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

231 lines
11 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
import logging
from changedetectionio.store import ChangeDetectionStore
from changedetectionio import login_optionally_required
browsersteps_live_ui_o = {}
browsersteps_playwright_browser_interface = None
browsersteps_playwright_browser_interface_browser = None
browsersteps_playwright_browser_interface_context = None
browsersteps_playwright_browser_interface_end_time = None
browsersteps_playwright_browser_interface_start_time = None
def cleanup_playwright_session():
global browsersteps_live_ui_o
global browsersteps_playwright_browser_interface
global browsersteps_playwright_browser_interface_browser
global browsersteps_playwright_browser_interface_context
global browsersteps_playwright_browser_interface_end_time
global browsersteps_playwright_browser_interface_start_time
browsersteps_live_ui_o = {}
browsersteps_playwright_browser_interface = None
browsersteps_playwright_browser_interface_browser = None
browsersteps_playwright_browser_interface_end_time = None
browsersteps_playwright_browser_interface_start_time = None
print("Cleaning up old playwright session because time was up, calling .goodbye()")
try:
browsersteps_playwright_browser_interface_context.goodbye()
except Exception as e:
print ("Got exception in shutdown, probably OK")
print (str(e))
browsersteps_playwright_browser_interface_context = None
print ("Cleaning up old playwright session because time was up - done")
def construct_blueprint(datastore: ChangeDetectionStore):
browser_steps_blueprint = Blueprint('browser_steps', __name__, template_folder="templates")
@login_optionally_required
@browser_steps_blueprint.route("/browsersteps_update", methods=['GET', 'POST'])
def browsersteps_ui_update():
import base64
import playwright._impl._api_types
import time
from changedetectionio.blueprint.browser_steps import browser_steps
global browsersteps_live_ui_o, browsersteps_playwright_browser_interface_end_time
global browsersteps_playwright_browser_interface_browser
global browsersteps_playwright_browser_interface
global browsersteps_playwright_browser_interface_start_time
step_n = None
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)
# Because we don't "really" run in a context manager ( we make the playwright interface global/long-living )
# We need to manage the shutdown when the time is up
if browsersteps_playwright_browser_interface_end_time:
remaining = browsersteps_playwright_browser_interface_end_time-time.time()
if browsersteps_playwright_browser_interface_end_time and remaining <= 0:
cleanup_playwright_session()
return make_response('Browser session expired, please reload the Browser Steps interface', 401)
# 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 = None
step_selector = datastore.data['watching'][uuid].get('url')
# @todo try.. accept.. nice errors not popups..
try:
this_session = browsersteps_live_ui_o.get(browsersteps_session_id)
if not this_session:
print("Browser exited")
return make_response('Browser session ran out of time :( Please reload this page.', 401)
this_session.call_action(action_name=step_operation,
selector=step_selector,
optional_value=step_optional_value)
except Exception as e:
print("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 = this_session.page.url
if is_last_step and u:
(screenshot, xpath_data) = this_session.request_visualselector_data()
datastore.save_screenshot(watch_uuid=uuid, screenshot=screenshot)
datastore.save_xpath_data(watch_uuid=uuid, data=xpath_data)
# Setup interface
if request.method == 'GET':
if not browsersteps_playwright_browser_interface:
print("Starting connection with playwright")
logging.debug("browser_steps.py connecting")
global browsersteps_playwright_browser_interface_context
from . import nonContext
browsersteps_playwright_browser_interface_context = nonContext.c_sync_playwright()
browsersteps_playwright_browser_interface = browsersteps_playwright_browser_interface_context.start()
time.sleep(1)
# At 20 minutes, some other variable is closing it
# @todo find out what it is and set it
seconds_keepalive = int(os.getenv('BROWSERSTEPS_MINUTES_KEEPALIVE', 10)) * 60
# keep it alive for 10 seconds more than we advertise, sometimes it helps to keep it shutting down cleanly
keepalive = "&timeout={}".format(((seconds_keepalive+3) * 1000))
try:
browsersteps_playwright_browser_interface_browser = browsersteps_playwright_browser_interface.chromium.connect_over_cdp(
os.getenv('PLAYWRIGHT_DRIVER_URL', '') + keepalive)
except Exception as e:
if 'ECONNREFUSED' in str(e):
return make_response('Unable to start the Playwright session properly, is it running?', 401)
browsersteps_playwright_browser_interface_end_time = time.time() + (seconds_keepalive-3)
print("Starting connection with playwright - done")
if not browsersteps_live_ui_o.get(browsersteps_session_id):
# Boot up a new session
proxy_id = datastore.get_preferred_proxy_for_watch(uuid=uuid)
proxy = None
if proxy_id:
proxy_url = datastore.proxy_list.get(proxy_id).get('url')
if proxy_url:
proxy = {'server': proxy_url}
print("Browser Steps: UUID {} Using proxy {}".format(uuid, proxy_url))
# Begin the new "Playwright Context" that re-uses the playwright interface
# Each session is a "Playwright Context" as a list, that uses the playwright interface
browsersteps_live_ui_o[browsersteps_session_id] = browser_steps.browsersteps_live_ui(
playwright_browser=browsersteps_playwright_browser_interface_browser,
proxy=proxy)
this_session = browsersteps_live_ui_o[browsersteps_session_id]
if not this_session.page:
cleanup_playwright_session()
return make_response('Browser session ran out of time :( Please reload this page.', 401)
response = None
if request.method == 'POST':
# Screenshots and other info only needed on requesting a step (POST)
try:
state = this_session.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': this_session.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)
elif request.method == 'GET':
# Just enough to get the session rolling, it will call for goto-site via POST next
response = make_response({
'session_age_start': this_session.age_start,
'browser_time_remaining': round(remaining)
})
return response
return browser_steps_blueprint