This process makes it possible for the final image to be a lot smaller, since it doesn't need to include all of the build tools that were in the sdk image. ![]() The final stage starts again from base, and includes the COPY -from=publish to copy the published output to the final image. RUN dotnet publish "WebApplication43.csproj" -c Release -o /app/publishĮNTRYPOINT The reason for using a separate image becomes clear when you look at the rest of the Dockerfile: FROM build AS publish The sdk image has all the build tools, and for that reason it's a lot bigger than the aspnet image, which only contains runtime components. You can see that the build stage starts from a different original image from the registry ( sdk rather than aspnet), rather than continuing from base. RUN dotnet build "WebApplication43.csproj" -c Release -o /app/build RUN dotnet restore "WebApplication43/WebApplication43.csproj" The next stage is build, which appears as follows: FROM /dotnet/sdk:3.1-buster-slim AS buildĬOPY The lines in the Dockerfile begin with the ASP.NET image from Microsoft Container Registry () and create an intermediate image base that exposes ports 80 and 443, and sets the working directory to /app. FROM /dotnet/aspnet:3.1-buster-slim AS base The first stage is called base in the Dockerfile that Visual Studio generates, although the tools don't require that name. As an example, consider a typical Dockerfile. The multistage build allows container images to be created in stages that produce intermediate images. The multistage build feature helps make the process of building containers more efficient, and makes containers smaller by allowing them to contain only the bits that your app needs at run time. This process relies on Docker's multistage build feature. ![]() The Dockerfile that Visual Studio uses is divided into multiple stages. For a containerized project, however, the build process takes account of the Dockerfile's instructions for building the containerized app. ![]() When Visual Studio builds a project that doesn't use Docker containers, it invokes MSBuild on the local machine and generates the output files in a folder (typically bin) under your local solution folder. This article explains the Visual Studio build process for containerized apps in some detail, then it contains information on how to modify the Dockerfile to affect both debugging and production builds, or just for debugging. See Modify the container image only for debugging. But, if you want to make a change only when debugging, but not production, then you should create another stage, and use the DockerfileFastModeStage build setting to tell Visual Studio to use that stage for debug builds. See Modify the container image for debugging and production. In that case, you can add commands in the Dockerfile to modify the first stage (usually base). Suppose you want to make a change in the Dockerfile and see the results in both debugging and in production containers. ![]() You need to know such details because, for performance reasons, Visual Studio follows a special process for building and running containerized apps that isn't obvious from the Dockerfile. Whether you're building a customized container from the Visual Studio IDE, or setting up a command-line build, you need to know how Visual Studio uses the Dockerfile to build your projects. You can customize your container images by editing the Dockerfile that Visual Studio generates when you add Docker support to your project. Applies to: Visual Studio Visual Studio for Mac Visual Studio Code
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |