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changedetection.io/changedetectionio/blueprint/browser_steps/__init__.py

242 lines
10 KiB

# HORRIBLE HACK BUT WORKS :-) PR anyone?
#
# Why?
# `browsersteps_playwright_browser_interface.chromium.connect_over_cdp()` will only run once without async()
# - this flask app is not async()
# - browserless has a single timeout/keepalive which applies to the session made at .connect_over_cdp()
#
# So it means that we must unfortunately for now just keep a single timer since .connect_over_cdp() was run
# and know when that reaches timeout/keepalive :( when that time is up, restart the connection and tell the user
# that their time is up, insert another coin. (reload)
#
# Bigger picture
# - It's horrible that we have this click+wait deal, some nice socket.io solution using something similar
# to what the browserless debug UI already gives us would be smarter..
#
# OR
# - Some API call that should be hacked into browserless or playwright that we can "/api/bump-keepalive/{session_id}/60"
# So we can tell it that we need more time (run this on each action)
#
# OR
# - use multiprocessing to bump this over to its own process and add some transport layer (queue/pipes)
from distutils.util import strtobool
from flask import Blueprint, request, make_response
import os
from changedetectionio.store import ChangeDetectionStore
from changedetectionio.flask_app import login_optionally_required
from loguru import logger
browsersteps_sessions = {}
io_interface_context = None
def construct_blueprint(datastore: ChangeDetectionStore):
browser_steps_blueprint = Blueprint('browser_steps', __name__, template_folder="templates")
def start_browsersteps_session(watch_uuid):
from . import nonContext
from . import browser_steps
import time
global browsersteps_sessions
global io_interface_context
# We keep the playwright session open for many minutes
keepalive_seconds = int(os.getenv('BROWSERSTEPS_MINUTES_KEEPALIVE', 10)) * 60
browsersteps_start_session = {'start_time': time.time()}
# You can only have one of these running
# This should be very fine to leave running for the life of the application
# @idea - Make it global so the pool of watch fetchers can use it also
if not io_interface_context:
io_interface_context = nonContext.c_sync_playwright()
# Start the Playwright context, which is actually a nodejs sub-process and communicates over STDIN/STDOUT pipes
io_interface_context = io_interface_context.start()
keepalive_ms = ((keepalive_seconds + 3) * 1000)
base_url = os.getenv('PLAYWRIGHT_DRIVER_URL', '').strip('"')
a = "?" if not '?' in base_url else '&'
base_url += a + f"timeout={keepalive_ms}"
try:
browsersteps_start_session['browser'] = io_interface_context.chromium.connect_over_cdp(base_url)
except Exception as e:
if 'ECONNREFUSED' in str(e):
return make_response('Unable to start the Playwright Browser session, is it running?', 401)
else:
# Other errors, bad URL syntax, bad reply etc
return make_response(str(e), 401)
proxy_id = datastore.get_preferred_proxy_for_watch(uuid=watch_uuid)
proxy = None
if proxy_id:
proxy_url = datastore.proxy_list.get(proxy_id).get('url')
if proxy_url:
# Playwright needs separate username and password values
from urllib.parse import urlparse
parsed = urlparse(proxy_url)
proxy = {'server': proxy_url}
if parsed.username:
proxy['username'] = parsed.username
if parsed.password:
proxy['password'] = parsed.password
logger.debug(f"Browser Steps: UUID {watch_uuid} selected proxy {proxy_url}")
# Tell Playwright to connect to Chrome and setup a new session via our stepper interface
browsersteps_start_session['browserstepper'] = browser_steps.browsersteps_live_ui(
playwright_browser=browsersteps_start_session['browser'],
proxy=proxy)
# For test
#browsersteps_start_session['browserstepper'].action_goto_url(value="http://example.com?time="+str(time.time()))
return browsersteps_start_session
@login_optionally_required
@browser_steps_blueprint.route("/browsersteps_start_session", methods=['GET'])
def browsersteps_start_session():
# A new session was requested, return sessionID
import uuid
global browsersteps_sessions
browsersteps_session_id = str(uuid.uuid4())
watch_uuid = request.args.get('uuid')
if not watch_uuid:
return make_response('No Watch UUID specified', 500)
logger.debug("Starting connection with playwright")
logger.debug("browser_steps.py connecting")
browsersteps_sessions[browsersteps_session_id] = start_browsersteps_session(watch_uuid)
logger.debug("Starting connection with playwright - done")
return {'browsersteps_session_id': browsersteps_session_id}
@login_optionally_required
@browser_steps_blueprint.route("/browsersteps_image", methods=['GET'])
def browser_steps_fetch_screenshot_image():
from flask import (
make_response,
request,
send_from_directory,
)
uuid = request.args.get('uuid')
step_n = int(request.args.get('step_n'))
watch = datastore.data['watching'].get(uuid)
filename = f"step_before-{step_n}.jpeg" if request.args.get('type', '') == 'before' else f"step_{step_n}.jpeg"
if step_n and watch and os.path.isfile(os.path.join(watch.watch_data_dir, filename)):
response = make_response(send_from_directory(directory=watch.watch_data_dir, path=filename))
response.headers['Content-type'] = 'image/jpeg'
response.headers['Cache-Control'] = 'no-cache, no-store, must-revalidate'
response.headers['Pragma'] = 'no-cache'
response.headers['Expires'] = 0
return response
else:
return make_response('Unable to fetch image, is the URL correct? does the watch exist? does the step_type-n.jpeg exist?', 401)
# A request for an action was received
@login_optionally_required
@browser_steps_blueprint.route("/browsersteps_update", methods=['POST'])
def browsersteps_ui_update():
import base64
import playwright._impl._errors
global browsersteps_sessions
from changedetectionio.blueprint.browser_steps import browser_steps
remaining =0
uuid = request.args.get('uuid')
browsersteps_session_id = request.args.get('browsersteps_session_id')
if not browsersteps_session_id:
return make_response('No browsersteps_session_id specified', 500)
if not browsersteps_sessions.get(browsersteps_session_id):
return make_response('No session exists under that ID', 500)
# Actions - step/apply/etc, do the thing and return state
if request.method == 'POST':
# @todo - should always be an existing session
step_operation = request.form.get('operation')
step_selector = request.form.get('selector')
step_optional_value = request.form.get('optional_value')
step_n = int(request.form.get('step_n'))
is_last_step = strtobool(request.form.get('is_last_step'))
if step_operation == 'Goto site':
step_operation = 'goto_url'
step_optional_value = datastore.data['watching'][uuid].get('url')
step_selector = None
# @todo try.. accept.. nice errors not popups..
try:
browsersteps_sessions[browsersteps_session_id]['browserstepper'].call_action(action_name=step_operation,
selector=step_selector,
optional_value=step_optional_value)
except Exception as e:
logger.error(f"Exception when calling step operation {step_operation} {str(e)}")
# Try to find something of value to give back to the user
return make_response(str(e).splitlines()[0], 401)
# Get visual selector ready/update its data (also use the current filter info from the page?)
# When the last 'apply' button was pressed
# @todo this adds overhead because the xpath selection is happening twice
u = browsersteps_sessions[browsersteps_session_id]['browserstepper'].page.url
if is_last_step and u:
(screenshot, xpath_data) = browsersteps_sessions[browsersteps_session_id]['browserstepper'].request_visualselector_data()
datastore.save_screenshot(watch_uuid=uuid, screenshot=screenshot)
datastore.save_xpath_data(watch_uuid=uuid, data=xpath_data)
# if not this_session.page:
# cleanup_playwright_session()
# return make_response('Browser session ran out of time :( Please reload this page.', 401)
# Screenshots and other info only needed on requesting a step (POST)
try:
state = browsersteps_sessions[browsersteps_session_id]['browserstepper'].get_current_state()
except playwright._impl._api_types.Error as e:
return make_response("Browser session ran out of time :( Please reload this page."+str(e), 401)
# Use send_file() which is way faster than read/write loop on bytes
import json
from tempfile import mkstemp
from flask import send_file
tmp_fd, tmp_file = mkstemp(text=True, suffix=".json", prefix="changedetectionio-")
output = json.dumps({'screenshot': "data:image/jpeg;base64,{}".format(
base64.b64encode(state[0]).decode('ascii')),
'xpath_data': state[1],
'session_age_start': browsersteps_sessions[browsersteps_session_id]['browserstepper'].age_start,
'browser_time_remaining': round(remaining)
})
with os.fdopen(tmp_fd, 'w') as f:
f.write(output)
response = make_response(send_file(path_or_file=tmp_file,
mimetype='application/json; charset=UTF-8',
etag=True))
# No longer needed
os.unlink(tmp_file)
return response
return browser_steps_blueprint