Dockerfile.controller

# Build stage for the rpingmesh controller.
# CGO_ENABLED=0 — no RDMA or Zig dependencies needed.
FROM golang:1.26.0-bookworm AS builder

# Install protoc and Go protobuf plugins for code generation. This layer
# only depends on apt/Go tool versions, not application source, so it stays
# cached across source-only rebuilds.
RUN apt-get update && apt-get install -y --no-install-recommends \
        protobuf-compiler \
    && rm -rf /var/lib/apt/lists/* \
    && go install google.golang.org/protobuf/cmd/protoc-gen-go@latest \
    && go install google.golang.org/grpc/cmd/protoc-gen-go-grpc@latest

WORKDIR /app

# Copy module files first and resolve dependencies before copying the rest
# of the source tree, so `go mod download` is only re-run when go.mod/go.sum
# change (not on every source edit). go.sum is trusted as-is; it is expected
# to already be complete and committed (no `go mod tidy` in the container).
COPY go.mod go.sum ./
RUN --mount=type=cache,target=/go/pkg/mod \
    go mod download

# Copy remaining source and generate protobuf bindings.
COPY . .
RUN cd proto/controller_agent && \
    protoc --go_out=. --go_opt=paths=source_relative \
           --go-grpc_out=. --go-grpc_opt=paths=source_relative \
           controller_agent.proto

# Build the controller binary.
RUN --mount=type=cache,target=/go/pkg/mod \
    --mount=type=cache,target=/root/.cache/go-build \
    CGO_ENABLED=0 GOOS=linux go build -o /app/bin/rpingmesh-controller ./cmd/controller/

# Runtime image — minimal footprint.
FROM debian:bookworm-slim

RUN apt-get update && apt-get install -y --no-install-recommends \
        netcat-openbsd \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app
COPY --from=builder /app/bin/rpingmesh-controller ./rpingmesh-controller

EXPOSE 50051
ENTRYPOINT ["./rpingmesh-controller"]