Refactor Dockerfile and update dependency management for improved clarity; enhance README with dependency details and installation instructions

Dockerfile

@@ -3,10 +3,10 @@ SHELL ["/bin/bash", "-lc"]
 WORKDIR /ws
 
 # Install build dependencies
-COPY apt-requirements.txt /tmp/requirements.txt
+COPY apt-requirements.txt /tmp/apt-build.txt
 RUN apt-get update \
-  && xargs -a /tmp/requirements.txt apt-get install -y --no-install-recommends \
-  && rm -rf /var/lib/apt/lists/* /tmp/requirements.txt
+  && grep -Ev '^[[:space:]]*($|#)' /tmp/apt-build.txt | xargs apt-get install -y --no-install-recommends \
+  && rm -rf /var/lib/apt/lists/* /tmp/apt-build.txt
 
 # Copy package manifest and install rosdeps
 COPY package.xml ./package.xml
@@ -29,7 +29,7 @@ WORKDIR /ws
 ## Install minimal runtime packages required by the built binaries
 COPY apt-runtime.txt /tmp/apt-runtime.txt
 RUN apt-get update \
-  && xargs -a /tmp/apt-runtime.txt apt-get install -y --no-install-recommends \
+  && grep -Ev '^[[:space:]]*($|#)' /tmp/apt-runtime.txt | xargs apt-get install -y --no-install-recommends \
   && rm -rf /var/lib/apt/lists/* /tmp/apt-runtime.txt
 
 COPY --from=build /ws/install /ws/install

README.md

@@ -14,10 +14,34 @@ You are reading now the README for a **default** ROS2 package. If you want to us
 ## Dependencies
 - ROS2 Humble
 
+- Dependency files in this repository:
+  - `apt-requirements.txt`: build-only system dependencies.
+  - `apt-runtime.txt`: runtime system dependencies (minimal default set).
+  - `requirements.txt`: pip dependencies (currently none required).
+- OpenCV policy: use APT package `python3-opencv` (do not install `opencv-python` via pip by default).
+
+- Optional debug-only packages:
+  - `ros-humble-ros2cli`
+  - `net-tools`
+  - `iputils-ping`
+  - These are listed as commented entries in `apt-runtime.txt` and are not installed by default.
+
 - gstreamer libs:
 ```bash
 sudo apt-get install libgstreamer-plugins-base1.0-dev libgstreamer-plugins-good1.0-dev libgstreamer-plugins-bad1.0-dev libgstrtspserver-1.0-dev gstreamer1.0-plugins-ugly gstreamer1.0-plugins-bad
 ```
+
+For a minimal host setup using repository-managed lists:
+```bash
+sudo apt-get update
+grep -Ev '^[[:space:]]*($|#)' apt-requirements.txt | xargs sudo apt-get install -y --no-install-recommends
+grep -Ev '^[[:space:]]*($|#)' apt-runtime.txt | xargs sudo apt-get install -y --no-install-recommends
+```
+
+Install debug tools only when needed:
+```bash
+sudo apt-get install -y --no-install-recommends ros-humble-ros2cli net-tools iputils-ping
+```
 ## Install
   - Navigate to the root directory, create a new directory named `ros2_ws/src`, and then change the current working directory to `ros2_ws/src`:
       ```bashrc

apt-requirements.txt

@@ -3,12 +3,12 @@ build-essential
 cmake
 pkg-config
 libopencv-dev
-python3-opencv
 python3-rosdep
 python3-rosdistro
 software-properties-common
 libgstreamer1.0-dev
 libgstreamer-plugins-base1.0-dev
+libgstreamer-plugins-bad1.0-dev
 libgstreamer-plugins-good1.0-dev
 libgstrtspserver-1.0-dev
 ninja-build

apt-runtime.txt

@@ -5,7 +5,10 @@ gstreamer1.0-plugins-bad
 gstreamer1.0-plugins-ugly
 libgstrtspserver-1.0-0
 python3-opencv
-ros-humble-ros2cli
 ros-humble-rclpy
-net-tools
-iputils-ping
+
+# Optional debug-only tools (not required for normal runtime)
+# Uncomment/install manually only when troubleshooting:
+# ros-humble-ros2cli
+# net-tools
+# iputils-ping

docker-compose.yml

@@ -16,7 +16,8 @@ services:
     # Ensure the node binds to non-localhost interface (disable local_only)
     # and subscribe to the actual image topic available on the host
 
-    command: ["image2rtsp.launch.py", "local_only:=false", "topic:=/camera/image", "log_level:=debug"]
+    #log_level:= info, debug, warning, error, fatal
+    command: ["image2rtsp.launch.py", "local_only:=false", "topic:=/camera/image", "log_level:=info"]
 
 
     restart: unless-stopped

requirements.txt

@@ -1 +1,2 @@
-opencv-python
+# No required pip dependencies.
+# OpenCV is provided via apt package: python3-opencv.