Monitor journald in real time and get Telegram messages when patterns match.

If you don't have a Telegram bot, go ahead and create one. This will give you the access token for your bot. Next, you need to start a conversation with it and send at least one message. Then you can do curl https://api.telegram.org/bot<TOKEN>/getUpdates and the JSON response will contain an id value in the chat object. This is your chat id.

Copy settings.config.TEMPLATE to settings.config and enter both your bot's token, as well as the chat id of the conversation you have with it. Then enter your regular expression that you want to watch the journal for.

Once everything is configured, simply run ./telegrep and whenever the pattern you defined in the configuration is encountered in the systemd journal, you will receive a message with that line from the log. For testing purposes, you can write messages to the journal with logger "This is my message".

Edit telegrep.service and change the user to the one you want to run it with. Ideally, this is an unprivileged user, but keep in mind that it may need to be in the systemd-journal group to have access to the journal. Also update both paths to point to where you keep the directory. After that, the installation could be something like this:

# Copy the unit file to the appropriate location
sudo cp telegrep.service /etc/systemd/system/
# Start it
sudo systemctl start telegrep
# Check the status
systemctl status telegrep
# Enable it to start on boot
sudo systemctl enable telegrep

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