Merge pull request #73 from TeskaLabs/Enhancement/Add-retry-SMTP

Enhancement: SMTP retry mechanism introduction
TeskaLabs · May 21, 2024 · 3a87f4b · 3a87f4b
2 parents aba4394 + db8e436
commit 3a87f4b
Showing 1 changed file with 108 additions and 83 deletions.
diff --git a/asabiris/output/smtp/service.py b/asabiris/output/smtp/service.py
@@ -4,6 +4,7 @@
 import re
 
 import asab
+import asyncio
 import aiosmtplib
 
 from ...output_abc import OutputABC
@@ -56,7 +57,6 @@ def __init__(self, app, service_name="SmtpService", config_section_name='smtp'):
 		self.SenderNameEmailRegex = re.compile(r"<([^<>]*)>\s*([^<>]*)")
 		self.AngelBracketRegex = re.compile(r".*<.*>.*")
 
-
 	async def send(
 		self, *,
 		email_to,
@@ -81,9 +81,12 @@ async def send(
 		:param cc: A list of Cc email addresses.
 		:param bcc: A list of Bcc email addresses.
 		"""
+		if email_cc is None:
+			email_cc = []
+		if email_bcc is None:
+			email_bcc = []
 
 		# Prepare Message
-
 		msg = email.message.EmailMessage()
 		msg.set_content(body, subtype='html')
 
@@ -96,14 +99,13 @@ async def send(
 			msg['To'] = ', '.join(formatted_email_to)
 
 		if email_cc is not None:
-			assert isinstance(email_to, list)
+			assert isinstance(email_cc, list)
 			formatted_email_cc = []
 			for email_address in email_cc:
 				formatted_sender, sender_email = self.format_sender_info(email_address)
 				formatted_email_cc.append(sender_email)
 			msg['Cc'] = ', '.join(formatted_email_cc)
 
-
 		if email_subject is not None and len(email_subject) > 0:
 			msg['Subject'] = email_subject
 		else:
@@ -127,85 +129,108 @@ async def send(
 					filename=attachment.FileName
 				)
 
-		# Send the result over SMTP
-		try:
-			result = await aiosmtplib.send(
-				msg,
-				sender=sender,
-				recipients=email_to + email_cc + email_bcc,
-				hostname=self.Host,
-				port=int(self.Port) if self.Port != "" else None,
-				username=self.User,
-				password=self.Password,
-				use_tls=self.SSL,
-				start_tls=self.StartTLS
-			)
-		except aiosmtplib.errors.SMTPConnectError as e:
-			L.warning("Connection failed: {}".format(e), struct_data={"host": self.Host, "port": self.Port})
-			raise ASABIrisError(
-				ErrorCode.SMTP_CONNECTION_ERROR,
-				tech_message="SMTP connection failed: {}.".format(str(e)),
-				error_i18n_key="Could not connect to SMTP host '{{host}}'.",
-				error_dict={
-					"host": self.Host,
-				}
-			)
-		except aiosmtplib.errors.SMTPAuthenticationError as e:
-			L.warning("SMTP error: {}".format(e), struct_data={"host": self.Host})
-			raise ASABIrisError(
-				ErrorCode.SMTP_AUTHENTICATION_ERROR,
-				tech_message="SMTP authentication error: {}.".format(str(e)),
-				error_i18n_key="SMTP authentication failed for host '{{host}}'.",
-				error_dict={
-					"host": self.Host
-				}
-			)
-		except aiosmtplib.errors.SMTPResponseException as e:
-			L.warning("SMTP Error", struct_data={"message": e.message, "code": e.code, "host": self.Host})
-			raise ASABIrisError(
-				ErrorCode.SMTP_RESPONSE_ERROR,
-				tech_message="SMTP response exception: Code {}, Message '{}'.".format(e.code, e.message),
-				error_i18n_key="SMTP response issue encountered for '{{host}}': Code '{{code}}', Message '{{message}}'.",
-				error_dict={
-					"message": e.message,
-					"code": e.code,
-					"host": self.Host
-				}
-			)
-		except aiosmtplib.errors.SMTPServerDisconnected as e:
-			L.warning("Server disconnected: {}; check the SMTP credentials".format(e), struct_data={"host": self.Host})
-			raise ASABIrisError(
-				ErrorCode.SMTP_SERVER_DISCONNECTED,
-				tech_message="SMTP server disconnected: {}.".format(str(e)),
-				error_i18n_key="The SMTP server '{{host}}' disconnected unexpectedly.",
-				error_dict={
-					"host": self.Host
-				}
-			)
-		except aiosmtplib.errors.SMTPTimeoutError as e:
-			L.warning("SMTP timeout encountered: {}; check network connectivity or SMTP server status".format(e), struct_data={"host": self.Host})
-			raise ASABIrisError(
-				ErrorCode.SMTP_TIMEOUT,  # Make sure to define this error code appropriately
-				tech_message="SMTP timeout encountered: {}.".format(str(e)),
-				error_i18n_key="The SMTP server for '{{host}}' timed out unexpectedly.",
-				error_dict={
-					"host": self.Host
-				}
-			)
-
-		except Exception as e:
-			L.warning("SMTP error: {}; check credentials".format(e), struct_data={"host": self.Host})
-			raise ASABIrisError(
-				ErrorCode.SMTP_GENERIC_ERROR,
-				tech_message="Generic error occurred: {}.".format(str(e)),
-				error_i18n_key="A generic SMTP error occurred for host '{{host}}'.",
-				error_dict={
-					"host": self.Host
-				}
-			)
-
-		L.log(asab.LOG_NOTICE, "Email sent", struct_data={'result': result[1], "host": self.Host})
-
+		# Send the email with retry logic
+		retry_attempts = 3
+		delay = 5  # seconds
+
+		for attempt in range(retry_attempts):
+			try:
+				result = await aiosmtplib.send(
+					msg,
+					sender=sender,
+					recipients=email_to + email_cc + email_bcc,
+					hostname=self.Host,
+					port=int(self.Port) if self.Port != "" else None,
+					username=self.User,
+					password=self.Password,
+					use_tls=self.SSL,
+					start_tls=self.StartTLS
+				)
+				L.log(asab.LOG_NOTICE, "Email sent", struct_data={'result': result[1], "host": self.Host})
+				break  # Email sent successfully, exit the retry loop
+
+			except aiosmtplib.errors.SMTPConnectError as e:
+				L.warning("Connection failed: {}".format(e), struct_data={"host": self.Host, "port": self.Port})
+				if attempt < retry_attempts - 1:
+					L.info("Retrying email send after connection failure, attempt {}".format(attempt + 1))
+					await asyncio.sleep(delay)
+					continue  # Retry the email sending
+				raise ASABIrisError(
+					ErrorCode.SMTP_CONNECTION_ERROR,
+					tech_message="SMTP connection failed: {}.".format(str(e)),
+					error_i18n_key="Could not connect to SMTP for host '{{host}}'.",
+					error_dict={
+						"host": self.Host,
+					}
+				)
+			except aiosmtplib.errors.SMTPAuthenticationError as e:
+				L.warning("SMTP error: {}".format(e), struct_data={"host": self.Host})
+				raise ASABIrisError(
+					ErrorCode.SMTP_AUTHENTICATION_ERROR,
+					tech_message="SMTP authentication error: {}.".format(str(e)),
+					error_i18n_key="SMTP authentication failed for host '{{host}}'.",
+					error_dict={
+						"host": self.Host
+					}
+				)
+			except aiosmtplib.errors.SMTPResponseException as e:
+				L.warning("SMTP Error", struct_data={"message": e.message, "code": e.code, "host": self.Host})
+				if attempt < retry_attempts - 1:
+					L.info("Retrying email send after connection failure, attempt {}".format(attempt + 1))
+					await asyncio.sleep(delay)
+					continue  # Retry the email sending
+				raise ASABIrisError(
+					ErrorCode.SMTP_RESPONSE_ERROR,
+					tech_message="SMTP response exception: Code {}, Message '{}'.".format(e.code, e.message),
+					error_i18n_key="SMTP response issue encountered for '{{host}}': Code '{{code}}', Message '{{message}}'.",
+					error_dict={
+						"message": e.message,
+						"code": e.code,
+						"host": self.Host
+					}
+				)
+			except aiosmtplib.errors.SMTPServerDisconnected as e:
+				L.warning("Server disconnected: {}; check the SMTP credentials".format(e), struct_data={"host": self.Host})
+				if attempt < retry_attempts - 1:
+					L.info("Retrying email send after connection failure, attempt {}".format(attempt + 1))
+					await asyncio.sleep(delay)
+					continue  # Retry the email sending
+				raise ASABIrisError(
+					ErrorCode.SMTP_SERVER_DISCONNECTED,
+					tech_message="SMTP server disconnected: {}.".format(str(e)),
+					error_i18n_key="The SMTP server for '{{host}}' disconnected unexpectedly.",
+					error_dict={
+						"host": self.Host
+					}
+				)
+			except aiosmtplib.errors.SMTPTimeoutError as e:
+				L.warning("SMTP timeout encountered: {}; check network connectivity or SMTP server status".format(e), struct_data={"host": self.Host})
+				if attempt < retry_attempts - 1:
+					L.info("Retrying email send after connection failure, attempt {}".format(attempt + 1))
+					await asyncio.sleep(delay)
+					continue  # Retry the email sending
+				raise ASABIrisError(
+					ErrorCode.SMTP_TIMEOUT,
+					tech_message="SMTP timeout encountered: {}.".format(str(e)),
+					error_i18n_key="The SMTP server for '{{host}}' timed out unexpectedly.",
+					error_dict={
+						"host": self.Host
+					}
+				)
+			except Exception as e:
+				L.warning("SMTP error: {}; check credentials".format(e), struct_data={"host": self.Host})
+				if attempt < retry_attempts - 1:
+					L.info("Retrying email send after connection failure, attempt {}".format(attempt + 1))
+					await asyncio.sleep(delay)
+					continue  # Retry the email sending
+				raise ASABIrisError(
+					ErrorCode.SMTP_GENERIC_ERROR,
+					tech_message="Generic error occurred: {}.".format(str(e)),
+					error_i18n_key="A generic SMTP error occurred for host '{{host}}'.",
+					error_dict={
+						"host": self.Host
+					}
+				)
 
 	def format_sender_info(self, email_info):
 		"""