pegasus/Dockerfile

# syntax=docker/dockerfile:1.7

############################
# Frontend build (Vite/React)
############################
# Run toolchains on the build machine, not target arch
FROM --platform=$BUILDPLATFORM node:20-alpine AS fe
WORKDIR /src/frontend
COPY frontend/package*.json ./
RUN --mount=type=cache,target=/root/.npm npm ci
COPY frontend/ .
RUN npm run build
# expose artifacts in a neutral location
RUN mkdir -p /out && cp -r dist/* /out/

############################
# Backend build (Go)
############################
FROM --platform=$BUILDPLATFORM golang:1.22-alpine AS be
RUN apk add --no-cache ca-certificates upx git
ARG TARGETOS
ARG TARGETARCH
ENV CGO_ENABLED=0 GOOS=${TARGETOS} GOARCH=${TARGETARCH} \
    GOPROXY=https://proxy.golang.org,direct \
    GOPRIVATE=scm.bstein.dev

WORKDIR /src/backend

# 1) Cache modules
COPY backend/go.mod backend/go.sum ./
RUN --mount=type=cache,target=/go/pkg/mod go mod download

# 2) Source
COPY backend/ .

# 3) FE assets where the embed expects them (//go:embed web/dist/**)
COPY --from=fe /out ./web/dist

# 4) Tidy (in case new deps appeared)
RUN --mount=type=cache,target=/go/pkg/mod go mod tidy

# 5) Build the binary; fail if build fails; allow UPX to fail only.
RUN --mount=type=cache,target=/go/pkg/mod \
    set -eux; \
    mkdir -p /out; \
    go build -trimpath -ldflags="-s -w" -o /out/pegasus ./main.go; \
    test -f /out/pegasus; \
    upx -q --lzma /out/pegasus || true

############################
# Final, minimal image
############################
FROM gcr.io/distroless/static:nonroot AS final
COPY --from=be /out/pegasus /pegasus
USER nonroot:nonroot
ENTRYPOINT ["/pegasus"]