Dockerfile

# Find eligible builder and runner images on Docker Hub. We use Ubuntu/Debian
# instead of Alpine to avoid DNS resolution issues in production.
#
# https://hub.docker.com/r/hexpm/elixir/tags?name=ubuntu
# https://hub.docker.com/_/ubuntu/tags
#
# This file is based on these images:
#
#   - https://hub.docker.com/r/hexpm/elixir/tags - for the build image
#   - https://hub.docker.com/_/debian/tags?name=bookworm-20251020-slim - for the release image
#   - https://pkgs.org/ - resource for finding needed packages
#   - Ex: docker.io/hexpm/elixir:1.17.3-erlang-26.2.4-debian-bookworm-20251020-slim
#
ARG ELIXIR_VERSION=1.17.3
ARG OTP_VERSION=26.2.4
ARG DEBIAN_VERSION=bookworm-20251020-slim

ARG BUILDER_IMAGE="docker.io/hexpm/elixir:${ELIXIR_VERSION}-erlang-${OTP_VERSION}-debian-${DEBIAN_VERSION}"
ARG RUNNER_IMAGE="docker.io/debian:${DEBIAN_VERSION}"

FROM ${BUILDER_IMAGE} AS builder

# install build dependencies (including Node.js for npm, brotli for compression, and Rust for NIFs)
RUN apt-get update \
  && apt-get install -y --no-install-recommends build-essential git curl brotli \
  && curl -fsSL https://deb.nodesource.com/setup_20.x | bash - \
  && apt-get install -y nodejs \
  && rm -rf /var/lib/apt/lists/*

# Install Rust for building NIFs from source (ex_keccak, ex_secp256k1)
RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
ENV PATH="/root/.cargo/bin:${PATH}"

# Force building Rust NIFs from source (GitHub release assets often blocked from CI)
ENV EX_KECCAK_BUILD="1"
ENV RUSTLER_BUILD="1"
ENV AUTUMN_BUILD="1"
ENV MDEX_BUILD="1"
ENV LUMIS_BUILD="1"
ENV RESVG_BUILD="1"

# resvg's crate pins lto=true and codegen-units=1, which costs several minutes
# on a shared builder for no runtime benefit at this image size.
ENV CARGO_PROFILE_RELEASE_LTO="off"
ENV CARGO_PROFILE_RELEASE_CODEGEN_UNITS="16"

# prepare build dir
WORKDIR /app

# install hex + rebar
RUN mix local.hex --force \
  && mix local.rebar --force

# set build ENV
ENV MIX_ENV="prod"

# install mix dependencies
COPY mix.exs mix.lock ./
RUN mix deps.get --only $MIX_ENV
RUN mkdir config

# copy compile-time config files before we compile dependencies
# to ensure any relevant config change will trigger the dependencies
# to be re-compiled.
COPY config/config.exs config/${MIX_ENV}.exs config/
RUN mix deps.compile

# Copy package files for npm dependency installation (better Docker layer caching)
COPY assets/package.json assets/package-lock.json ./assets/

# Install npm dependencies (requires package.json, package-lock.json)
RUN mix assets.setup

# Copy rest of assets after npm install
COPY assets ./assets

COPY priv priv

COPY lib lib

# Compile the release
RUN mix compile

# compile assets
RUN mix assets.deploy

# Changes to config/runtime.exs don't require recompiling the code
COPY config/runtime.exs config/

COPY rel rel
RUN mix release

# start a new build stage so that the final image will only contain
# the compiled release and other runtime necessities
FROM ${RUNNER_IMAGE} AS final

RUN apt-get update \
  && apt-get install -y --no-install-recommends \
    libstdc++6 openssl libncurses5 locales ca-certificates \
    chromium chromium-sandbox \
    poppler-utils \
    iptables iproute2 wget \
  && rm -rf /var/lib/apt/lists/*

# Install Tailscale (TUN mode reaches MinIO at 100.117.205.87 on the tailnet)
ARG TAILSCALE_VERSION=1.98.3
RUN wget --quiet "https://pkgs.tailscale.com/stable/tailscale_${TAILSCALE_VERSION}_amd64.tgz" -O /tmp/ts.tgz \
  && tar xzf /tmp/ts.tgz -C /usr/local/bin --strip-components=1 \
       "tailscale_${TAILSCALE_VERSION}_amd64/tailscale" \
       "tailscale_${TAILSCALE_VERSION}_amd64/tailscaled" \
  && rm /tmp/ts.tgz \
  && mkdir -p /var/run/tailscale /var/cache/tailscale /var/lib/tailscale

# Set the locale
RUN sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen \
  && locale-gen

ENV LANG=en_US.UTF-8
ENV LANGUAGE=en_US:en
ENV LC_ALL=en_US.UTF-8

WORKDIR "/app"
RUN chown nobody /app

# set runner ENV
ENV MIX_ENV="prod"

# Only copy the final release from the build stage
COPY --from=builder /app/_build/${MIX_ENV}/rel/droodotfoo ./

# Copy Fly entrypoint (starts tailscaled before the app)
COPY rel/start-fly.sh /app/start-fly.sh
RUN chmod +x /app/start-fly.sh

# Run as root so tailscaled can manage TUN/iptables. Fly's container
# isolation handles the security boundary.

# If using an environment that doesn't automatically reap zombie processes, it is
# advised to add an init process such as tini via `apt-get install`
# above and adding an entrypoint. See https://github.com/krallin/tini for details
# ENTRYPOINT ["/tini", "--"]

CMD ["/app/start-fly.sh"]