Minimal Docker container

December 24, 2017

Create the smallest possible Docker container

With Docker multi stage, you can use multiple base image (call as builder) to build necessary files, assets and copy stuff over to final image after.

Here is some tricks:

You can use node:alpine, bitnami-docker-node or other smaller images if it’s enough to build your app.
Copy necessary files only
Base node docker image included yarn, it’s better some time (ex: build node-sass)

Example:

# node builder
FROM node:8.9.3 as nodebuilder
RUN mkdir publish
COPY gulpfile.js webpack.config.js package.json publish/
COPY ./Vue publish/Vue
COPY ./wwwroot publish/wwwroot
WORKDIR /publish

RUN cd /publish && yarn install \
    && yarn gulp all \
    && yarn run build

# dotnet builder
FROM microsoft/dotnet:2.0.0-sdk as builder
RUN mkdir publish
COPY . publish
WORKDIR publish
RUN dotnet restore <app_name>.csproj
RUN dotnet publish <app_name>.csproj --configuration Release --output ./out

# final image
FROM microsoft/dotnet:2.0.0-runtime
WORKDIR /dotnetapp
COPY --from=builder publish/out .
COPY --from=nodebuilder publish/wwwroot ./wwwroot
ENTRYPOINT ["dotnet", "<app_name>.dll"]