support re-using already open browser window

README.md

@@ -10,6 +10,10 @@
 1. [About](#about)
 1. [Installation](#installation)
 1. [Usage](#usage)
+1. [Configuration](#config)
+   1. [Main configuration](#main-config)
+   1. [Ad configuration](#ad-config)
+   1. [Using an existing browser window](#existing-browser)
 1. [Development Notes](#development)
 1. [License](#license)
 
@@ -206,11 +210,11 @@ Options:
 
 Limitation of `download`: It's only possible to extract the cheapest given shipping option.
 
-### Configuration
+## <a name="config"></a>Configuration
 
 All configuration files can be in YAML or JSON format.
 
-#### 1) Main configuration
+### <a name="main-config"></a>1) Main configuration
 
 When executing the app it by default looks for a `config.yaml` file in the current directory. If it does not exist it will be created automatically.
 
@@ -271,7 +275,7 @@ login:
 
 ```
 
-#### 2) Ad configuration
+### <a name="ad-config"></a>2) Ad configuration
 
 Each ad is described in a separate JSON or YAML file with prefix `ad_<filename>`. The prefix is configurable in config file.
 
@@ -333,6 +337,30 @@ created_on: # set automatically
 updated_on: # set automatically
 ```
 
+### <a name="existing-browser"></a>3) Using an existing browser window
+
+By default a new browser process will be launched. To reuse a manually launched browser window/process follow these steps:
+
+1. Manually launch your browser from the command line with the `--remote-debugging-port=<NUMBER>` flag.
+   You are free to choose an unused port number 1025 and 65535, e.g.:
+   - `chrome --remote-debugging-port=9222`
+   - `chromium --remote-debugging-port=9222`
+   - `msedge --remote-debugging-port=9222`
+
+   This runs the browser in debug mode which allows it to be remote controlled by the bot.
+
+1. In your config.yaml specify the same flag as browser argument, e.g.:
+   ```yaml
+   browser:
+     arguments:
+     - --remote-debugging-port=9222
+   ```
+
+1. When now publishing ads the manually launched browser will be re-used.
+
+> NOTE: If an existing browser is used all other settings configured under `browser` in your config.yaml file will ignored
+  because they are only used to programmatically configure/launch a dedicated browser instance.
+
 ## <a name="development"></a>Development Notes
 
 > Please read [CONTRIBUTING.md](CONTRIBUTING.md) before contributing code. Thank you!
@@ -342,7 +370,7 @@ updated_on: # set automatically
   - unit tests: `pdm run utest`
   - integration tests: `pdm run itest`
   - all tests: `pdm run test`
-- Run linter: `pdm run lint`
+- Run syntax checks: `pdm run lint`
 - Create platform-specific executable: `pdm run compile`
 - Application bootstrap works like this:
   ```python

src/kleinanzeigen_bot/utils.py

@@ -3,7 +3,7 @@ SPDX-FileCopyrightText: © Sebastian Thomschke and contributors
 SPDX-License-Identifier: AGPL-3.0-or-later
 SPDX-ArtifactOfProjectHomePage: https://github.com/Second-Hand-Friends/kleinanzeigen-bot/
 """
-import asyncio, copy, decimal, json, logging, os, re, sys, traceback, time
+import asyncio, copy, decimal, json, logging, os, re, socket, sys, traceback, time
 from importlib.resources import read_text as get_resource_as_string
 from collections.abc import Callable, Sized
 from datetime import datetime
@@ -76,6 +76,18 @@ def is_integer(obj:Any) -> bool:
         return False
 
 
+def is_port_open(host:str, port:int) -> bool:
+    try:
+        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        s.settimeout(1)
+        s.connect((host, port))
+        return True
+    except Exception:
+        return False
+    finally:
+        s.close()
+
+
 async def ainput(prompt: str) -> str:
     return await asyncio.to_thread(input, f'{prompt} ')
 

src/kleinanzeigen_bot/web_scraping_mixin.py

@@ -18,7 +18,7 @@ from nodriver.core.config import Config
 from nodriver.core.element import Element
 from nodriver.core.tab import Tab as Page
 
-from .utils import ensure, T
+from .utils import ensure, is_port_open, T
 
 
 LOG:Final[logging.Logger] = logging.getLogger("kleinanzeigen_bot.selenium_mixin")
@@ -79,6 +79,35 @@ class WebScrapingMixin:
             self.browser_config.binary_location = self.get_compatible_browser()
         LOG.info(" -> Chrome binary location: %s", self.browser_config.binary_location)
 
+        ########################################################
+        # check if an existing browser instance shall be used...
+        ########################################################
+        remote_host = "127.0.0.1"
+        remote_port = 0
+        for arg in self.browser_config.arguments:
+            if arg.startswith("--remote-debugging-host="):
+                remote_host = arg.split("=", 2)[1]
+            if arg.startswith("--remote-debugging-port="):
+                remote_port = int(arg.split("=", 2)[1])
+
+        if remote_port > 0:
+            LOG.info("Using existing browser process at %s:%s", remote_host, remote_port)
+            if not is_port_open(remote_host, remote_port):
+                raise AssertionError(f"Browser process not reachable at {remote_host}:{remote_port}. "
+                        + f"Start the browser with --remote-debugging-port={remote_port} or remove this port from your config.yaml")
+            cfg = Config(
+                browser_executable_path = self.browser_config.binary_location  # actually not necessary but nodriver fails without
+            )
+            cfg.host = remote_host
+            cfg.port = remote_port
+            self.browser = await nodriver.start(cfg)
+            LOG.info("New Browser session is %s", self.browser.websocket_url)
+            return
+
+        ########################################################
+        # configure and initialize new browser instance...
+        ########################################################
+
         # default_browser_args: @ https://github.com/ultrafunkamsterdam/nodriver/blob/main/nodriver/core/config.py
         # https://peter.sh/experiments/chromium-command-line-switches/
         # https://github.com/GoogleChrome/chrome-launcher/blob/main/docs/chrome-flags-for-tools.md
@@ -125,6 +154,7 @@ class WebScrapingMixin:
             browser_args = browser_args,
             user_data_dir = self.browser_config.user_data_dir
         )
+
         # already logged by nodriver:
         # LOG.debug("-> Effective browser arguments: \n\t\t%s", "\n\t\t".join(cfg.browser_args))