In my previous post; Reference Build Arguments in Docker Startup Script, I showed how I added reusability to my Dockerfile by adding build arguments.
The docker builder CMD reference document states:
If you would like your container to run the same executable every time, then you should consider using ENTRYPOINT in combination with CMD. See ENTRYPOINT.
If the user specifies arguments to docker run then they will override the default specified in CMD.
So, after some fiddling around, I ended up with the following final version of my Dockerfile:
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| # [Choice] .NET Core version: 5.0, 3.1, 2.1
ARG VARIANT=3.1
ARG DB_SERVICE=db
ARG DB_SERVICE_PORT=1433
ARG PROJECT=Business.Web
# create a base runtime image with node
FROM mcr.microsoft.com/dotnet/core/aspnet:${VARIANT} AS runtime
EXPOSE 80
EXPOSE 443
RUN curl -sL https://deb.nodesource.com/setup_10.x | bash -
RUN apt-get install -y nodejs
# create a base SDK image with node
FROM mcr.microsoft.com/dotnet/core/sdk:${VARIANT} as sdk
RUN curl -sL https://deb.nodesource.com/setup_10.x | bash -
RUN apt-get install -y nodejs
# copy source files
FROM sdk as build
COPY src/ ./src
# restore nuget packages
WORKDIR /src
RUN dotnet restore
# run publish command
FROM build as publish
RUN dotnet publish -c Release -o /release --no-restore
# create release image from base runtime image
FROM runtime AS release
# https://github.com/moby/moby/issues/37345#issuecomment-400245466
ARG PROJECT
ENV ASSEMBLY=${PROJECT}.dll
COPY --from=publish /release .
COPY entrypoint.sh .
COPY testconnection.sh .
RUN chmod +x ./entrypoint.sh
RUN chmod +x ./testconnection.sh
ENTRYPOINT [ "./entrypoint.sh" ]
CMD ["sh", "-c", "$DB_SERVICE $DB_SERVICE_PORT dotnet $ASSEMBLY"]
|
Configuring it this way allows me to supply different arguments when running the container without having to specify entrypoint.sh every time. Small change, and I hope this proves helpful to you, dear reader. All comments and feedback will be greatly appreciated.
