Remove cheroot server for now until we find a way to shutdown cheroot using REST call. Fixes #5069.

docs/en_US/release_notes_4_17.rst

@@ -16,7 +16,6 @@ Housekeeping
 ************
 
 | `Issue #4988 <https://redmine.postgresql.org/issues/4988>`_ -  Refactored SQL of Table's and it's child nodes.
-| `Issue #5017 <https://redmine.postgresql.org/issues/5017>`_ -  Use cheroot as default production server for pgAdmin4.
 | `Issue #5023 <https://redmine.postgresql.org/issues/5023>`_ -  Refactored SQL of Views and Materialized Views.
 | `Issue #5024 <https://redmine.postgresql.org/issues/5024>`_ -  Refactored SQL of Functions and Procedures.
 | `Issue #5038 <https://redmine.postgresql.org/issues/5038>`_ -  Added support for on-demand loading of items in Select2.

requirements.txt

@@ -15,7 +15,6 @@
 #       ignored when building a PIP Wheel.
 ##############################################################################
 blinker==1.4
-cheroot==8.2.1
 Flask==1.0.2
 Werkzeug>=0.15.0
 Flask-Gravatar==0.5.0

web/pgAdmin4.py

@@ -13,7 +13,6 @@ to start a web server."""
 
 import os
 import sys
-from cheroot.wsgi import Server as CherootServer
 
 if sys.version_info[0] >= 3:
     import builtins
@@ -191,29 +190,15 @@ if __name__ == '__main__':
     # Reference:
     # https://github.com/pallets/werkzeug/issues/220#issuecomment-11176538
     try:
-        if config.DEBUG:
-            app.run(
-                host=config.DEFAULT_SERVER,
-                port=server_port,
-                use_reloader=(
-                    (not PGADMIN_RUNTIME) and app.debug and
-                    os.environ.get("WERKZEUG_RUN_MAIN") is not None
-                ),
-                threaded=config.THREADED_MODE
-            )
-        else:
-            # Can use cheroot instead of flask dev server when not in debug
-            # 10 is default thread count in CherootServer
-            num_threads = 10 if config.THREADED_MODE else 1
-            prod_server = CherootServer(
-                (config.DEFAULT_SERVER, server_port),
-                wsgi_app=app,
-                numthreads=num_threads,
-                server_name=config.APP_NAME)
-            try:
-                print("Using production server...")
-                prod_server.start()
-            except KeyboardInterrupt:
-                prod_server.stop()
+        app.run(
+            host=config.DEFAULT_SERVER,
+            port=server_port,
+            use_reloader=(
+                (not PGADMIN_RUNTIME) and app.debug and
+                os.environ.get("WERKZEUG_RUN_MAIN") is not None
+            ),
+            threaded=config.THREADED_MODE
+        )
+
     except IOError:
         app.logger.error("Error starting the app server: %s", sys.exc_info())