# Multi-service Dockerfile with build caching
# Usage: docker build --build-arg SERVICE=gateway -t cloud-gateway .

ARG SERVICE=gateway

# Build stage
FROM golang:1.24-alpine AS builder

RUN apk add --no-cache git ca-certificates

WORKDIR /src

# Cache dependencies first (changes less often)
COPY go.work go.work.sum* ./
COPY pkg/go.mod pkg/go.sum* ./pkg/
COPY services/${SERVICE}/go.mod services/${SERVICE}/go.sum* ./services/${SERVICE}/

RUN go mod download

# Copy source and build
COPY pkg/ ./pkg/
COPY services/${SERVICE}/ ./services/${SERVICE}/

WORKDIR /src/services/${SERVICE}
RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /app .

# Runtime stage
FROM alpine:3.20

RUN apk add --no-cache ca-certificates tzdata

COPY --from=builder /app /app

USER nobody:nobody
ENTRYPOINT ["/app"]