From ac8fe8261eae35452f0fd02ecced0fd9a421c6f9 Mon Sep 17 00:00:00 2001
From: "kuldeep.k@cisinlabs.com" <kuldeep.k@cisinlabs.com>
Date: Wed, 23 Feb 2022 20:15:56 +0530
Subject: [PATCH] Updated the smtp client object handling logic by thread local
 client variable

---
 main.py | 74 ++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 50 insertions(+), 24 deletions(-)

diff --git a/main.py b/main.py
index e0554d3..b163b93 100644
--- a/main.py
+++ b/main.py
@@ -13,11 +13,18 @@ from email.mime.text import MIMEText
 
 import cherrypy
 import logging
+import threading
+
 
 logging.basicConfig(stream=sys.stdout,
                     format='%(name)s - %(levelname)s - %(message)s')
 
 
+def soft_return(msg):
+    time.sleep(0.2)
+    return(msg)
+
+
 class SMTPWebhookApp:
     """
     SMTP webhook server
@@ -49,33 +56,49 @@ class SMTPWebhookApp:
         body = req_body['body']
         to_mail = req_body['to_mail']
 
-        try:
-            client = smtplib.SMTP(host=SMTP_SERVER_HOST, port=SMTP_SERVER_PORT)
-        except (smtplib.SMTPConnectionError, TimeoutError) as e:
-            time.sleep(0.2)
-            logging.error("To: {}, error: {}".format(to_mail, e))
-            return {"status": 400, "message": "SMTP client error: {}.".format(
-                    e)}
-
         msg = MIMEText(body, 'plain', 'utf-8')
         msg['Subject'] = Header(subject, 'utf-8')
         msg['From'] = FROM_MAIL
         msg['To'] = to_mail
-        try:
-            client.ehlo()
-            client.starttls()
-            client.ehlo()
-            client.login(msg["From"], FROM_MAIL_PASSWORD)
-            client.sendmail(msg['From'], msg['To'], msg.as_string())
-            response = {"status": 200, "message": "mail sent successfully"}
-            logging.info("To: {}, mail sent successfully".format(to_mail))
-        except smtplib.SMTPException as e:
-            time.sleep(0.2)
-            logging.error("To: {}, error: {}".format(to_mail, e))
-            response = {"status": 500, "message": "some error: {}".format(e)}
-        finally:
-            client.quit()
-            return response
+
+        c = 0
+        while (c < 2):
+            try:
+                mythread.client.sendmail(msg['From'],
+                                         msg['To'], msg.as_string())
+                response = {"status": 200, "message": "mail sent successfully"}
+            except (AttributeError, ValueError,
+                    smtplib.SMTPServerDisconnected):
+                if (c == 1):
+                    soft_return("can't connect")
+                try:
+                    print("- - - - - CREATING CLIENT - - - - -")
+                    mythread.client = smtplib.SMTP(host=SMTP_SERVER_HOST,
+                                                   port=SMTP_SERVER_PORT)
+                    mythread.client.starttls()
+                except (smtplib.SMTPException, TimeoutError) as e:
+                    soft_return("can't connect")
+                    response = {"status": 500,
+                                "message": "some error: {}".format(e)}
+                    print("response1: ", response)
+
+                try:
+                    mythread.client.login(msg["From"], FROM_MAIL_PASSWORD)
+                except smtplib.SMTPException as e:
+                    soft_return(e)
+                    response = {"status": 500,
+                                "message": "some error: {}".format(e)}
+                    print("response2: ", response)
+
+            except smtplib.SMTPException as e:
+                soft_return("can't send for some reason")
+                response = {"status": 500,
+                            "message": "some error: {}".format(e)}
+                print("response3: ", response)
+            finally:
+                c += 1
+
+        return response
 
     @cherrypy.expose
     def send_mail(self):
@@ -89,7 +112,6 @@ class SMTPWebhookApp:
 
 
 ROOT = SMTPWebhookApp()
-
 SMTP_SERVER_PORT = 587
 CHERRYPY_SERVER_HOST = "0.0.0.0"
 CHERRYPY_SERVER_PORT = 8081
@@ -109,6 +131,10 @@ if __name__ == "__main__":
     ENGINE = cherrypy.engine
 
     cherrypy.tree.mount(ROOT, config={})
+    mythread = threading.local()
+    mythread.client = smtplib.SMTP(host=SMTP_SERVER_HOST,
+                                   port=SMTP_SERVER_PORT)
+    mythread.client.starttls()
 
     if hasattr(ENGINE, "signal_handler"):
         ENGINE.signal_handler.subscribe()
-- 
2.45.1