import hashlib from abc import abstractmethod import chardet import json import logging import os import requests import sys import time visualselector_xpath_selectors = 'div,span,form,table,tbody,tr,td,a,p,ul,li,h1,h2,h3,h4, header, footer, section, article, aside, details, main, nav, section, summary' class Non200ErrorCodeReceived(Exception): def __init__(self, status_code, url, screenshot=None, xpath_data=None, page_html=None): # Set this so we can use it in other parts of the app self.status_code = status_code self.url = url self.screenshot = screenshot self.xpath_data = xpath_data self.page_text = None if page_html: from changedetectionio import html_tools self.page_text = html_tools.html_to_text(page_html) return class checksumFromPreviousCheckWasTheSame(Exception): def __init__(self): return class JSActionExceptions(Exception): def __init__(self, status_code, url, screenshot, message=''): self.status_code = status_code self.url = url self.screenshot = screenshot self.message = message return class BrowserStepsStepTimout(Exception): def __init__(self, step_n): self.step_n = step_n return class PageUnloadable(Exception): def __init__(self, status_code, url, message, screenshot=False): # Set this so we can use it in other parts of the app self.status_code = status_code self.url = url self.screenshot = screenshot self.message = message return class EmptyReply(Exception): def __init__(self, status_code, url, screenshot=None): # Set this so we can use it in other parts of the app self.status_code = status_code self.url = url self.screenshot = screenshot return class ScreenshotUnavailable(Exception): def __init__(self, status_code, url, page_html=None): # Set this so we can use it in other parts of the app self.status_code = status_code self.url = url if page_html: from html_tools import html_to_text self.page_text = html_to_text(page_html) return class ReplyWithContentButNoText(Exception): def __init__(self, status_code, url, screenshot=None): # Set this so we can use it in other parts of the app self.status_code = status_code self.url = url self.screenshot = screenshot return class Fetcher(): error = None status_code = None content = None headers = None browser_steps = None browser_steps_screenshot_path = None fetcher_description = "No description" webdriver_js_execute_code = None xpath_element_js = "" xpath_data = None # Will be needed in the future by the VisualSelector, always get this where possible. screenshot = False system_http_proxy = os.getenv('HTTP_PROXY') system_https_proxy = os.getenv('HTTPS_PROXY') # Time ONTOP of the system defined env minimum time render_extract_delay = 0 def __init__(self): from pkg_resources import resource_string # The code that scrapes elements and makes a list of elements/size/position to click on in the VisualSelector self.xpath_element_js = resource_string(__name__, "res/xpath_element_scraper.js").decode('utf-8') @abstractmethod def get_error(self): return self.error @abstractmethod def run(self, url, timeout, request_headers, request_body, request_method, ignore_status_codes=False, current_include_filters=None, is_binary=False): # Should set self.error, self.status_code and self.content pass @abstractmethod def quit(self): return @abstractmethod def get_last_status_code(self): return self.status_code @abstractmethod def screenshot_step(self, step_n): return None @abstractmethod # Return true/false if this checker is ready to run, in the case it needs todo some special config check etc def is_ready(self): return True def iterate_browser_steps(self): from changedetectionio.blueprint.browser_steps.browser_steps import steppable_browser_interface from playwright._impl._api_types import TimeoutError from jinja2 import Environment jinja2_env = Environment(extensions=['jinja2_time.TimeExtension']) step_n = 0 if self.browser_steps is not None and len(self.browser_steps): interface = steppable_browser_interface() interface.page = self.page valid_steps = filter(lambda s: (s['operation'] and len(s['operation']) and s['operation'] != 'Choose one' and s['operation'] != 'Goto site'), self.browser_steps) for step in valid_steps: step_n += 1 print(">> Iterating check - browser Step n {} - {}...".format(step_n, step['operation'])) self.screenshot_step("before-"+str(step_n)) self.save_step_html("before-"+str(step_n)) try: optional_value = step['optional_value'] selector = step['selector'] # Support for jinja2 template in step values, with date module added if '{%' in step['optional_value'] or '{{' in step['optional_value']: optional_value = str(jinja2_env.from_string(step['optional_value']).render()) if '{%' in step['selector'] or '{{' in step['selector']: selector = str(jinja2_env.from_string(step['selector']).render()) getattr(interface, "call_action")(action_name=step['operation'], selector=selector, optional_value=optional_value) self.screenshot_step(step_n) self.save_step_html(step_n) except TimeoutError: # Stop processing here raise BrowserStepsStepTimout(step_n=step_n) # It's always good to reset these def delete_browser_steps_screenshots(self): import glob if self.browser_steps_screenshot_path is not None: dest = os.path.join(self.browser_steps_screenshot_path, 'step_*.jpeg') files = glob.glob(dest) for f in files: os.unlink(f) # Maybe for the future, each fetcher provides its own diff output, could be used for text, image # the current one would return javascript output (as we use JS to generate the diff) # def available_fetchers(): # See the if statement at the bottom of this file for how we switch between playwright and webdriver import inspect p = [] for name, obj in inspect.getmembers(sys.modules[__name__], inspect.isclass): if inspect.isclass(obj): # @todo html_ is maybe better as fetcher_ or something # In this case, make sure to edit the default one in store.py and fetch_site_status.py if name.startswith('html_'): t = tuple([name, obj.fetcher_description]) p.append(t) return p class base_html_playwright(Fetcher): fetcher_description = "Playwright {}/Javascript".format( os.getenv("PLAYWRIGHT_BROWSER_TYPE", 'chromium').capitalize() ) if os.getenv("PLAYWRIGHT_DRIVER_URL"): fetcher_description += " via '{}'".format(os.getenv("PLAYWRIGHT_DRIVER_URL")) browser_type = '' command_executor = '' # Configs for Proxy setup # In the ENV vars, is prefixed with "playwright_proxy_", so it is for example "playwright_proxy_server" playwright_proxy_settings_mappings = ['bypass', 'server', 'username', 'password'] proxy = None def __init__(self, proxy_override=None): super().__init__() # .strip('"') is going to save someone a lot of time when they accidently wrap the env value self.browser_type = os.getenv("PLAYWRIGHT_BROWSER_TYPE", 'chromium').strip('"') self.command_executor = os.getenv( "PLAYWRIGHT_DRIVER_URL", 'ws://playwright-chrome:3000' ).strip('"') # If any proxy settings are enabled, then we should setup the proxy object proxy_args = {} for k in self.playwright_proxy_settings_mappings: v = os.getenv('playwright_proxy_' + k, False) if v: proxy_args[k] = v.strip('"') if proxy_args: self.proxy = proxy_args # allow per-watch proxy selection override if proxy_override: self.proxy = {'server': proxy_override} if self.proxy: # Playwright needs separate username and password values from urllib.parse import urlparse parsed = urlparse(self.proxy.get('server')) if parsed.username: self.proxy['username'] = parsed.username self.proxy['password'] = parsed.password def screenshot_step(self, step_n=''): screenshot = self.page.screenshot(type='jpeg', full_page=True, quality=85) if self.browser_steps_screenshot_path is not None: destination = os.path.join(self.browser_steps_screenshot_path, 'step_{}.jpeg'.format(step_n)) logging.debug("Saving step screenshot to {}".format(destination)) with open(destination, 'wb') as f: f.write(screenshot) def save_step_html(self, step_n): content = self.page.content() destination = os.path.join(self.browser_steps_screenshot_path, 'step_{}.html'.format(step_n)) logging.debug("Saving step HTML to {}".format(destination)) with open(destination, 'w') as f: f.write(content) def run(self, url, timeout, request_headers, request_body, request_method, ignore_status_codes=False, current_include_filters=None, is_binary=False): from playwright.sync_api import sync_playwright import playwright._impl._api_types self.delete_browser_steps_screenshots() response = None with sync_playwright() as p: browser_type = getattr(p, self.browser_type) # Seemed to cause a connection Exception even tho I can see it connect # self.browser = browser_type.connect(self.command_executor, timeout=timeout*1000) # 60,000 connection timeout only browser = browser_type.connect_over_cdp(self.command_executor, timeout=60000) # Set user agent to prevent Cloudflare from blocking the browser # Use the default one configured in the App.py model that's passed from fetch_site_status.py context = browser.new_context( user_agent=request_headers['User-Agent'] if request_headers.get('User-Agent') else 'Mozilla/5.0', proxy=self.proxy, # This is needed to enable JavaScript execution on GitHub and others bypass_csp=True, # Should be `allow` or `block` - sites like YouTube can transmit large amounts of data via Service Workers service_workers=os.getenv('PLAYWRIGHT_SERVICE_WORKERS', 'allow'), # Should never be needed accept_downloads=False ) self.page = context.new_page() if len(request_headers): context.set_extra_http_headers(request_headers) self.page.set_default_navigation_timeout(90000) self.page.set_default_timeout(90000) # Listen for all console events and handle errors self.page.on("console", lambda msg: print(f"Playwright console: Watch URL: {url} {msg.type}: {msg.text} {msg.args}")) # Goto page try: # Wait_until = commit # - `'commit'` - consider operation to be finished when network response is received and the document started loading. # Better to not use any smarts from Playwright and just wait an arbitrary number of seconds # This seemed to solve nearly all 'TimeoutErrors' response = self.page.goto(url, wait_until='commit') except playwright._impl._api_types.Error as e: # Retry once - https://github.com/browserless/chrome/issues/2485 # Sometimes errors related to invalid cert's and other can be random print ("Content Fetcher > retrying request got error - ", str(e)) time.sleep(1) response = self.page.goto(url, wait_until='commit') except Exception as e: print ("Content Fetcher > Other exception when page.goto", str(e)) context.close() browser.close() raise PageUnloadable(url=url, status_code=None, message=str(e)) # Execute any browser steps try: extra_wait = int(os.getenv("WEBDRIVER_DELAY_BEFORE_CONTENT_READY", 5)) + self.render_extract_delay self.page.wait_for_timeout(extra_wait * 1000) if self.webdriver_js_execute_code is not None and len(self.webdriver_js_execute_code): self.page.evaluate(self.webdriver_js_execute_code) except playwright._impl._api_types.TimeoutError as e: context.close() browser.close() # This can be ok, we will try to grab what we could retrieve pass except Exception as e: print ("Content Fetcher > Other exception when executing custom JS code", str(e)) context.close() browser.close() raise PageUnloadable(url=url, status_code=None, message=str(e)) if response is None: context.close() browser.close() print ("Content Fetcher > Response object was none") raise EmptyReply(url=url, status_code=None) # Run Browser Steps here self.iterate_browser_steps() extra_wait = int(os.getenv("WEBDRIVER_DELAY_BEFORE_CONTENT_READY", 5)) + self.render_extract_delay time.sleep(extra_wait) self.content = self.page.content() self.status_code = response.status if len(self.page.content().strip()) == 0: context.close() browser.close() print ("Content Fetcher > Content was empty") raise EmptyReply(url=url, status_code=response.status) self.status_code = response.status self.content = self.page.content() self.headers = response.all_headers() # So we can find an element on the page where its selector was entered manually (maybe not xPath etc) if current_include_filters is not None: self.page.evaluate("var include_filters={}".format(json.dumps(current_include_filters))) else: self.page.evaluate("var include_filters=''") self.xpath_data = self.page.evaluate("async () => {" + self.xpath_element_js.replace('%ELEMENTS%', visualselector_xpath_selectors) + "}") # Bug 3 in Playwright screenshot handling # Some bug where it gives the wrong screenshot size, but making a request with the clip set first seems to solve it # JPEG is better here because the screenshots can be very very large # Screenshots also travel via the ws:// (websocket) meaning that the binary data is base64 encoded # which will significantly increase the IO size between the server and client, it's recommended to use the lowest # acceptable screenshot quality here try: # The actual screenshot self.screenshot = self.page.screenshot(type='jpeg', full_page=True, quality=int(os.getenv("PLAYWRIGHT_SCREENSHOT_QUALITY", 72))) except Exception as e: context.close() browser.close() raise ScreenshotUnavailable(url=url, status_code=None) context.close() browser.close() class base_html_webdriver(Fetcher): if os.getenv("WEBDRIVER_URL"): fetcher_description = "WebDriver Chrome/Javascript via '{}'".format(os.getenv("WEBDRIVER_URL")) else: fetcher_description = "WebDriver Chrome/Javascript" command_executor = '' # Configs for Proxy setup # In the ENV vars, is prefixed with "webdriver_", so it is for example "webdriver_sslProxy" selenium_proxy_settings_mappings = ['proxyType', 'ftpProxy', 'httpProxy', 'noProxy', 'proxyAutoconfigUrl', 'sslProxy', 'autodetect', 'socksProxy', 'socksVersion', 'socksUsername', 'socksPassword'] proxy = None def __init__(self, proxy_override=None): super().__init__() from selenium.webdriver.common.proxy import Proxy as SeleniumProxy # .strip('"') is going to save someone a lot of time when they accidently wrap the env value self.command_executor = os.getenv("WEBDRIVER_URL", 'http://browser-chrome:4444/wd/hub').strip('"') # If any proxy settings are enabled, then we should setup the proxy object proxy_args = {} for k in self.selenium_proxy_settings_mappings: v = os.getenv('webdriver_' + k, False) if v: proxy_args[k] = v.strip('"') # Map back standard HTTP_ and HTTPS_PROXY to webDriver httpProxy/sslProxy if not proxy_args.get('webdriver_httpProxy') and self.system_http_proxy: proxy_args['httpProxy'] = self.system_http_proxy if not proxy_args.get('webdriver_sslProxy') and self.system_https_proxy: proxy_args['httpsProxy'] = self.system_https_proxy # Allows override the proxy on a per-request basis if proxy_override is not None: proxy_args['httpProxy'] = proxy_override if proxy_args: self.proxy = SeleniumProxy(raw=proxy_args) def run(self, url, timeout, request_headers, request_body, request_method, ignore_status_codes=False, current_include_filters=None, is_binary=False): from selenium import webdriver from selenium.webdriver.common.desired_capabilities import DesiredCapabilities from selenium.common.exceptions import WebDriverException # request_body, request_method unused for now, until some magic in the future happens. # check env for WEBDRIVER_URL self.driver = webdriver.Remote( command_executor=self.command_executor, desired_capabilities=DesiredCapabilities.CHROME, proxy=self.proxy) try: self.driver.get(url) except WebDriverException as e: # Be sure we close the session window self.quit() raise self.driver.set_window_size(1280, 1024) self.driver.implicitly_wait(int(os.getenv("WEBDRIVER_DELAY_BEFORE_CONTENT_READY", 5))) if self.webdriver_js_execute_code is not None: self.driver.execute_script(self.webdriver_js_execute_code) # Selenium doesn't automatically wait for actions as good as Playwright, so wait again self.driver.implicitly_wait(int(os.getenv("WEBDRIVER_DELAY_BEFORE_CONTENT_READY", 5))) # @todo - how to check this? is it possible? self.status_code = 200 # @todo somehow we should try to get this working for WebDriver # raise EmptyReply(url=url, status_code=r.status_code) # @todo - dom wait loaded? time.sleep(int(os.getenv("WEBDRIVER_DELAY_BEFORE_CONTENT_READY", 5)) + self.render_extract_delay) self.content = self.driver.page_source self.headers = {} self.screenshot = self.driver.get_screenshot_as_png() # Does the connection to the webdriver work? run a test connection. def is_ready(self): from selenium import webdriver from selenium.webdriver.common.desired_capabilities import DesiredCapabilities self.driver = webdriver.Remote( command_executor=self.command_executor, desired_capabilities=DesiredCapabilities.CHROME) # driver.quit() seems to cause better exceptions self.quit() return True def quit(self): if self.driver: try: self.driver.quit() except Exception as e: print("Content Fetcher > Exception in chrome shutdown/quit" + str(e)) # "html_requests" is listed as the default fetcher in store.py! class html_requests(Fetcher): fetcher_description = "Basic fast Plaintext/HTTP Client" def __init__(self, proxy_override=None): self.proxy_override = proxy_override def run(self, url, timeout, request_headers, request_body, request_method, ignore_status_codes=False, current_include_filters=None, is_binary=False): # Make requests use a more modern looking user-agent if not 'User-Agent' in request_headers: request_headers['User-Agent'] = os.getenv("DEFAULT_SETTINGS_HEADERS_USERAGENT", 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36') proxies = {} # Allows override the proxy on a per-request basis if self.proxy_override: proxies = {'http': self.proxy_override, 'https': self.proxy_override, 'ftp': self.proxy_override} else: if self.system_http_proxy: proxies['http'] = self.system_http_proxy if self.system_https_proxy: proxies['https'] = self.system_https_proxy r = requests.request(method=request_method, data=request_body, url=url, headers=request_headers, timeout=timeout, proxies=proxies, verify=False) # If the response did not tell us what encoding format to expect, Then use chardet to override what `requests` thinks. # For example - some sites don't tell us it's utf-8, but return utf-8 content # This seems to not occur when using webdriver/selenium, it seems to detect the text encoding more reliably. # https://github.com/psf/requests/issues/1604 good info about requests encoding detection if not is_binary: # Don't run this for PDF (and requests identified as binary) takes a _long_ time if not r.headers.get('content-type') or not 'charset=' in r.headers.get('content-type'): encoding = chardet.detect(r.content)['encoding'] if encoding: r.encoding = encoding if not r.content or not len(r.content): raise EmptyReply(url=url, status_code=r.status_code) # @todo maybe you really want to test zero-byte return pages? if r.status_code != 200 and not ignore_status_codes: # maybe check with content works? raise Non200ErrorCodeReceived(url=url, status_code=r.status_code, page_html=r.text) self.status_code = r.status_code if is_binary: # Binary files just return their checksum until we add something smarter self.content = hashlib.md5(r.content).hexdigest() else: self.content = r.text self.headers = r.headers self.raw_content = r.content # Decide which is the 'real' HTML webdriver, this is more a system wide config # rather than site-specific. use_playwright_as_chrome_fetcher = os.getenv('PLAYWRIGHT_DRIVER_URL', False) if use_playwright_as_chrome_fetcher: html_webdriver = base_html_playwright else: html_webdriver = base_html_webdriver