build-texpresso

#!/bin/bash

# ─────────────────────────────────────────────────────────────────────────────
#
# TeXpresso Build Script
# ======================
#
# Overview
# --------
#
# The **TeXpresso Build Script** is a Bash script designed to automate the
# building of the [TeXpresso](https://github.com/let-def/texpresso) project
# using Docker. This script sets up a clean build environment, compiles the
# necessary binaries, and retrieves them to your local machine. By leveraging
# Docker, the script ensures consistency across different systems and
# simplifies the build process.
#
# Features
# --------
#
# - **Automated Docker Environment Setup**: Configures a Docker container with
#   all required dependencies for building TeXpresso.
# - **Multi-Stage Docker Build**: Utilizes Docker's multi-stage build to
#   optimize the build process and reduce final image size.
# - **Binary Extraction**: Automatically retrieves the compiled binaries
#   (`texpresso` and `texpresso-tonic`) from the Docker container to your
#   current directory.
# - **Cleanup**: Removes temporary build directories and prunes unused Docker
#   resources to keep your system clean.
# - **User-Friendly**: Ensures proper permissions are set for the extracted
#   binaries, making them ready for immediate use.
#
# Prerequisites
# -------------
#
# Before running the script, ensure that your system meets the following
# requirements:
#
# - **Operating System**: Linux-based system.
# - **Root Privileges**: The script must be run with root privileges.
# - **Docker Installed**: Docker must be installed and running on your system.
#
# Usage
# -----
#
# Run the script with root privileges:
#
# ```
# bash sudo ./build_texpresso.sh
# ```
#
# What the Script Does
# --------------------
#
# 1. **Privilege Check**: Verifies that the script is executed as the root
#    user.
# 2. **Docker Status Check**: Confirms that Docker is installed and the
#    Docker daemon is running.
# 3. **Temporary Build Directory**: Creates a temporary directory for the build
#    process, ensuring that temporary files do not clutter your system.
# 4. **Dockerfile Creation**: Generates a Dockerfile with two stages:
#    - **Builder Stage**:
#      - Based on Debian 12.
#      - Installs necessary build dependencies.
#      - Sets up Rust using `rustup`.
#      - Clones the TeXpresso repository and its submodules.
#      - Compiles the TeXpresso project.
#    - **Extractor Stage**:
#      - Also based on Debian 12.
#      - Copies the compiled binaries from the builder stage.
# 5. **Docker Image Build**: Builds the Docker image named `texpresso-debian`
#    using the generated Dockerfile.
# 6. **Docker Container Run**: Runs a container from the `texpresso-debian`
#    image.
# 7. **Binary Extraction**: Copies the `texpresso` and `texpresso-tonic`
#    binaries from the Docker container to the current working directory.
# 8. **Cleanup**:
#    - Stops the Docker container.
#    - Removes temporary build directories.
#    - Prunes unused Docker images and resources.
# 9. **Permission Adjustment**: Changes the ownership of the extracted binaries
#    to the original non-root user.
#
# After Running the Script
# ------------------------
#
# Upon successful execution, you will find the `texpresso` and
# `texpresso-tonic` binaries in your current directory with appropriate
# permissions.
#
# License
# -------
#
# This script is licensed under the WTFPL License
#
# ─────────────────────────────────────────────────────────────────────────────

set -eu

# This scipt uses docker and must be run as root
if [ "$EUID" -ne 0 ]
  then echo "Please run as root"
  exit 1
fi

# Check that docker is running
if ! docker info > /dev/null 2>&1; then
  echo "This script uses docker, and it isn't running - please start docker and try again!"
  exit 1
fi

# Store current directory in a variable
CURRENT_DIR=$(pwd)

# Create a temporary build directory
BUILD_DIR=$(mktemp -d "${TMPDIR:-/tmp}/build-texpresso.XXXXXXXX")
trap 'rm -rf "$BUILD_DIR"' EXIT

# Create the Dockerfile
cat > "$BUILD_DIR/Dockerfile" << 'EOL'
# Stage 1: Build Stage
FROM debian:12 AS builder

# Set environment variables
ENV DEBIAN_FRONTEND=noninteractive
ENV USER=texpresso
ENV PATH="/home/${USER}/.cargo/bin:${PATH}"

# Update and install necessary dependencies
RUN apt-get update && apt-get install -y \
    build-essential \
    libsdl2-dev \
    libmupdf-dev \
    libfreetype-dev \
    libjpeg-dev \
    libjbig2dec0-dev \
    libharfbuzz-dev \
    libopenjp2-7-dev \
    libgumbo-dev \
    libmujs-dev \
    libssl-dev \
    libfontconfig-dev \
    curl \
    git \
    bash \
    && rm -rf /var/lib/apt/lists/*

# Create a new user for TeXpresso and create the directory with proper permissions
RUN useradd -ms /bin/bash $USER && mkdir /texpresso-bin && chown $USER:$USER /texpresso-bin

# Switch to the newly created user
USER $USER
WORKDIR /home/$USER

# Install rustup and set up the latest Rust version as the texpresso user
RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | bash -s -- -y

# Clone the TeXpresso repository
RUN git clone --recurse-submodules https://github.com/let-def/texpresso.git
WORKDIR /home/$USER/texpresso

# Update Rust dependencies in the tectonic submodule to avoid version conflicts
RUN /bin/bash -c "source $HOME/.cargo/env && cd tectonic && cargo update"

# Build TeXpresso
RUN /bin/bash -c "source $HOME/.cargo/env && make all"

# Stage 2: Extraction Stage
FROM debian:12 AS extractor

# Create a directory to hold the binary
RUN mkdir /texpresso-bin

# Copy the built binary from the builder stage
COPY --from=builder /home/texpresso/texpresso/build/texpresso /texpresso-bin/
COPY --from=builder /home/texpresso/texpresso/build/texpresso-tonic /texpresso-bin/
EOL

# Build the docker image
docker build -t texpresso-debian "$BUILD_DIR"

# Run a docker image from the newly created image
docker run --name texpresso-debian texpresso-debian

# Copy the binary from the docker image to the current directory
docker cp texpresso-debian:/texpresso-bin/texpresso $CURRENT_DIR/
docker cp texpresso-debian:/texpresso-bin/texpresso-tonic $CURRENT_DIR/

# Stop the docker container
docker stop texpresso-debian

# Remove unused docker build images
docker system prune -f

# Change ownership of the binary files
chown $SUDO_USER:$SUDO_USER $CURRENT_DIR/texpresso $CURRENT_DIR/texpresso-tonic