---
title: 【軟體】利用 Multi-Stage Builds 節省容量
tags: TTennis Pickup Robot
disqus: hackmd
---

<h1 style="text-align: center; color: orange;">
🛠️ 【軟體】必學的 Docker 🛠️
</h1>

<h2 style="text-align: center; color: skyblue;">利用 Multi-Stage Builds 節省容量</h2>

<center>

蠻多安裝依賴項目，官方會提供兩種安裝方式，
「Install binary files」或「Build from source」。

選擇「Build from source」代表要自己下載源文件並在本地編譯。
但在過程中的編譯環境、工具，在之後的部署階段可能是不需要的。

這時就是 Multi-Stage Build 的登場時機。

:::info
Multi-Stage Builds 理念是使用多個 stage 來構建 Image。
並拷貝前面階段編譯的二進制文件至後續階段。
:::

即便毋須降低容量，用 Multi-Stage Build 的概念來寫也會比較整潔。
</center>

</br>
<h3><font color ="magenza"> 1. 實際範例</font></h3>

:::success
整段示範代碼的邏輯：

1. 先以 **tools 階段**為基礎新增 **depthai-builder 階段**，去處理編譯問題。
2. 再同樣以 **tools** 為基礎構建 **final 階段**，並 copy **depthai-build** 的二進制文件。
:::

* **多階段構建 depthai-core**
* `FROM A AS B`：從 Image A 或階段 A 為基礎，開始構建階段 B。

	################################################################################################
	# - DepthAI Core Build Stage
	#   - In this stage, we will build DepthAI Core and extract necessary binary files.
	################################################################################################
	FROM tools AS depthai-builder

	## 安裝只有編譯期間才需要的工具
	RUN DEBIAN_FRONTEND=noninteractive apt-get update && \
		DEBIAN_FRONTEND=noninteractive apt-get install -y \
		cmake \
		libclang-dev \
		libssl-dev \
		patchelf \
		&& rm -rf /var/lib/apt/lists/*

	## 這裡下載源代碼並進行編譯
	RUN git clone https://github.com/luxonis/depthai-core.git && \
		cd depthai-core && \
		git submodule update --init --recursive && \
		mkdir -p build && cd build && \
		cmake .. && \ 
		cmake --build . --parallel $(nproc) && \
		cmake --install . --prefix /usr/local && \
		cd .. && cmake -S. -Bbuild -D'DEPTHAI_BUILD_EXAMPLES=ON' && \
		cmake --build build

	################################################################################################
	# - Final Stage
	#   - In this stage, we will install necessary packages and copy DepthAI Core binary files.
	################################################################################################
	FROM tools AS final

	## 只 copy 編譯後的二進制文件
	COPY --from=depthai-builder /usr/local/lib/libdepthai-core.so* /usr/local/lib/
	COPY --from=depthai-builder /usr/local/include/depthai /usr/local/include/depthai
	COPY --from=depthai-builder /usr/local/lib/cmake/depthai /usr/local/lib/cmake/depthai
	
	# ...

* **平常我就習慣用多階段構建的概念寫 Dockerfile**
* 參考範例 RTAB-Map

		################################################################################################
		# - Base stage
		#   - This stage serves as the foundational stage for all other stages.
		#   - Base image: OSRF ROS Humble Desktop Full
		#       - https://hub.docker.com/r/osrf/ros/tags?page=1&name=humble-desktop-full
		################################################################################################

		FROM osrf/ros:humble-desktop-full AS base

		LABEL org.opencontainers.image.authors="[e-mail]"

		ARG USERNAME=user
		ARG USER_UID=1000
		ARG USER_GID=$USER_UID

		SHELL ["/bin/bash", "-c"]


		################################################################################################
		# - User Setup stage
		#   - In this stage, I will create a non-root user and configure passwordless sudo.
		################################################################################################

		FROM base AS user-setup

		## Create a non-root user
		RUN groupadd --gid $USER_GID $USERNAME && \
			useradd --uid $USER_UID --gid $USER_GID -m $USERNAME -s /bin/bash && \
			apt-get update && \
			apt-get install -y sudo && \
			echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME && \
			chmod 0440 /etc/sudoers.d/$USERNAME && \
			rm -rf /var/lib/apt/lists/*


		################################################################################################
		# - Tools Installation stage
		#   - In this stage, I will install convenient tools for development.
		################################################################################################

		FROM user-setup AS tools

		## Install necessary packages
		RUN DEBIAN_FRONTEND=noninteractive apt-get update && \
			DEBIAN_FRONTEND=noninteractive apt-get install -y \
			apt-utils \
			git \
			nano \
			net-tools \
			ssh \
			usbutils \
			udev \ 
			x11-apps \ 
			&& rm -rf /var/lib/apt/lists/*


		################################################################################################
		# - Final stage
		#   - In this stage, I will install required packages for RTAB-Map and Intel RealSense.
		#   - Reference:
		#       - https://github.com/introlab/rtabmap_ros/tree/humble-devel?tab=readme-ov-file#installation
		#       - https://github.com/introlab/rtabmap_ros.git
		################################################################################################

		FROM tools AS final

		## Install Intel RealSense dependencies
		RUN DEBIAN_FRONTEND=noninteractive apt-get update && \
			DEBIAN_FRONTEND=noninteractive apt-get install -y \
			ros-humble-librealsense2* \
			ros-humble-realsense2-* && \
			rm -rf /var/lib/apt/lists/*

		## Install RTAB-Map dependencies
		RUN DEBIAN_FRONTEND=noninteractive apt-get update && \
			DEBIAN_FRONTEND=noninteractive apt-get install -y \
			ros-humble-rtabmap-ros && \
			rm -rf /var/lib/apt/lists/*

		## Install foxglove-bridge
		RUN DEBIAN_FRONTEND=noninteractive apt-get update && \
			DEBIAN_FRONTEND=noninteractive apt-get install -y \
			ros-humble-foxglove-bridge && \
			rm -rf /var/lib/apt/lists/*


		## Set working directory
		RUN echo "source /opt/ros/$ROS_DISTRO/setup.bash" >> ~/.bashrc
		WORKDIR /home/slam-ws

		## Final configurations
		# USER $USERNAME
		CMD ["/bin/bash"]