FROM --platform=$BUILDPLATFORM golang:1.26-alpine as builder

ARG TARGETOS=linux
ARG TARGETARCH
ARG TARGETVARIANT

RUN mkdir /build
COPY . /build/
WORKDIR /build
RUN set -eux; \
    GOARM="${TARGETVARIANT#v}"; \
    CGO_ENABLED=0 GOOS="${TARGETOS}" GOARCH="${TARGETARCH}" GOARM="${GOARM}" go build -o invertergui ./cmd/invertergui

FROM scratch

# Group ID 20 is dialout, needed for tty read/write access
USER 3000:20
ENV READ_ONLY=false
COPY --from=builder /build/invertergui /bin/
ENTRYPOINT [ "/bin/invertergui" ]
EXPOSE 8080