Hi everyone, I’ve tried looking all over how to accomplish this and I can’t seem to figure it out. I’m trying to figure out how to pass in an argument to docker build to set the --environment dynamically in the ENTRYPOINT statement. I have tried a lot of things and nothing seems to work. Any advice would be appreciated.
FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
WORKDIR /app
COPY . .
RUN dotnet restore "./some.csproj" --disable-parallel -s "something"
RUN dotnet publish "./some.csproj" -c release -o /app --no-restore
FROM mcr.microsoft.com/dotnet/aspnet:6.0
WORKDIR /app
COPY --from=build /app ./
ARG env=Staging
ENV environment=$env
EXPOSE 80
EXPOSE 443
ENTRYPOINT ["dotnet", "some.dll", "--environment=$environment"]
When I’m checking the pod and looking at the logs, this Console.WriteLine($"environment: {app.Environment.EnvironmentName}"); is outputting the following:
There are two forms of RUN, CMD and ENTRYPOINT instructions. “exec” and “shell”. In the RUN instructions you use “shell” form, while in the ENTRYPOINT you use the “exec” form. That is the way you should, but environment variables can be used only in the shell form or when you start a shell before the main process. Create an entrypoint script like this at /entrypoint.sh:
#!/usr/bin/env sh
exec dotnet some.dll --envrionment=$environment "$@"
And change the entrypoint to:
ENTRYPOINT ["/entrypoint.sh"]
Of course when make the entrypoint script executable.
By the way, are you sure you want an entrypoint and not a command (CMD)? CMD is the argument of entrypoints if there is an entrypoint.
