Example Dockerfile for static compilation of ReasonML / OCaml projects using esy.

Dockerfile.web

# vim: set filetype=dockerfile :
FROM node:10.13-alpine as build

ENV TERM=dumb \
    LD_LIBRARY_PATH=/usr/local/lib:/usr/lib:/lib

# Create a subuser so that NPM doesn't whine about running as root
RUN adduser -D -H -h /usr/src/app web && \
    mkdir -p /usr/src/app && \
    chown web:web /usr/src/app && \
    # Install dependencies
    apk add --no-cache \
      # Requirements for glibc
      ca-certificates wget \
      # Requirements for esy
      bash curl perl-utils \
      # Requirements for ocaml
      gcc musl-dev make m4 \
      # Requirements for bs-platform
      python g++ \
      # Requirements for my app
      git patch ncurses jq && \
    # esy is dynamically linked to glibc, not compiled locally. Oh well.
    wget -q -O /etc/apk/keys/sgerrand.rsa.pub https://alpine-pkgs.sgerrand.com/sgerrand.rsa.pub && \
    wget https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.28-r0/glibc-2.28-r0.apk && \
    apk add --no-cache glibc-2.28-r0.apk && \
    # --unsafe-perm because we want to install esy globally as root
    npm install -g --unsafe-perm @esy-nightly/esy@0.4.0-33b899

# Use the new user for the build
WORKDIR /usr/src/app
USER web

COPY --chown=web:web ./ ./
RUN npm install

# Force the backend to be built statically
RUN cd packages/backend && \
    esy build && \
    jq '.buildDirs.src.flags = ["-ccopt", "-static"]' package.json > package.json.new && \
    mv package.json.new package.json && \
    # Force pesy to understand that it is outside a build environment
    SHELL=sh esy pesy

# Build the application
RUN npm run build:production && \
    npm run build:aggregate

# This is the real magic. FROM scratch. Only the application lives here.
FROM scratch

ENV TERM=dumb \
    PORT=8080

COPY --from=build /usr/src/app/build /

CMD [ "/bin/BackendApp.exe" ]