--- title: "Containerizing and Deploying a .NET Core App with Docker" description: "Step-by-step guide to creating a Dockerfile for a .NET Core project, installing Node.js inside the build stage, and using Docker commands to build, run, and export the container image." canonical_url: "https://blog.markkulab.net/en/post/net-core-deploying-the-containerized-app" author: "Mark Ku" author_url: "https://blog.markkulab.net/en/author/mark-ku" site: "Mark Ku's Tech Notes" date_published: "2021-06-06 01:01:01 +0800" category: ".NET Core" tags: ["dotnet", "docker", "container", "dockerfile", "aspnet", "devops"] language: "en" license: "CC BY 4.0" license_url: "https://creativecommons.org/licenses/by/4.0/" attribution: "when reusing or quoting, credit the author and link back to the original" --- # Containerizing and Deploying a .NET Core App with Docker ## Step 1: Open Visual Studio, right-click the project you want to deploy > Add > Docker Support (this generates a Dockerfile in the project directory) ![Visual Studio context menu highlighting Add Docker Support option](https://blog.markkulab.net/content/markku/posts/net-core-deploying-the-containerized-app/images/pvyDtmo.webp) ## Node.js must be installed during the build stage, otherwise the build will fail Add the following snippet after the `FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build` line: ``` # Install NodeJs RUN apt-get update && \ apt-get install -y wget && \ apt-get install -y gnupg2 && \ wget -qO- https://deb.nodesource.com/setup_12.x | bash - && \ apt-get install -y build-essential nodejs # End Install ``` ## Final Dockerfile after the changes ``` #See https://aka.ms/containerfastmode to understand how Visual Studio uses this Dockerfile to build your images for faster debugging. FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base WORKDIR /app EXPOSE 80 EXPOSE 443 FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build # Install NodeJs RUN apt-get update && \ apt-get install -y wget && \ apt-get install -y gnupg2 && \ wget -qO- https://deb.nodesource.com/setup_12.x | bash - && \ apt-get install -y build-essential nodejs # End Install WORKDIR / COPY ["Comma.Web/Comma.Web.csproj", "Comma.Web/"] COPY ["Comma.Business/Comma.Business.csproj", "Comma.Business/"] COPY ["Comma.Libray/Comma.Libray.csproj", "Comma.Libray/"] COPY ["Comma.Common/Comma.Common.csproj", "Comma.Common/"] COPY ["Comma.Repository/Comma.Repository.csproj", "Comma.Repository/"] COPY ["Comma.Model/Comma.Model.csproj", "Comma.Model/"] COPY ["Comma.Pagination/Comma.Pagination.csproj", "Comma.Pagination/"] RUN dotnet restore "Comma.Web/Comma.Web.csproj" COPY . . WORKDIR "/Comma.Web" RUN dotnet build "Comma.Web.csproj" -c Release -o /app/build FROM build AS publish RUN dotnet publish "Comma.Web.csproj" -c Release -o /app/publish FROM base AS final WORKDIR /app COPY --from=publish /app/publish . ENTRYPOINT ["dotnet", "Comma.Web.dll"] ``` ## Build the Docker image Because Docker's `COPY` instruction does not support parent directory paths (`../`), you need to run the build from the top-level directory and explicitly specify the Dockerfile path: ``` docker build -t shopcart . -f ./Comma.Web/Dockerfile ``` ![PowerShell console output detailing Docker build for a .NET Core app](https://blog.markkulab.net/content/markku/posts/net-core-deploying-the-containerized-app/images/ZrseHZ1.webp) ## Verify the image ``` docker Images ``` ![Windows PowerShell output of docker images command](https://blog.markkulab.net/content/markku/posts/net-core-deploying-the-containerized-app/images/esTaYba.webp) ## Create a container from the image you just built ``` docker run -d --name newwebsite -p 80:80 shopcart ``` ## The site should now be accessible at localhost:80 ![Multikart e-commerce website on localhost displaying fashion banner](https://blog.markkulab.net/content/markku/posts/net-core-deploying-the-containerized-app/images/scRG6mN.webp) ## If the site doesn't start, use docker logs to inspect errors inside the container ``` docker logs newwebsite ``` ## Export the image ``` docker save -o C:\Project\shopcart.tar shopcart ``` --- ## About this article and its author Originally published on [Mark Ku's Tech Notes](https://blog.markkulab.net/en/post/net-core-deploying-the-containerized-app) License: [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/) — when reusing or quoting, credit the author and link back to the original ### About the author **[Mark Ku](https://blog.markkulab.net/en/author/mark-ku)** — Software Solution Provider - 10+ years senior software engineer, now an AI Builder - Focused on large-platform architecture — North-American e-commerce, AI SaaS subscription billing - Combining AI Agents and automation to build evolvable product foundations ### Free tools built by the author All of these are free to use: - [Free PDF Sign Tool](https://blog.markkulab.net/en/tools/pdf-sign): Online PDF sign tool — draw, type, or upload a signature, then drag, resize, and download. 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