Advanced

Custom Docker Images

All .go components get built using a default Docker image. If you want to use your own image, for example, because your component has custom dependencies, you can do that too.

One good example of such a component is the producers/ossf-scorecard component. Let's take a closer look at it.

In the below Dockerfile we using a custom base image and then are further configuring that.

dracon/components/producers/ossf-scorecard/Dockerfile

ARG OSSF_SCORECARD_SAFETY_BASE_IMAGE
FROM gcr.io/openssf/scorecard:stable

FROM ${OSSF_SCORECARD_SAFETY_BASE_IMAGE}

COPY --from=0 /scorecard /scorecard

ENTRYPOINT ["/scorecard"]

In addition, a Makefile is placed inside the component folder, to advice Smithy on how to build the component image.

dracon/components/producers/ossf-scorecard/Makefile

.PHONY: component publish

CONTAINER_REPO=
DRACON_VERSION=
OSSF_SCORECARD_SAFETY_BASE_IMAGE=$(shell test -e .custom_image && cat .custom_image || echo "alpine:latest")

DOCKER=docker

component:
	$(DOCKER) build --tag $(CONTAINER_REPO)/components/producers/ossf-scorecard:$(DRACON_VERSION) \
					--file Dockerfile \
					$$([ "${SOURCE_CODE_REPO}" != "" ] && echo "--label=org.opencontainers.image.source=${SOURCE_CODE_REPO}" ) \
					--build-arg OSSF_SCORECARD_SAFETY_BASE_IMAGE=$(OSSF_SCORECARD_SAFETY_BASE_IMAGE) ../../.. 1>&2

publish:
	$(DOCKER) push $(CONTAINER_REPO)/components/producers/ossf-scorecard:$(DRACON_VERSION) 1>&2

And that's it! Simply by adding these two files Smithy will now be able to build your component.