signals & simple background tasks

Author: chrisjsimpson

.env.example

@@ -4,6 +4,19 @@ TELEGRAM_PYTHON_LOG_LEVEL=ERROR
 TELEGRAM_TOKEN=123456789:ABCDEFG_HIJKLMN_OPQ
 TELEGRAM_CHAT_ID=-87654321
 
+SITE_ADMIN_EMAIL=me@example.com
+
+SMTP_MAILHOST_HOST=email.example.com
+SMTP_MAILHOST_PORT=25
+SMTP_FROMADDR=alerts@example.com
+SMTP_TOADDRS=alerts@example.com
+SMTP_SUBJECT="Log alert"
+SMTP_CREDENTIALS_EMAIL=alerts@example.com
+SMTP_CREDENTIALS_PASSWORD=changeme
+SMTP_SECURE=()
+SMTP_TIMEOUT=3
+
+
 GITHUB_OAUTH_CLIENT_ID=changeme-get-from-github
 GITHUB_OAUTH_CLIENT_SECRET=changeme-get-from-github
 GITHUB_OAUTH_REDIRECT_URI="https://example.com/githubcallback"

app.py

@@ -23,6 +23,7 @@
 import secrets
 from dotenv import load_dotenv
 import subprocess
+from signals import signal_new_repo
 
 log = logger
 
@@ -175,6 +176,9 @@ async def githubcallback(request):
     req = requests.get("https://api.github.com/user/emails", headers=headers)
     email = req.json()[0].get("email", None)
 
+    # Signal that a new repo is created
+    signal_new_repo.send()
+
     # Create a repo for organisation user has access to
     # req = requests.post("https://api.github.com/orgs/karmacomputing/repos", headers=headers, data=json.dumps(data))
     # Create repo for authenticated user
@@ -535,10 +539,14 @@ async def blog(request):
 
 async def health(request):
     log.debug(request)
-    log.error("Testing error logging is working")
     return PlainTextResponse("OK")
 
 
+async def notify(request):
+    log.info(request)
+    return PlainTextResponse("Notification sent")
+
+
 async def not_found(request: Request, exc: HTTPException):
     return HTMLResponse(content="404", status_code=exc.status_code)
 
@@ -563,6 +571,7 @@ async def robots(request: Request):
     Route("/health", health, methods=["GET"]),
     Route("/githubcallback", githubcallback, methods=["GET"]),
     Route("/heroku-alternatives", blog, methods=["GET"]),
+    Route("/notify", notify, methods=["GET"]),
     Route("/{path:path}", catch_all),
 ]
 

email_tools.py

@@ -0,0 +1,58 @@
+import os
+from dotenv import load_dotenv
+import background
+
+load_dotenv()
+
+SMTP_MAILHOST_HOST = os.getenv("SMTP_MAILHOST_HOST")
+SMTP_MAILHOST_PORT = int(os.getenv("SMTP_MAILHOST_PORT"))
+
+SMTP_MAILHOST = (
+    SMTP_MAILHOST_HOST,
+    SMTP_MAILHOST_PORT,
+)  # noqa: E501
+SMTP_FROMADDR = os.getenv("SMTP_FROMADDR")
+SMTP_TOADDRS = os.getenv("SMTP_TOADDRS")
+SMTP_SUBJECT = os.getenv("SMTP_SUBJECT")
+SMTP_CREDENTIALS_EMAIL = os.getenv("SMTP_CREDENTIALS_EMAIL")
+SMTP_CREDENTIALS_PASSWORD = os.getenv("SMTP_CREDENTIALS_PASSWORD")  # noqa: E501
+SMTP_CREDENTIALS = (
+    SMTP_CREDENTIALS_EMAIL,
+    SMTP_CREDENTIALS_PASSWORD,
+)
+SMTP_SECURE = os.getenv("SMTP_SECURE")
+if SMTP_SECURE == "()":
+    SMTP_SECURE = ()
+else:
+    SMTP_SECURE = None
+
+SMTP_TIMEOUT = int(os.getenv("SMTP_TIMEOUT"))
+
+
+@background.task
+def send_email(subject, from_email, to_email, body):
+    try:
+        # Import smtplib for the actual sending function
+        import smtplib
+
+        # Import the email modules we'll need
+        from email.message import EmailMessage
+
+        # Create a text/plain message with body
+        msg = EmailMessage()
+        msg.set_content(body)
+        msg["Subject"] = subject
+        msg["From"] = from_email
+        msg["To"] = to_email
+
+        # Send the message via our own SMTP server.
+        s = smtplib.SMTP(host=SMTP_MAILHOST_HOST, port=SMTP_MAILHOST_PORT)
+        s.connect(SMTP_MAILHOST_HOST, SMTP_MAILHOST_PORT)
+        s.starttls()
+        s.login(
+            user=SMTP_CREDENTIALS_EMAIL, password=SMTP_CREDENTIALS_PASSWORD
+        )  # noqa: E501
+        s.send_message(msg)
+        s.quit()
+    except Exception as e:
+        print(f"Could not send email: {e}")

requirements.txt

@@ -8,3 +8,5 @@ cryptography
 PyNaCl
 GitPython
 coloredlogs
+blinker
+background

signals.py

@@ -0,0 +1,24 @@
+from blinker import signal
+from logger import logger
+from email_tools import send_email
+import os
+
+log = logger
+
+SITE_ADMIN_EMAIL = os.getenv("SITE_ADMIN_EMAIL")
+
+# Signals
+signal_new_repo = signal("signal_new_repo")
+
+# Signal subscribers:
+
+
+def signal_subscriber_new_repo(sender):
+    log.info(f"signal_subscriber_new_repo signal caught by sender {sender}")
+    send_email(
+        "New repo created", SITE_ADMIN_EMAIL, SITE_ADMIN_EMAIL, "New repo created"
+    )
+
+
+# Bind Signals to subscribers
+signal_new_repo.connect(signal_subscriber_new_repo)