Add config for setting custom Chromium path

Also update SETUP/README with instructions

SETUP.md

@@ -9,18 +9,26 @@
 # Initial setup
 ## Puppeteer module
 1. Download a .crx or .zip file of the [LINE Chrome extension](https://chrome.google.com/webstore/detail/line/ophjlpahpchlmihnnnihgmmeilfjmjjc) (current version: 2.4.5)
-    * The recommended way of doing this is with the [CRX Extractor/Downloader](https://chrome.google.com/webstore/detail/crx-extractordownloader/ajkhmmldknmfjnmeedkbkkojgobmljda) extension for Chrome/Chromium. Simply install that extension in a Chrome/Chromium instance of your choice, then navigate to the Web Store page for the LINE extension, click the "CRX" button in the toolbar, and select "Download as ZIP"
-1. Extract the downloaded .crx file to `puppet/extension_files`
+    * The recommended way of doing this is with the [CRX Extractor/Downloader](https://chrome.google.com/webstore/detail/crx-extractordownloader/ajkhmmldknmfjnmeedkbkkojgobmljda) extension for Chrome/Chromium:
+        1. Install that extension in a Chrome/Chromium instance of your choice
+        2. Navigate to the Web Store page for the LINE extension
+        3. Click the "CRX" button in the browser toolbar
+        4. Select "Download as CRX" or "Download as ZIP"
+1. Extract the downloaded .crx/.zip file to `puppet/extension_files`
     * This can be done with `unzip <*.crx|*.zip> -d puppet/extension_files`, or with a GUI tool like GNOME File Roller
 1. `cd` to the `puppet` directory and run `yarn --production`
-1. Run `node prep_helper.js` to open the version of Chrome downloaded by Puppeteer, and click on the LINE icon next to the URL bar
+1. Copy `puppet/example-config.json` to `puppet/config.json`
+1. If your system's CPU architecture is not x86\_64, the version of Chromium bundled with Puppeteer will not work, and the following steps are required:
+    1. Install Chrome/Chromium from your distribution's package manager
+    1. Set `executable_path` in `puppet/config.json` to the path to the installed Chrome/Chromium binary
+1. Run `node prep_helper.js` to open Chrome/Chromium with the downloaded LINE extension enabled, and click on the LINE icon next to the URL bar
 1. Once the LINE popup appears, press F12 to show DevTools, which will reveal the LINE extension's UUID
-1. Copy `puppet/example-config.json` to `puppet/config.json`, and set some important settings:
+1. Edit `puppet/config.json` with some important settings:
     * set `"url"` to the UUID found in the previous step
     * set the `"listen"` settings to the socket to use for communication with the bridge (see [puppet/README.md](puppet/README.md) for details)
 
 ## Bridge
-1. `cd` to the project root directory and create a Python virtual environment with `python -m venv .venv`, and enter it with `source .venv/bin/activate`
+1. `cd` to the project root directory and create a Python virtual environment with `python3 -m venv .venv`, and enter it with `source .venv/bin/activate`
 1. Install Python requirements:
     * `pip install -Ur requirements.txt` for base functionality
     * `pip install -Ur optional_requirements.txt` for [end-to-bridge](https://docs.mau.fi/bridges/general/end-to-bridge-encryption.html) encryption and metrics
@@ -34,7 +42,7 @@
 1. Start a chat with the bot and follow the instructions
 
 # Running the Puppeteer module headless
-Puppeteer cannot be run in headless mode when using Chromium with extensions (including the LINE extension).
+Puppeteer cannot be run in headless mode when using Chrome/Chromium with extensions (including the LINE extension).
 
 As a workaround, it may be run in a background X server. This allows running the Puppeteer module on a GUI-less server.
 

puppet/README.md

@@ -3,6 +3,9 @@ If `type` is `unix`, `path` is the path where to create the socket.
 
 If `type` is `tcp`, `port` and `host` are the host/port where to listen.
 
+### Executable path
+The `executable_path` specifies the path to the Chromium binary for Puppeteer to use. Leaving this setting blank will use the x86_64 Chromium installation bundled with Puppeteer. For other architectures, it is necessary to install a compatible version of Chromium (ideally via your distribution's package manager), and to set `executable_path` to the path of its binary (typically `/usr/bin/chromium`).
+
 ### Profile directory
 The `profile_dir` specifies which directory to put Chromium user data directories.
 

puppet/example-config.json

@@ -3,6 +3,7 @@
 		"type": "unix",
 		"path": "/var/run/matrix-puppeteer-line/puppet.sock"
 	},
+	"executable_path": "",
 	"profile_dir": "./profiles",
 	"url": "chrome-extension://<extension-uuid>/index.html",
 	"extension_dir": "./extension_files",

puppet/prep_helper.js

@@ -1,13 +1,45 @@
+// matrix-puppeteer-line - A very hacky Matrix-LINE bridge based on running LINE's Chrome extension in Puppeteer
+// Copyright (C) 2020-2021 Tulir Asokan, Andrew Ferrazzutti
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
 import puppeteer from "puppeteer"
+import fs from "fs"
+
+import arg from "arg"
+
+const args = arg({
+	"--config": String,
+	"--browser": String,
+	"-c": "--config",
+	"-b": "--browser",
+})
+
+const configPath = args["--config"] || "config.json"
+
+console.log("[Main] Reading config from", configPath)
+const config = JSON.parse(fs.readFileSync(configPath).toString())
+const extensionDir = config.extension_dir || "extension_files"
+const executablePath = args["--browser"] || config.executable_path;
 
 (async () =>
 {
-    const pathToExtension = "extension_files"
-    const browser = await puppeteer.launch({
+	await puppeteer.launch({
+		executablePath: executablePath,
 		headless: false,
 		args: [
-            `--disable-extensions-except=${pathToExtension}`,
-            `--load-extension=${pathToExtension}`
+				`--disable-extensions-except=${extensionDir}`,
+			`--load-extension=${extensionDir}`
 		],
 		timeout: 0,
     })

puppet/src/main.js

@@ -30,11 +30,11 @@ const args = arg({
 })
 
 const configPath = args["--config"] || "config.json"
-MessagesPuppeteer.executablePath = args["--browser"] || MessagesPuppeteer.executablePath
-MessagesPuppeteer.noSandbox = args["--no-sandbox"]
 
 console.log("[Main] Reading config from", configPath)
 const config = JSON.parse(fs.readFileSync(configPath).toString())
+MessagesPuppeteer.executablePath = args["--browser"] || config.executable_path || MessagesPuppeteer.executablePath
+MessagesPuppeteer.noSandbox = args["--no-sandbox"] || MessagesPuppeteer.noSandbox
 MessagesPuppeteer.profileDir = config.profile_dir || MessagesPuppeteer.profileDir
 MessagesPuppeteer.devtools = config.devtools || false
 MessagesPuppeteer.url = config.url