.gitignore

@@ -0,0 +1,129 @@
+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+*.py,cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+db.sqlite3-journal
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+.python-version
+
+# pipenv
+#   According to pypa/pipenv#598, it is recommended to include Pipfile.lock in version control.
+#   However, in case of collaboration, if having platform-specific dependencies or dependencies
+#   having no cross-platform support, pipenv may install dependencies that don't work, or not
+#   install all needed dependencies.
+#Pipfile.lock
+
+# PEP 582; used by e.g. github.com/David-OConnor/pyflow
+__pypackages__/
+
+# Celery stuff
+celerybeat-schedule
+celerybeat.pid
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/

Dockerfile

@@ -0,0 +1,22 @@
+# pull official base image
+FROM python:3.9.6-alpine
+
+# set work directory
+WORKDIR /usr/src/app
+
+# set environment variables
+ENV PYTHONDONTWRITEBYTECODE 1
+ENV PYTHONUNBUFFERED 1
+
+# install dependencies
+RUN pip install --upgrade pip
+COPY ./requirements.txt .
+RUN pip install -r requirements.txt
+
+# add user
+RUN adduser --disabled-password --gecos '' service
+USER service
+
+# copy project
+COPY . .
+ENTRYPOINT ["/usr/src/app/entrypoint.sh"]

README.md

@@ -1,3 +1,9 @@
 # influx-smtp-gateway
 
 SMTP gateway accessible from InfluxDB for sending alerts.
+
+# create .env file with following parameters
+SMTP_SERVER_HOST = smtp.gmail.com
+TO_MAIL = test111@mailinator.com
+FROM_MAIL = test@gmail.com
+FROM_MAIL_PASSWORD = test@123

docker-compose.yml

@@ -0,0 +1,9 @@
+version: '3.8'
+
+services:
+  smtp-gateway:
+    build: .
+    expose:
+      - "8081"
+    env_file:
+      - ./.env

entrypoint.sh

@@ -0,0 +1,2 @@
+#!/bin/sh
+python main.py

main.py

@@ -0,0 +1,122 @@
+#!/usr/bin/env python3
+"""
+SMTP webhook server
+"""
+
+import os
+import json
+import smtplib
+import sys
+import time
+from email.header import Header
+from email.mime.text import MIMEText
+
+import cherrypy
+import logging
+
+logging.basicConfig(stream=sys.stdout,
+                    format='%(name)s - %(levelname)s - %(message)s')
+
+
+class SMTPWebhookApp:
+    """
+    SMTP webhook server
+    """
+
+    def _send_mail(self):
+
+        if not cherrypy.request.headers.get('Content-Length'):
+            logging.error("error: Invalid content length.")
+            return {"status": 400, "message": "Invalid content length."}
+
+        cl = cherrypy.request.headers['Content-Length']
+        rawbody = cherrypy.request.body.read(int(cl))
+        req_body = json.loads(rawbody)
+
+        if not req_body.get('subject') or req_body.get('subject') == '':
+            logging.error("error: body field is required.")
+            return {"status": 400, "message": "subject field is required."}
+
+        if not req_body.get('body') or req_body.get('body') == '':
+            logging.error("error: body field is required.")
+            return {"status": 400, "message": "body field is required."}
+
+        if not req_body.get('to_mail') or req_body.get('to_mail') == '':
+            logging.error("error: to_mail field is required.")
+            return {"status": 400, "message": "to_mail field is required."}
+
+        subject = req_body['subject']
+        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
+
+    @cherrypy.expose
+    def send_mail(self):
+        """
+        api endpoint for send mail
+        """
+        data = self._send_mail()
+        cherrypy.response.status = data["status"]
+        cherrypy.response.headers["Content-Type"] = "application/json"
+        return json.dumps(data["status"]).encode()
+
+
+ROOT = SMTPWebhookApp()
+
+SMTP_SERVER_PORT = 587
+CHERRYPY_SERVER_HOST = "0.0.0.0"
+CHERRYPY_SERVER_PORT = 8081
+
+if __name__ == "__main__":
+    try:
+        SMTP_SERVER_HOST = os.environ["SMTP_SERVER_HOST"]
+        FROM_MAIL = os.environ["FROM_MAIL"]
+        FROM_MAIL_PASSWORD = os.environ["FROM_MAIL_PASSWORD"]
+    except KeyError:
+        raise KeyError("Please check missing environment variables: "
+                       "SMTP_SERVER_HOST, FROM_MAIL, "
+                       "FROM_MAIL_PASSWORD")
+
+    cherrypy.server.socket_host = CHERRYPY_SERVER_HOST
+    cherrypy.server.socket_port = CHERRYPY_SERVER_PORT
+    ENGINE = cherrypy.engine
+
+    cherrypy.tree.mount(ROOT, config={})
+
+    if hasattr(ENGINE, "signal_handler"):
+        ENGINE.signal_handler.subscribe()
+    if hasattr(ENGINE, "console_control_handler"):
+        ENGINE.console_control_handler.subscribe()
+    try:
+        ENGINE.start()
+    except Exception:  # pylint: disable=broad-except
+        sys.exit(1)
+    else:
+        ENGINE.block()

requirements.txt

@@ -0,0 +1,15 @@
+cheroot==8.6.0
+CherryPy==18.6.1
+importlib-resources==5.4.0
+jaraco.classes==3.2.1
+jaraco.collections==3.5.1
+jaraco.context==4.1.1
+jaraco.functools==3.5.0
+jaraco.text==3.7.0
+more-itertools==8.12.0
+portend==3.1.0
+pytz==2021.3
+six==1.16.0
+tempora==5.0.1
+zc.lockfile==2.0
+zipp==3.7.0