# syntax=docker/dockerfile:1.7

# Build context is the workspace root (galaxy/), not the game/ subdirectory,
# because the game module pulls galaxy/{calc,error,model,util} through the
# go.work replace directives. Build with:
#
#     docker build -t galaxy/game:test -f game/Dockerfile .

FROM golang:1.26.2-alpine AS builder
WORKDIR /src
ENV CGO_ENABLED=0 GOFLAGS=-trimpath

# Only the four pkg/ modules the engine binary actually imports.
COPY pkg/calc/   ./pkg/calc/
COPY pkg/error/  ./pkg/error/
COPY pkg/model/  ./pkg/model/
COPY pkg/util/   ./pkg/util/
COPY game/       ./game/

# Minimal workspace. The repository-level go.work also lists service
# modules (lobby, notification, ...) that the engine binary does not
# need, so we synthesise a workspace tailored to this image instead of
# dragging the rest of the monorepo into the build context.
RUN <<'EOF' cat > go.work
go 1.26.2

use (
	./game
	./pkg/calc
	./pkg/error
	./pkg/model
	./pkg/util
)

replace (
	galaxy/calc v0.0.0  => ./pkg/calc
	galaxy/error v0.0.0 => ./pkg/error
	galaxy/model v0.0.0 => ./pkg/model
	galaxy/util v0.0.0  => ./pkg/util
)
EOF

RUN --mount=type=cache,target=/root/.cache/go-build \
    --mount=type=cache,target=/go/pkg/mod \
    go build -ldflags="-s -w" -o /out/server ./game/cmd/http

FROM gcr.io/distroless/static-debian12:nonroot AS runtime

LABEL com.galaxy.cpu_quota="1.0"
LABEL com.galaxy.memory="512m"
LABEL com.galaxy.pids_limit="512"
LABEL org.opencontainers.image.title="galaxy-game-engine"

ENV STORAGE_PATH=/var/lib/galaxy-game
EXPOSE 8080
USER nonroot:nonroot

COPY --from=builder /out/server /usr/local/bin/server

ENTRYPOINT ["/usr/local/bin/server"]