Multi-stage Dockerfile with multiple targets for gooder life

Dockerfile

FROM golang:1.16-buster AS builder
WORKDIR /src
COPY go.mod go.sum ./
RUN go mod download
COPY . .
RUN go build ./cmd/director && \
    go build ./cmd/frontend && \
    go build ./cmd/matchfunction

FROM gcr.io/distroless/base-debian10 AS director
COPY --from=builder /src/director /
ENTRYPOINT ["/director"]

FROM gcr.io/distroless/base-debian10 AS frontend
COPY --from=builder /src/frontend /
ENTRYPOINT ["/frontend"]

FROM gcr.io/distroless/base-debian10 AS matchfunction
COPY --from=builder /src/matchfunction /
ENTRYPOINT ["/matchfunction"]

FROM builder AS test
RUN go test -v ./...