Purpose

This is a script that connects to Google's Gmail Service through its API. Collects a select set of emails. Then based on the contents of these emails. Sends LINE message Notifications. This could be modified to send messages to other services, Discord, Telegram and more.

Package Installation

If you are not interested in using the line_notify module. Remove it before using pip.

pip3 install -r requirements.txt

Create some required files.

constants.py

Give these constants slightly more memorable / understandable names. This file simplifies the management when processing emails from several different sources.

FROM_1 = "local@domain"
FROM_2 = "local@domain2"

SUB_1 = "Subject Line"
SUB_2 = "Subject Line"

SUBJECTS = [SUB_1, SUB_2]

secrets.py

This file is where you might keep some of your secrets. Though I would probably recommend that you move these to being environment variables instead.
Note: You should have this file listed in your .gitignore file. It should not be uploaded to GitHub.

SEARCH_STRING = "GMail search String"

# Notifier laben ID
LABEL_ID = "Gmail Label ID String"

LINE_TOKEN = "My Secret Token for LINE"

NAME = "A Name"

Running the script

If you found this code first on github, I would direct you to this article series. This will walk you through setting things up with Google.

After going to the Google Quick start. You should have downloaded your credentials.json file. Run the gmail-sample.py

First Run

This will confirm that you are connecting to gmail successfully. If you do not see a list of labels. Work through the google trouble shooting.

If successful delete the following code:

# Stage 1 Check Connection
list_labels_on_setup(service)
sys.exit(0)
# Delete from service = get_service() to this line

Second Run

In the code you will need to set the varible name to some label name you wish to use.
Then run the script. This will report the label_id that google assigned to this new label. For simplicity, don't manually create the label.
Add the label_id to the secrets.py file.

Delete the next section of code:

# Stage 2 Create New Label
  if secrets.LABEL_ID == "":
      print("We are creating a new label.")
      # Replace "" with the label name you wish to use.
      name = ""
      if len(name) == 0:
          print("You have not yet set name See 'name = ""' in the code above")
          print("Do that now and run the script again")
          sys.exit(0)
      new_label = define_label(name)
      new_label = add_label_to_gmail(service, new_label, logger)
      print(f"Your new label ID is: {get_new_label_id(new_label)}")
      print("Set this in secrets.py")
      sys.exit(0)
  # Delete from service = get_service() to this line

At this point you should have a working sample code.

Customising the script.

You will need to update the code in the following section:

if notifier == "NOTE1":
    logger.debug("Note1")
    # Your custom code goes here. Bot / Line
    processed = True
elif notifier == "NOTE2":
    logger.debug("Note2")
    # Your custom code goes here. Bot / Line
    processed = True

If you are confused. Take a look at gmail.py which is my current working implementation.

Automating Script Execution

You can either use good old Cron or systemd. I have included a copy of the two files for systemd which should be located in the /etc/systemd/system/ directory on your system.
You will need to modify the path details and the timers to your own needs.