chore: add dev container support for simplicity

.devcontainer/Dockerfile

@@ -0,0 +1,45 @@
+FROM ubuntu:24.04
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+# netplan dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    bash-completion \
+    build-essential \
+    cmake \
+    gcovr \
+    libcmocka-dev \
+    libglib2.0-dev \
+    libsystemd-dev \
+    libyaml-dev \
+    meson \
+    network-manager \
+    pandoc \
+    pkg-config \
+    pycodestyle \
+    pyflakes3 \
+    python3-cffi \
+    python3-coverage \
+    python3-dev \
+    python3-pytest \
+    python3-pytest-cov \
+    python3-yaml \
+    systemd \
+    udev \
+    uuid-dev \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+# devcontainer dependencies
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    git \
+    sudo \
+    && apt-get clean \
+    && rm -rf /var/lib/apt/lists/*
+
+RUN echo "ubuntu ALL=(ALL) NOPASSWD: ALL" > /etc/sudoers.d/ubuntu \
+    && chmod 0440 /etc/sudoers.d/ubuntu
+
+WORKDIR /workspace
+
+USER ubuntu

.devcontainer/devcontainer.json

@@ -0,0 +1,8 @@
+{
+  "name": "Netplan Development",
+  "build": {
+      "dockerfile": "Dockerfile",
+      "context": ".."
+    },
+  "remoteUser": "ubuntu"
+}

HACKING.md

@@ -0,0 +1,16 @@
+# Hacking Guide
+
+## Container Usage
+
+### VS Code Dev Container
+
+A devcontainer is provided under `.devcontainer/`.
+
+1. Install the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers).
+2. Open this repository in VS Code.
+3. Run `Dev Containers: Reopen in Container` from the Command Palette.
+
+## Notes
+
+- The Docker image is useful for reproducible builds and many tests.
+- Some system-level integration scenarios (for example, full network service lifecycle behavior) are better exercised VM-based environments.

README.md

@@ -39,9 +39,11 @@ To contribute documentation, these steps should get you started:
 
 If you face issues, refer to our [comprehensive contribution guide](https://netplan.readthedocs.io/en/stable/contribute-docs/).
 
+For development workflows (including VS Code container usage), see [HACKING.md](HACKING.md).
+
 # Build dependencies
 
-Install the required build and test dependencies (Ubuntu/Debian):
+For a manual setup without containers, install the required build and test dependencies:
 
 ```sh
 sudo apt install \
@@ -98,30 +100,30 @@ Convenience targets are available via `make`:
 - `make run ARGS='<command>'`  
   Run the locally built netplan CLI with the appropriate environment, for example, to run `netplan help`:
   ```sh
-  $ make run ARGS="help"
+  make run ARGS="help"
   ```
 
 # Test local build
 
 After running:
 
 ```sh
-$ make
-$ make install
+make
+make install
 ```
 
 the locally built `netplan` can be tested without installing it system-wide:
 
 ```sh
-$ make run ARGS="<command>"
+make run ARGS="<command>"
 ```
 
 This wrapper sets the required environment variables (such as `NETPLAN_GENERATE_PATH`) automatically. These are needed because the Python CLI resolves binary and library paths at runtime.
 
 As an example, let's use `make run` to run `netplan info`:
 
 ```sh
-$ make run ARGS="info"
+make run ARGS="info"
 # output:
 netplan.io:
   website: "https://netplan.io/"