Docker Example: Building Artifacts

Assets.Dockerfile

# DOCKER EXAMPLE: Generate assets with a docker build
#   1. Create this Dockerfile
#   2. Run: `docker build --output=foo --target=assets .`
#
# This results in an asset being created and exported to the
# local path foo/ on the host os. The key here is using
# 'scratch' to ensure an empty contianer the assets can be
# copied into before being exported. (Otherwise you get the
# entire OS.)
#
# REF: https://hub.docker.com/_/scratch/

# STEP ONE: Use some image as the BUILDER or SOURCE
#           The point here is that this is where the asset
#           comes from.
FROM debian:bookworm-slim as builder

# The location of your desired assets in the source image.
WORKDIR /src

# Creating an example asset. But this might be a batch of
# angular files, as a random example. You could even zip
# them here.
RUN touch foo

# STEP TWO: Use the scratch image to isolate the desired
#           asset so that they can be exported.
FROM scratch AS assets

# Copy the asset(s) from the builder/source into scratch.
COPY --from=builder /src/foo /

ENTRYPOINT [ "/src" ]

# STEP THREE: Run a build cmd with the --output flag, like:
#             `docker build --output=foo --target=assets .`