feat: support use with statement to create a ftpserver temporarily

docs/tutorial.rst

@@ -65,6 +65,25 @@ and a range of `passive ports <api.html#pyftpdlib.handlers.FTPHandler.passive_po
         main()
 
 
+Use with context
+^^^^^^^^^^^^^^^^
+
+.. code-block:: python
+
+    authorizer = DummyAuthorizer()
+    authorizer.add_anonymous(".")
+    handler = FTPHandler
+    handler.authorizer = authorizer
+    server = FTPServer(("localhost", port), handler)
+    with FTPServerContext(server):
+        with FTP() as ftp:
+            ftp.connect(host='localhost', port=port)
+            ftp.login()
+            print(ftp.dir())
+            print("get the directory successfully first time")
+    print("now the ftpserver has been closed automatically")
+
+
 Logging management
 ==================
 

pyftpdlib/servers.py

@@ -318,6 +318,40 @@ def close_all(self):
         return self.ioloop.close()
 
 
+class FTPServerContext():
+    """
+    use the FTPServerContext
+
+        with FTPServerContext(FTPServer):
+            do_something
+        # auto close the FTPServer
+    """
+
+    def __init__(self, server):
+        self.server = server
+        self.thread = None
+
+    def __enter__(self):
+        logger.debug("you are in FTPServerContext now!")
+        self.start_thread()
+        return
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        logger.debug("you are existing FTPServerContext")
+        self.server.close_all()
+        self.thread.join()
+        return
+
+    def start_thread(self):
+        logger.debug("the FTPServer is running")
+        self.thread = threading.Thread(
+            group=None,
+            target=self.server.serve_forever,
+        )
+        self.thread.start()
+        return
+
+
 # ===================================================================
 # --- extra implementations
 # ===================================================================

pyftpdlib/test/test_context_server.py

@@ -0,0 +1,58 @@
+"""
+test run a ftpserver using with statement
+"""
+
+import random
+
+from ftplib import FTP
+
+from pyftpdlib.servers import FTPServer, FTPServerContext
+from pyftpdlib.authorizers import DummyAuthorizer
+from pyftpdlib.handlers import FTPHandler
+
+from pyftpdlib.test import PyftpdlibTestCase
+from pyftpdlib.test import unittest
+
+
+# logging.basicConfig(level=logging.INFO)
+
+
+class ContextServerTest(PyftpdlibTestCase):
+
+    def test_context(self):
+        port = random.randint(10000, 20000)
+        authorizer = DummyAuthorizer()
+        authorizer.add_anonymous(".")
+        handler = FTPHandler
+        handler.authorizer = authorizer
+        server = FTPServer(("localhost", port), handler)
+        with FTPServerContext(server):
+            with FTP() as ftp:
+                ftp.connect(host='localhost', port=port)
+                ftp.login()
+                # time.sleep(1)
+                print(ftp.dir())
+                print("get the directory successfully first time")
+
+    def test_auto_close(self):
+        port = random.randint(10000, 20000)
+        authorizer = DummyAuthorizer()
+        authorizer.add_anonymous(".")
+        handler = FTPHandler
+        handler.authorizer = authorizer
+        server = FTPServer(("localhost", port), handler)
+        with FTPServerContext(server):
+            with FTP() as ftp:
+                ftp.connect(host='localhost', port=port)
+                ftp.login()
+                # time.sleep(1)
+                print(ftp.dir())
+                print("get the directory successfully first time")
+        with self.assertRaises(ConnectionRefusedError):
+            with FTP() as ftp:
+                ftp.connect(host='localhost', port=port)
+                ftp.login()
+
+
+if __name__ == "__main__":
+    unittest.main()