Script python library builds, update documentation and dependencies (#…

…4640)

* Simplify python environment configuration:

- Add a build script that includes all of:
  - compile host python library
  - creates a virtual environment to use
  - installs WHL chip file

- Updated instructions for building - sudo should not be required for
installation (only running) and we should recommend virtual environment
usage due to the requirement to clean the package

- Added dependency to pygobject and six, removed dependency on pgi

* Restyle fixes

* Minor update to kick the restyle checker in github

* Use `realpath` to output nicer paths and not use .. thoughout

* Restyle fixes

* Add instruction to ask for Ubuntu 20.10 instead of 20.04 for Raspberry pi

* Restyle fixes

docs/BUILDING.md

@@ -71,8 +71,9 @@ dependency.
 
 #### How to install prerequisites on Raspberry Pi 4
 
-Using `rpi-imager`, install the Ubuntu 20.04.1 LTS (Raspberry Pi 3/4) 64-bit
-server OS for arm64 architectures on a micro SD card.
+Using `rpi-imager`, install the Ubuntu _20.10_ LTS 64-bit _server_ OS for arm64
+architectures on a micro SD card. This release will have bluez 5.55 which is
+required for BLE functionality.
 
 Boot the SD card, login with the default user account "ubuntu" and password
 "ubuntu", then proceed with "How to install prerequisites on Linux".

scripts/build_python.sh

@@ -0,0 +1,61 @@
+#!/usr/bin/env bash
+
+#
+# Copyright (c) 2021 Project CHIP Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+set -e
+
+echo_green() {
+    echo -e "\033[0;32m$*\033[0m"
+}
+
+echo_blue() {
+    echo -e "\033[1;34m$*\033[0m"
+}
+
+echo_bold_white() {
+    echo -e "\033[1;37m$*\033[0m"
+}
+
+CHIP_ROOT=$(realpath "$(dirname "$0")/..")
+OUTPUT_ROOT="$CHIP_ROOT/out/python_lib"
+ENVIRONMENT_ROOT="$CHIP_ROOT/out/python_env"
+
+# Ensure we have a compilation environment
+source "$CHIP_ROOT/scripts/activate.sh"
+
+# Generates ninja files
+gn --root="$CHIP_ROOT" gen "$OUTPUT_ROOT"
+
+# Compiles python files
+ninja -C "$OUTPUT_ROOT" python
+
+# Create a virtual environment that has access to the built python tools
+virtualenv --clear "$ENVIRONMENT_ROOT"
+
+# Activate the new enviroment to register the python WHL
+source "$ENVIRONMENT_ROOT"/bin/activate
+"$ENVIRONMENT_ROOT"/bin/python -m pip install --upgrade pip
+"$ENVIRONMENT_ROOT"/bin/pip install "$OUTPUT_ROOT"/controller/python/chip-*.whl
+
+RELATIVE_ENVIRONMENT_ROOT=$(realpath --relative-to "$PWD" "$ENVIRONMENT_ROOT")
+
+echo ""
+echo_green "Compilation completed and WHL package installed in: "
+echo_blue "  $RELATIVE_ENVIRONMENT_ROOT"
+echo ""
+echo_green "To use please run:"
+echo_bold_white "  source $RELATIVE_ENVIRONMENT_ROOT/bin/activate"

src/controller/python/README.md

@@ -17,31 +17,40 @@ focus on its python binding interface on Linux and mac os.
 git clone https://github.com/project-chip/connectedhomeip.git
 ```
 
-2. Build CHIP
+2. Build the CHIP python package
 
-Follow [BUILDING.md](/docs/BUILDING.md) to build CHIP on your platform.
+Follow [BUILDING.md](/docs/BUILDING.md) to setup CHIP on your platform.
+
+Genrally, once build dependencies are satisfied you can build the `python`
+target.
+
+Use `scripts/build_python.sh` or run something equivalent to:
+
+```sh
+gn gen out/python_lib
+ninja -C out/python_lib python
+```
 
 3. Install Chip Device Controller
 
 > Note: Python device controller is not versioned, so you need to uninstall the
 > old device controller before install the new one.
 
-**For Linux (Raspberry Pi 4)**
+> It is recommended to setup a separate clean virtual environment The
+> `scripts/build_python.sh` script sets up a python environment and installs the
+> WHL file.
 
-```
-cd out/debug/controller/python
-sudo pip3 install chip-0.0-cp38-cp38-linux_aarch64.whl
+```sh
+virtualenv out/python_env --clean
+source out/python_env/bin/activate
+pip install out/python_lib/controller/python/chip*.whl
 ```
 
-> Note: for linux, sudo is necessary since it need to interact with bluetoothd
-> via dbus with sudo permission
+The WHL file installation will:
 
-**For macOS**
-
-```
-cd out/debug/mac_x64_clang/controller/python
-pip3 install chip-0.0-cp38-cp38-mac_aarch64.whl
-```
+-   Install the 'chip' module
+-   create a `ENV/bin/chip-device-ctrl` script that provides an interactive
+    shell for the chip library
 
 ## BLE Virtualization on Linux (Optional)
 
@@ -78,6 +87,9 @@ sudo third_party/bluez/repo/emulator/btvirt -L -l2
 
 1. Run CHIP Device Controller
 
+> Running as root via `sudo` to ensure permissions to interface with the
+> bluetooth adapter.
+
 ```
 sudo chip-device-ctrl
 ```

src/controller/python/build-chip-wheel.py

@@ -99,7 +99,8 @@ def finalize_options(self):
     if platform.system() == 'Linux':
         requiredPackages = [
             'dbus-python',
-            'pgi'
+            'six',
+            'pygobject',
         ]
     else:
         requiredPackages = []