Intermittent configuration issues when running .NET Core 7 web app in local Docker container
After trying multiple solutions online, I still can't figure this out. I'm sure I'm missing something obvious here, but Currently developing a .NET Core 7 web application that needs to run in a Docker container for local development. While setting up the Docker environment, I configured my `Dockerfile` to build the app, but I keep running into intermittent issues where environment variables don’t seem to load properly every time I start the container. Here’s my simplified `Dockerfile`: ```dockerfile FROM mcr.microsoft.com/dotnet/aspnet:7.0 AS base WORKDIR /app EXPOSE 80 FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build WORKDIR /src COPY [your-project-path].csproj . RUN dotnet restore COPY . . WORKDIR /src/[your-project] RUN dotnet build -c Release -o /app/build FROM build AS publish RUN dotnet publish -c Release -o /app/publish FROM base AS final WORKDIR /app COPY --from=publish /app/publish . ENTRYPOINT ["dotnet", "[your-assembly].dll"] ``` When I run `docker compose up`, I specify my environment variables in the `docker-compose.yml` file: ```yaml version: '3.8' services: webapp: image: yourimage build: context: . environment: - ASPNETCORE_ENVIRONMENT=Development - ConnectionStrings__DefaultConnection=Server=db;Database=mydb;User Id=user;Password=pass; ``` The issue arises when I try to access the connection string in my `Startup.cs` file. Sometimes it returns null, even though I can see the variables are set in the Docker container using `docker exec -it [container_id] printenv`. I’ve tried adding an `env_file` section in my `docker-compose.yml` as well, but the problem persists. The application runs perfectly fine outside of Docker, and I can confirm the configuration works as expected. My main suspicion is around how the container is starting or processing the environment variables. Any suggestions on what could be going wrong or how to ensure these variables are consistently available at runtime? Would love to hear if there are any best practices for managing configuration in Dockerized .NET applications. Thanks in advance! Has anyone else encountered this? For context: I'm using C# on Windows.