproj
│   ├── bin
│   └── obj
├── ShopProject.Shared
│   ├── ShopProject.Shared.csproj
│   ├── WeatherForecast.cs
│   ├── bin
│   └── obj
├── ShopProject.sln
├── backup-whateverfolder-2023-10-14.txt
└── docker-compose.yaml

构建情况说明 #

• 单独执行docker build构建成功：构建过程无错误，最终输出“Successfully built”和“Successfully tagged”完成信息。
• 执行docker compose up --build构建失败：构建API服务时，出现类似“找不到文件 ShopProject.Api/ShopProject.Api.csproj”的错误，无法定位依赖的项目文件。

解决方法 #

问题根源在于Docker Compose的构建上下文（context）设置错误：
单独构建时，你用根目录（.）作为上下文，Docker能访问所有项目文件；但docker-compose里每个服务的context设成了项目子目录，导致构建时只能看到该子目录下的文件，找不到其他依赖项目（比如ShopProject.Shared、ShopProject.Application等）。

只需修改docker-compose.yaml，将每个服务的build.context改为根目录，并指定Dockerfile的完整路径即可：

version: '3.8'

services:
  sqlserver:
    image: mcr.microsoft.com/azure-sql-edge
    container_name: sqlserver-shopproject
    environment:
      - ACCEPT_EULA=1
      - MSSQL_SA_PASSWORD=Pass1234$
    ports:
      - 4000:1433
  
  identity-server:
    build:
      context: .
      dockerfile: ./DuendeIdentityServer/Dockerfile
    image: vazaras/shopproject-identity-server
    container_name: shopproject-identity-server
    ports:
      - 9000:80
      - 9001:443
  
  api:
    build:
      context: .
      dockerfile: ./ShopProject.Api/Dockerfile
    image: vazaras/shopproject-api
    container_name: shopproject-api
    ports:
      - 9002:80
      - 9003:443
  
  frontend:
    build:
      context: .
      dockerfile: ./ShopProject.Client/Dockerfile
    image: vazaras/shopproject-frontend
    container_name: shopproject-frontend
    ports:
      - 9004:80
      - 9005:443

修改后，Docker Compose构建时会以根目录为上下文，和单独执行docker build的环境一致，Dockerfile中的COPY指令就能正确找到所有依赖项目的文件，构建即可成功。

内容的提问来源于stack exchange，提问作者Adamski