Watchdog added, managing multiple browser instances

server-web.py

@@ -1,30 +1,30 @@
 from seleniumwire import webdriver  # Import from seleniumwire
 from seleniumwire.utils import decode
 from time import sleep
-from collections import deque
 from flask import Flask as f
 from flask import Response
 from dateutil import parser
 from datetime import datetime, timedelta, timezone
 import json
 import re
+import asyncio
+import logging
+import threading
+import os
+
+#log = logging.getLogger('werkzeug')
+#log.setLevel(logging.ERROR)
+#log.disabled = True
+
 
-options = webdriver.ChromeOptions()
-options.add_argument('--headless')
-options.add_argument("--incognito")
-options.add_argument("--nogpu")
-options.add_argument("--disable-gpu")
-options.add_argument("--window-size=1280,1280")
-options.add_argument("--no-sandbox")
-options.add_argument("--enable-javascript")
-options.add_argument('--disable-dev-shm-usage')
 
 # Create a new instance of the Chrome driver
-driver = webdriver.Chrome(options=options)
-q = deque()
 valuestore = {}
 datestore = {}
+lastUpdate = datetime.now(timezone.utc)
+
 app = f("web")
+#app.logger.disabled = True
 h2 = timedelta(hours=2)
 
 def interceptor(request, response):  # A response interceptor takes two args
@@ -37,12 +37,30 @@ def interceptor(request, response):  # A response interceptor takes two args
                 handleJson(j)
             except ValueError:
                 if i.find("online-level") > 0:
-                    print ("Fixed: ", i)
+                    #print ("Fixed: ", i)
                     j = json.loads(i[:i.rfind(']') + 1])
                     handleJson(j)
-                else:
-                    print ("Err: ", i)
+                #else:
+                    #print ("Err: ", i)
 
+# StackOverflow
+def killChildren(driver):
+    print('Quitting session: ',  driver.session_id)
+    driver.quit()
+    try:
+        pid = True
+        while pid:
+            pid = os.waitpid(-1, os.WNOHANG)
+            print("Reaped child: ", str(pid))
+
+            try:
+                if pid[0] == 0:
+                    pid = False
+            except:
+                pass
+
+    except ChildProcessError:
+        pass
 
 def idIsRecent(id):
     return id in valuestore and datetime.now(timezone.utc) - parser.parse(datestore[id]) < timedelta(seconds=30)
@@ -60,7 +78,7 @@ def handleJson(jsonObj):
 # Gibt den letzten bekannten Wert fuer die NMTID zurueck
 @app.route('/nmt/<int:id>')
 def nmtid(id):
-    if id in valuestore and datetime.now(timezone.utc) - parser.parse(datestore[id]) < timedelta(seconds=30):
+    if idIsRecent(id):
         return format( valuestore[id], '.1f')
     else:
         return "E_NA" # Entweder out of date oder nicht existent
@@ -71,9 +89,58 @@ def ids():
     l = filter(idIsRecent,list(valuestore.keys()))
     return ','.join(map(str,l))
 
-if __name__ == '__main__':
+def createDriver():
+    options = webdriver.ChromeOptions()
+    options.add_argument('--headless')
+    options.add_argument("--incognito")
+    options.add_argument("--nogpu")
+    options.add_argument("--disable-gpu")
+    options.add_argument("--window-size=1280,1280")
+    options.add_argument("--no-sandbox")
+    options.add_argument("--enable-javascript")
+    options.add_argument('--disable-dev-shm-usage')
+    driver = webdriver.Chrome(options=options)
     driver.response_interceptor = interceptor
+    return driver
 
-    driver.get('https://dus-travis.dus.com/')
+if __name__ == '__main__':
 
-    app.run(host='0.0.0.0', port=80, debug=False)
+    # start flask server
+    threading.Thread(target=lambda: app.run(host='0.0.0.0', port=80, debug=False, use_reloader=False)).start()
+    
+    # wait time to restart will be dynamically adapted, 
+    # if unexpected things happen in chrome or the real world
+    restartWait = timedelta(hours=4)
+
+    # setup webdriver
+    d0 = createDriver()
+
+    # start initial driver
+    d0.get('https://dus-travis.dus.com/')
+    lastaccess = datetime.now(timezone.utc)
+    
+    # loop and restart with restartWait Interval
+    while True:
+        sleep(10)
+        if datetime.now(timezone.utc) > lastaccess + restartWait:
+            d1 = createDriver()
+            d1.get('https://dus-travis.dus.com/')
+            print ("New Failover Driver started, waiting 10 seconds ...")
+            sleep(10)
+            killChildren(d0)
+            del d0
+            print ("Original driver deleted")
+            d0 = createDriver()
+            d0.get('https://dus-travis.dus.com/')
+            print ("Recreating original driver and waiting 10 seconds ...")
+            sleep(10)
+            killChildren(d1)
+            del d1
+            print ("Failover Driver deleted")
+            lastaccess = datetime.now(timezone.utc)
+        l = filter(idIsRecent,list(valuestore.keys()))
+        if len(l) < 1:
+            restartWait = timedelta(seconds=60)
+
+
+