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gh-christianlouis-docuelevate/app/tasks/imap_tasks.py
T
Christian Krakau-Louis f234a55b52 Added locking for IMAP tasks
2025-02-18 04:29:33 +01:00

265 lines
8.7 KiB
Python

#!/usr/bin/env python3
import os
import json
import email
import imaplib
import logging
import redis # Import Redis for task locking
from datetime import datetime, timedelta, timezone
from celery import shared_task
from app.config import settings
from app.tasks.upload_to_s3 import upload_to_s3
logger = logging.getLogger(__name__)
# Initialize Redis connection using Celery's Redis settings
redis_client = redis.StrictRedis.from_url(settings.redis_url, decode_responses=True)
LOCK_KEY = "imap_lock" # Unique key for locking
LOCK_EXPIRE = 300 # Lock expires in 5 minutes (300 seconds)
# Local cache file for tracking processed emails
CACHE_FILE = os.path.join(settings.workdir, "processed_mails.json")
def acquire_lock():
"""
Attempt to acquire a Redis-based lock. If acquired, set an expiration
time to prevent the lock from remaining stuck if the task crashes.
"""
lock_acquired = redis_client.setnx(LOCK_KEY, "locked")
if lock_acquired:
redis_client.expire(LOCK_KEY, LOCK_EXPIRE)
logger.info("Lock acquired for IMAP processing.")
return True
logger.warning("Lock already held. Skipping this cycle.")
return False
def release_lock():
"""Release the lock by deleting the Redis key."""
redis_client.delete(LOCK_KEY)
logger.info("Lock released.")
def load_processed_emails():
"""Load the list of already processed emails from a local JSON file."""
if os.path.exists(CACHE_FILE):
try:
with open(CACHE_FILE, "r") as f:
processed_emails = json.load(f)
processed_emails = cleanup_old_entries(processed_emails) # Remove old entries
return processed_emails
except json.JSONDecodeError:
logger.warning("Failed to decode JSON, resetting processed emails cache.")
return {}
return {}
def save_processed_emails(processed_emails):
"""Save the processed email IDs to a local JSON file."""
with open(CACHE_FILE, "w") as f:
json.dump(processed_emails, f, indent=4)
def cleanup_old_entries(processed_emails):
"""Remove entries older than 7 days from the cache to avoid infinite growth."""
seven_days_ago = datetime.now(timezone.utc) - timedelta(days=7)
return {
msg_id: date
for msg_id, date in processed_emails.items()
if datetime.strptime(date, "%Y-%m-%dT%H:%M:%S") > seven_days_ago
}
@shared_task
def pull_all_inboxes():
"""
Periodic Celery task that checks all configured IMAP mailboxes
and fetches attachments from new emails.
Ensures only one instance runs at a time using Redis-based locking.
"""
if not acquire_lock():
logger.info("Skipping execution: Another instance is running.")
return
try:
logger.info("Starting pull_all_inboxes")
# Mailbox #1
check_and_pull_mailbox(
mailbox_key="imap1",
host=settings.imap1_host,
port=settings.imap1_port,
username=settings.imap1_username,
password=settings.imap1_password,
use_ssl=settings.imap1_ssl,
delete_after_process=settings.imap1_delete_after_process,
)
# Mailbox #2 (Gmail)
check_and_pull_mailbox(
mailbox_key="imap2",
host=settings.imap2_host,
port=settings.imap2_port,
username=settings.imap2_username,
password=settings.imap2_password,
use_ssl=settings.imap2_ssl,
delete_after_process=settings.imap2_delete_after_process,
)
logger.info("Finished pull_all_inboxes")
finally:
# Ensure the lock is always released
release_lock()
def check_and_pull_mailbox(
mailbox_key: str,
host: str | None,
port: int | None,
username: str | None,
password: str | None,
use_ssl: bool,
delete_after_process: bool,
):
"""
Verifies mailbox configuration and pulls emails from the mailbox if valid.
"""
if not (host and port and username and password):
logger.warning(f"Mailbox {mailbox_key} is missing config, skipping.")
return
logger.info(f"Checking mailbox: {mailbox_key}")
pull_inbox(
mailbox_key=mailbox_key,
host=host,
port=port,
username=username,
password=password,
use_ssl=use_ssl,
delete_after_process=delete_after_process,
)
def pull_inbox(mailbox_key, host, port, username, password, use_ssl, delete_after_process):
"""
Connects to the IMAP inbox, fetches new unread emails from the last 3 days,
processes attachments, and handles flags/labels based on configuration.
"""
logger.info(f"Connecting to {mailbox_key} at {host}:{port} (SSL={use_ssl})")
processed_emails = load_processed_emails()
try:
mail = imaplib.IMAP4_SSL(host, port) if use_ssl else imaplib.IMAP4(host, port)
mail.login(username, password)
mail.select("INBOX")
# Fetch unread emails from the last 3 days
since_date = (datetime.now(timezone.utc) - timedelta(days=3)).strftime("%d-%b-%Y")
status, search_data = mail.search(None, f'(SINCE {since_date} UNSEEN)')
if status != "OK":
logger.warning(f"Search failed on mailbox {mailbox_key}. Status={status}")
mail.close()
mail.logout()
return
msg_numbers = search_data[0].split()
logger.info(f"Found {len(msg_numbers)} unread emails in {mailbox_key}.")
for num in msg_numbers:
status, msg_data = mail.fetch(num, "(RFC822)")
if status != "OK":
logger.warning(f"Failed to fetch message {num} in {mailbox_key}. Status={status}")
continue
raw_email = msg_data[0][1]
email_message = email.message_from_bytes(raw_email)
msg_id = email_message.get("Message-ID")
if not msg_id:
logger.warning(f"Skipping email without Message-ID in {mailbox_key}")
continue
# Skip if already processed
if msg_id in processed_emails:
logger.info(f"Skipping already processed email {msg_id} in {mailbox_key}")
continue
# Process attachments
has_attachment = fetch_attachments_and_enqueue(email_message)
# If it's Gmail, mark processed with star/label
if "gmail" in host.lower():
mark_as_processed_with_star(mail, num)
mark_as_processed_with_label(mail, num, label="Ingested")
# Store processed email
processed_emails[msg_id] = datetime.now(timezone.utc).strftime("%Y-%m-%dT%H:%M:%S")
save_processed_emails(cleanup_old_entries(processed_emails))
# Delete or restore unread status
if delete_after_process:
logger.info(f"Deleting message {num.decode()} from {mailbox_key}")
mail.store(num, "+FLAGS", "\\Deleted")
else:
mail.store(num, "-FLAGS", "\\Seen")
if delete_after_process:
mail.expunge()
mail.close()
mail.logout()
logger.info(f"Finished processing mailbox {mailbox_key}")
except Exception as e:
logger.exception(f"Error pulling mailbox {mailbox_key}: {e}")
def fetch_attachments_and_enqueue(email_message):
"""
Extracts PDF attachments from the email and enqueues them for S3 upload.
Returns:
bool: True if an attachment was found, False otherwise.
"""
has_attachment = False
for part in email_message.walk():
if part.get_content_maintype() == "multipart":
continue
filename = part.get_filename()
content_type = part.get_content_type()
if filename and content_type == "application/pdf":
file_path = os.path.join(settings.workdir, filename)
with open(file_path, "wb") as f:
f.write(part.get_payload(decode=True))
upload_to_s3.delay(file_path)
logger.info(f"Enqueued PDF attachment for upload: {filename}")
has_attachment = True
return has_attachment
def mark_as_processed_with_star(mail, msg_id):
"""Mark email as processed using a star in Gmail."""
try:
mail.store(msg_id, "+FLAGS", "\\Flagged")
logger.info(f"Email {msg_id} starred in Gmail.")
except Exception as e:
logger.error(f"Failed to mark email {msg_id} with star: {e}")
def mark_as_processed_with_label(mail, msg_id, label="Ingested"):
"""Mark email as processed by adding a custom label in Gmail."""
try:
mail.store(msg_id, "+X-GM-LABELS", label)
logger.info(f"Email {msg_id} labeled '{label}' in Gmail.")
except Exception as e:
logger.error(f"Failed to mark email {msg_id} with label {label}: {e}")