# set app name
ARG app=roulette

# create build stage
ARG TAG
FROM --platform=$BUILDPLATFORM golang:$TAG AS build
ARG app

# copy source files into the container
COPY . /src/$app/

# build the binary
WORKDIR /src/$app
ARG TARGETOS TARGETARCH
RUN CGO_ENABLED=0 \
    GOOS=$TARGETOS \
    GOARCH=$TARGETARCH \
    go build -trimpath -tags timetzdata -o $app \
    && chmod 500 $app

# set up final stage
FROM --platform=$BUILDPLATFORM alpine:latest
ARG app

# copy in user info
COPY --chown=root:root --chmod=0400 docker/passwd /etc/passwd

# run as root for debug
USER root

# copy in binary
COPY --from=build --chown=root:root --chmod=0005 /src/$app/$app /$app

# listen on an unprivileged port
EXPOSE 8080

# launch a shell by default
ENTRYPOINT ["/bin/ash"]